Planting Native Oak 

in the Pacific Northwest

Warren D. Devine and Constance A. Harrington

United States 

Department of 

Agriculture

Forest Service

Pacific Northwest 

Research Station

General Technical 

Report

PNW-GTR-804

February 2010

DEPAR TMENT OF AGRICULT URE
Pesticide Precautionary Statement

This publication reports research involving pesticides. It does not contain recommendations for their use, nor does it imply that the uses discussed here have been 

registered. All uses of pesticides must be registered by appropriate state or federal 

agencies, or both, before they can be recommended.

CAUTION: Pesticides can be injurious to humans, domestic animals, desirable 

plants, and fish or other wildlife if they are not handled properly. Use all pesticides 

selectively and carefully. Follow recommended practices for the disposal of surplus 

pesticides and pesticide containers.

Authors

Warren D. Devine and Constance A. Harrington are research foresters, Forestry 

Sciences Laboratory, 3625 93rd Avenue SW, Olympia, WA 98512-9193.

Cover photos by Warren Devine, Laura Blume, and Michael Wiedmer.

The Forest Service of the U.S. Department of Agriculture is dedicated to the principle of 

multiple use management of the Nation’s forest resources for sustained yields of wood, 

water, forage, wildlife, and recreation. Through forestry research, cooperation with the 

States and private forest owners, and management of the National Forests and National 

Grasslands, it strives—as directed by Congress—to provide increasingly greater service to a 

growing Nation.

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or (202) 720-6382 (TDD). USDA is an equal opportunity provider and employer.
Abstract

Devine, Warren D.; Harrington, Constance A. 2010. Planting native oak in the 

Pacific Northwest. Gen. Tech. Rep. PNW-GTR-804. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 25 p.

The extent of oak woodland and savanna habitat in the Pacific Northwest has been 

dramatically reduced since settlement in the mid-1800s. This report presents a practical guide for landowners and managers who are interested in reestablishing native 

oak by planting seedlings. Keys to successful establishment are (1) planting quality 

seedlings, (2) controlling competing vegetation to increase soil water availability, 

and (3) protecting seedings from animal damage. A variety of effective cultural 

treatments, including mulch and tree shelters, are described in detail. Although 

early growth rates of planted oak seedlings are quite variable, even within the same 

site, this variation decreases over time after the seedlings become established.

Keywords: Oak, planting, regeneration, restoration, Quercus garryana.
Contents

 1 Introduction

 1 Oak in the Pacific Northwest

 2 Where Does Oregon White Oak Occur Naturally?

 4 Where to Plant Oak Seedlings

 4 Planting Locations

 4 Planting Density

 6 Where to Get Oak Seedlings

 6 Nursery Seedlings

 8 Growing Oaks From Acorns

 10 When to Plant Oak Seedlings

 11 The Planting Process

 12 Helping Seedlings Become Established

 12 Vegetative C ompetition

 14 Protection From Browse

 17 Protection From Rodents

 18 Irrigation

 18 Fertilization

 19 Oaks From Sprouts

20 After Planting

20 Maintaining Oak Plantings

 21 Growth R ates

 22 Cost-Share Programs

 23 Additional Resources

 23 Information on Planting Oak

 24 Herbicide Information

 24 Working G roups 

25 Related Research Papers

 25 Acknowledgments
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Planting Native Oak in the Pacific Northwest

Introduction

The goal of this guide is to provide information to help Pacific Northwest 

landowners and land managers through the process of establishing native oaks 

(Quercus spp.). Although none of the treatments or techniques mentioned here 

are mandatory for planting oak seedlings, they are all designed to increase the 

chance of success. This guide is primarily aimed at restoration plantings, from 

hundreds to thousands of seedlings, but most of these techniques also can be used 

by a landowner interested in planting oak on a much smaller scale. Additional 

information sources are listed at the end of the guide.

Oak in the Pacific Northwest

Oak woodlands, savannas, and associated prairies provide a unique habitat in 

a region dominated by conifer forests. Oak trees are an important structural 

component in these unique communities that are home to birds, mammals, reptiles, 

amphibians, invertebrates, and numerous plant species (fig. 1). Acorns produced 

by the oak trees provide a food source for a variety of animals. Oak trees also 

benefit from animals, as establishment of Oregon white oak (Quercus garryana

Dougl. ex Hook.) in new areas occurs primarily through acorn caching by Steller’s 

Figure 1—Many of the best-preserved groves of oak trees in the Pacific Northwest are found in 

parks, around farmsteads, or on military lands.

Warren Devine
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GENERAL TECHNICAL REPORT PNW-GTR-804

jays (Cyanocitta stelleri) and squirrels. The open landscape that characterizes the 

prairie and oak savanna ecosystem was maintained by native peoples for thousands 

of years through their practice of frequent burning. Oaks are among the few tree 

species that tolerated fire. After settlement, fire-suppression, agriculture, urban 

development, and invasion of other species, including Douglas-fir (Pseudotsuga 

menziesii (Mirb.) Franco), resulted in the loss of much of the oak woodland and 

savanna habitat in the coastal Pacific Northwest. Recently, interest in restoring 

these communities has brought about an interest in planting native species 

including oaks.

This guide focuses on Oregon white oak, a deciduous tree also known as Garry 

oak, because it is the most common oak species in the Pacific Northwest and the 

only oak species native to northern Oregon, Washington, and British Columbia. In 

southern Oregon, California black oak (Quercus kelloggii Newberry) and canyon 

live oak (Quercus chrysolepis Liebm.) also occur.1 Much of the technical information presented here may also be of use to those working with the latter two species.

Where Does Oregon White Oak Occur Naturally?

The native range of Oregon white oak extends from southern California to British 

Columbia. In the Pacific Northwest, it is most common in the lowlands west of the 

Cascade Mountain range, although it also occurs east of the Cascades, particularly 

in the vicinity of the Columbia River Gorge. Owing to its tolerance of extreme soil 

conditions, as well as its adaptation to fire, Oregon white oak historically occurred 

on sites where other tree species could not survive. In addition to prairie and 

savanna sites where it tolerated regular burning, Oregon white oak also grows on 

sites prone to winter flooding and on sites that experience harsh summer drought. 

It is found on a wide variety of soil types, ranging from deep riparian soils in the 

Willamette Valley to shallow soils on dry, rocky outcrops.

Oregon white oak has the potential to grow on a wide range of sites, but west 

of the Cascades, it cannot compete for sunlight with taller, faster-growing conifers 

such as Douglas-fir (fig. 2). East of the Cascades, oak is found on drier forest sites 

where it is able to more successfully compete with conifers. Oregon white oak 

is tolerant of shade when young, but after it grows beyond the seedling stage, it 

1 One source for detailed information on other oak species is Burns, R.M.; Honkala, B.H., 

tech. coords. Silvics of North America: Hardwoods. Agric. Handb. 654. Washington, DC: 

U.S. Department of Agriculture, Forest Service. 877 p. http://www.na.fs.fed.us/spfo/pubs/

silvics_manual/volume_2/vol2_Table_of_contents.htm. (September 10, 2009).
3

Planting Native Oak in the Pacific Northwest

becomes shade intolerant and cannot survive long term without direct sunlight. If 

an Oregon white oak tree is overtopped and shaded by adjacent trees, its vigor will 

decline and its limbs will begin to die. There are numerous locations throughout 

western Oregon and Washington and southwestern British Columbia where oak 

trees are dying or already dead because they have become overtopped by conifers 

and do not receive the direct sunlight that they require. Thus, one of the major 

obstacles to establishment of Oregon white oak is competition from other trees.2

The current extent of Oregon white oak has been heavily influenced by human 

activity. Native peoples promoted oak through frequent burning and also transported acorns to new locations. The occurrence of oak within its range was then 

Figure 2—Conifers such as Douglas-fir grow much faster and taller than oak trees. Invasive species, 

including Scotch broom (Cytisus scoparius (L.) Link), the green plant in the foreground, displace 

native herbaceous plants. 

2 Information on releasing oak trees from competition is available in Harrington, C.A.; 

Devine, W.D. 2006. A practical guide to oak release. Gen. Tech. Rep. PNW-GTR-666. 

Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research 

Station. 24 p. http://www.fs.fed.us/pnw/pubs/pnw_gtr666.pdf. (September 10, 2009).

Warren Devine
4

GENERAL TECHNICAL REPORT PNW-GTR-804

substantially reduced by the landscape changes that occurred since settlement. 

However, the mapped native range of Oregon white oak remains quite large.3

Where to Plant Oak Seedlings

Planting Locations

In some instances, the area to be planted is limited in size and there is no question 

where to plant oak seedlings. On larger properties, it may be less obvious where to 

plant oak trees. Historically, the distribution of oaks looked different than it does 

today. In the Willamette Valley and the Puget Sound Region, frequent burning 

produced savannas with scattered, and sometimes very large, oak trees. Denser oak 

woodland stands probably existed on the fringe of such savannas, where fire was 

less frequent and soils were sometimes moister. If a site includes a large open space 

such as a prairie or savanna, planting oak trees around the edges would likely be 

historically accurate and also would preserve the largest area of contiguous open 

space for species requiring that type of habitat. However, seedlings should not be 

planted directly beneath the crowns of other trees, as they will not receive sufficient sunlight (fig. 3). Oaks can be planted on a wide range of soil types, although 

survival rates will almost certainly be lower on very dry or shallow soils and on wet 

soils that are seasonally flooded.

Planting Density

To estimate the desired tree spacing for a restoration planting, it may be helpful to 

visit natural oak stands similar in density to the one that is to be established. It also 

may be helpful to measure the distance between trees in these stands. Densities of 

natural stands range dramatically from savannas with a few scattered oaks to oak 

woodlands with a complete canopy of oak trees. Spacing is typically uneven in 

natural stands; clumps and gaps are common. As long as seedlings are not planted 

on a grid, their arrangement will probably not be distinguishable from a natural one 

once the trees begin to mature. Alternatively, if a management objective is eventual 

timber production, uniform spacing and relatively high density at planting is preferable. Close, uniform spacing is likely to produce taller trees with longer boles (i.e., 

trunks), and wider and irregular spacing encourages development of broad, spreading crowns and relatively short boles (fig. 4). 

3 A range map for Oregon white oak is shown in Stein, W.I. 1990. Oregon white oak. In: 

Burns, R.M.; Honkala, B.H., tech. coords. Silvics of North America: Hardwoods. Agric. 

Handb. 654. Washington, DC: U.S. Department of Agriculture, Forest Service: 650–660. 

http://www.na.fs.fed.us/pubs/silvics_manual/Volume_2/quercus/garryana.htm. (September 

10, 2009).
5

Planting Native Oak in the Pacific Northwest

Figure 3—Oregon white oak seedlings planted in full sunlight outgrow those planted in 

partial sunlight.

Figure 4—These oak seedlings were planted near the edge of an existing stand, in a random arrangement. Planting density is relatively high, in anticipation of natural mortality.

Warren Devine
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GENERAL TECHNICAL REPORT PNW-GTR-804

No matter how much effort is put into an oak planting, it is realistic to expect 

that some of the seedlings will die. Sometimes seedlings die as a result of unforeseen circumstances such as flooding, wildfire, rodent damage, or even unplanned 

mowing operations. For perspective, when oaks reproduce in nature, most of 

their acorns never even become seedlings, and most of the seedlings that become 

established die before they become saplings. For the purposes of this guide, an oak 

is considered to be “established” after it has grown large enough so that mortality from animal damage or summer drought is unlikely. An established oak has 

consistent height and diameter growth each year and is taller than its neighboring 

vegetation. When planting oak, it is not unusual to have 10 to 25 percent mortality 

in the first 2 years and a similar amount of mortality over the next 5 years. A practical approach is to plant two to three times as many trees as are ultimately desired in 

the stand. Trees can always be removed later (or, with great effort, transplanted) if 

too many become established.

The planting approach described here focuses a relatively large amount of effort 

on individual seedlings to maximize survival rate. One reason for this approach is 

the relatively high cost of native oak seedlings compared to, for example, Douglasfir seedlings. Another reason for the intensive approach is that many people planting native oak seedlings are planting a relatively small number of them and have a 

strong interest in seeing the majority of them survive and mature.

Where to Get Oak Seedlings

Nursery Seedlings

Native bareroot and container-grown oak seedlings are produced by an increasing 

number of commercial nurseries in California, Oregon, Washington, and British 

Columbia. Some of these nurseries also carry larger seedlings, saplings, and even 

small trees. Usually, the price of quality nursery seedlings is less than it would cost 

to grow them yourself. Seedling prices differ depending on size, age, and whether 

they are sold in a container or bareroot. Native oak seedlings are in high demand; 

therefore, it is important to begin contacting nurseries well in advance of when the 

seedlings will be needed.

Most nurseries will have several seedling stock types available. These may 

include bareroot seedlings (grown in a nursery bed), plugs (seedlings grown in 

narrow containers), and containerized seedlings (sold in their pots). Seedlings of 

different ages may also be available, price increasing with age. Owing to natural 

genetic variation throughout a species’ range, oak seedlings may grow best if they 

are planted in the same region from which the acorns were collected (e.g., the Puget 

Sound Area, the Willamette Valley, the Columbia River Gorge).
7

Planting Native Oak in the Pacific Northwest

The most important thing to look for in a seedling is a good root system. In 

addition to one or more thick taproots, the seedling should have a large number 

of small lateral roots (fig. 5). These small roots provide greater surface area and 

increased soil contact when a seedling is planted. Better root-soil contact increases 

the seedling’s ability to uptake water and thus improves its early growth and its 

chance of survival. If a seedling has only a few small roots growing from its 

taproot, it will probably not perform well during the first few years, and it may not 

survive. For bareroot seedlings, it is particularly important that they have many 

small roots because this additional root-soil contact helps alleviate the stress that 

the seedling undergoes during its first year after planting. It also is important to 

Figure 5—An ideal root system has numerous small roots that provide good root-soil contact (above); 

a poor-quality root system has few of these small roots (below).

Warren Devine Bridget Korman
8

GENERAL TECHNICAL REPORT PNW-GTR-804

check whether seedlings grown in pots 

are “root bound.” That is, whether the 

taproot is circled around the base of the 

pot. Circled taproots can be very hard to 

straighten at planting time and usually 

have to be pruned off (fig. 6). Clusters of 

small roots at the base of the pot are not 

a problem because they are flexible and 

can be spread out at planting.

A seedling’s diameter at the base of 

its stem (i.e., at the “root collar”) is a general indication of how well it will grow 

during the first few years after planting. 

Whenever possible, choose seedlings that 

have a stem at least 1⁄4 inch (6 mm) in 

diameter. Seedlings of this size and larger 

will be better able to compete with other 

vegetation after they are planted.

Growing Oaks From Acorns

Some people choose to grow their seedlings from acorns. This can be a rewarding 

experience, but it will take 2 years before the seedlings are large enough to plant. 

Raising seedlings also requires diligence throughout the summer to ensure that they 

are adequately watered.

To grow seedlings, acorns should be collected in September or thereabouts, 

when they are yellow to brown and beginning to separate from their caps. Acorns 

still attached to the tree are preferable because they are usually in better condition 

than those on the ground. If acorns must be collected from the ground, they should 

be collected as soon as possible after falling. The most obvious sign that an acorn 

has insect damage is a tiny round hole created by weevils when the larvae exit the 

acorn. A standard test to cull damaged acorns is to soak the acorns in water for 24 

hours just before planting them. The ones that float are much more likely to have 

insect damage; those that sink are usually sound. Of those that sink, larger acorns 

generally produce larger seedlings.

The easiest way to grow oak seedlings is in containers. Regardless of what the 

container is made of, it should be at least 12 inches (30 cm) tall, but it doesn’t necessarily need to be wide (3 to 4 inches [8 to 10 cm] in diameter is sufficient). Initially, 

containers may need to be covered with a piece of screen to keep small animals 

Figure 6—Without proper root management, 

container-grown oak seedlings can become 

“root-bound.” In this case, the “bound” 

portion of the taproot will need to be pruned 

off before planting because it is too thick to 

be straightened.

Warren Devine
9

Planting Native Oak in the Pacific Northwest

from digging up the acorns. Conventional pots can be problematic when growing 

oak seedlings because the seedlings’ roots tend to circle when they reach the base of 

the pot, causing the seedling to become root bound. Some manufacturers sell pots 

that are designed to “air prune” the roots and prevent this problem. These pots are 

shaped to direct the roots toward a large opening at the base of the pot. When the 

downward-growing roots reach this opening, they meet an air gap and stop growing; this prevents root binding and promotes the formation of additional roots away 

from the bottom of the pot. An alternative solution is to use containers that have no 

bottom, such as milk cartons with the bases removed or sections of tube or pipe. 

Any grooves or ridges should run parallel to the length of the container to promote 

downward root growth; perpendicular grooves could cause roots to circle. Place 

the bottomless container on a mesh screen so that the soil does not escape (fig. 7). 

Below the mesh should be an air gap: the screen should not lay directly on another 

surface.

A standard potting soil mix or a combination of potting mix and natural soil 

may be used. Potting mixes are lighter, easier to work with, and provide ideal 

rooting conditions, but they usually do not contain the species of symbiotic fungi 

Figure 7—An example of a setup that will produce oak seedlings with a good root morphology.
10

GENERAL TECHNICAL REPORT PNW-GTR-804

(mycorrhizae) that naturally grow on oak roots in their native environment. Thus, 

seedling growth may benefit from the addition of soil containing these fungi. From 

an oak stand or other forested area, collect soil, including all of the small roots that 

are in it, from within a few inches (centimeters) of the surface (mycorrhizae are 

usually invisible to the naked eye). A small handful of this soil can then be added to 

each pot at planting.

Oregon white oak acorns are ready for planting in the fall as soon as they are 

collected and soaked in water for 24 hours. Place the acorns on their side and cover 

them with about 1⁄2 inch (1 cm) of soil. A taproot will begin to grow within a few 

weeks, and a shoot will appear in spring. Any acorns that have not germinated 

after 1 to 2 months can be discarded and replaced with stored acorns at that time. 

Acorns can be stored under refrigeration for 3 months or more, but the likelihood of 

germination and mold growth increases over time. To store acorns, dry them, place 

them in plastic bags, and refrigerate. For longer storage, rinse acorns in a 5-percent 

bleach solution first, and ensure that the refrigerator is set as close to 33 °F (1 °C) as 

possible.

After acorns are planted in containers, the soil should be checked regularly, 

particularly during summer months, to ensure that it does not become too dry. 

When the containers are irrigated, ensure that the soil is saturated throughout, 

although the pots should not rest in standing water. Seedlings should be fertilized 

regularly throughout the growing season. After the first summer, some seedlings 

may appear large enough to plant; but in the long run, survival and growth rates 

will be higher if the seedlings are grown for 2 years before they are planted in the 

ground.

When to Plant Oak Seedlings

The best time to plant oak seedlings is after rains have moistened the soil in the fall 

and before temperatures begin to warm in early spring. When a seedling is planted 

in fall or winter, rather than in spring, its roots have more time to become established and it will have a better chance of surviving its first summer. An experiment 

showed that seedlings planted by the end of February had greater root growth 

by the beginning of summer compared to seedlings that were planted later in the 

spring. Seedlings planted in the fall have even more time to become established. 

If planting in fall, first dig a hole at least as deep as the planting hole and feel the 

soil to ensure that there has been enough rainfall to moisten it. Spring plantings can 

be just as successful as earlier plantings, but there is a greater chance that summer 

irrigation will be necessary owing to the fact that seedling root systems may not be 

as well established before the soil dries out in the summer.
11

Planting Native Oak in the Pacific Northwest

The Planting Process

Small-scale plantings are often done by hand, but large-scale plantings in soil that 

is rocky or difficult to dig requires a large number of planters or a powered auger. 

An advantage of using a powered auger is that the soil can easily be loosened to 

a greater depth than would normally be achieved with hand tools. This allows the 

seedlings’ roots to more quickly grow into deeper soils that retain more moisture in 

summer.

Begin planting by using a shovel, mattock, or other tool to remove any vegetation from the immediate vicinity (within about 6 to 12 inches [15 to 30 cm]) of the 

planting spot. Then, dig a planting hole several inches (centimeters) deeper and 

several inches wider than the seedling’s root system. Depending on soil type and 

personal preference, a shovel or post-hole digger may work best. If the excavated 

soil is temporarily placed on a tarp or plastic sheet, less soil will be lost before it 

is time to backfill. If planting a containerized seedling that is root-bound, prune 

off any bound portion of the taproot. If a circled taproot is planted, growth will be 

severely hampered. If a bareroot seedling has a thick cluster of small roots, gently 

spread these apart.

Hold the seedling in place with the root collar (the point where the taproot 

becomes the stem) just below ground level, so that you can backfill around the 

roots. For bareroot seedlings, the roots should dangle freely and should not be bent 

(“J-rooted”). Backfill the hole, creating direct contact between seedling roots and 

moist soil; this contact is vital to the seedling’s survival. When backfilling the hole, 

be aware that the deeper the hole is, the more the soil is likely to settle. Pack the soil 

firmly. If the soil is very rocky, additional topsoil should be taken from a nearby 

location to avoid backfilling the hole with a large number of rocks. The root collar 

of the planted seedling should be at, or slightly below, groundline.

On dry sites, it may be beneficial to create a shallow basin around the seedling 

at the time of planting. This will help to direct rainwater or irrigation water toward 

the seedling. A basin can be made by simply creating a slight depression 1 to 2 feet 

(30 to 60 cm) in diameter and optionally adding a low berm 2 to 3 inches (4 to 8 

cm) high around its perimeter.

Special care must be taken when planting bareroot seedlings. Exposing bare 

seedling roots to warm temperatures or dry air at any time prior to planting can 

severely damage the seedlings. Leave bareroot seedlings in storage, keeping them 

damp and cool, until they are ready to be placed in the ground. Always follow 

the nursery’s storage recommendations if the seedlings are not planted soon after 

purchase.
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GENERAL TECHNICAL REPORT PNW-GTR-804

Helping Seedlings Become Established

The planting of tree seedlings or seeds, as opposed to natural regeneration of trees, 

has historically been called artificial regeneration by foresters. With this in mind, 

there are a number of treatments, some rather artificial in appearance, that are 

commonly used to help planted seedlings become established. Major obstacles to 

seedling establishment include competition from other vegetation, damage from 

wildlife, and insufficient soil water before roots become fully established.

Vegetative Competition

Virtually every planted seedling will be negatively affected to some extent by 

competition from adjacent vegetation. Especially in their first year, oak seedlings 

are at a disadvantage because their roots are shallower and less developed and 

their tops are shorter than those of most neighboring plants. Seedling survival and 

early growth rates are nearly always improved by temporarily reducing vegetative 

competition (fig. 8). The most common techniques used for vegetation control are 

mulching, manual removal, and chemical control (i.e., herbicide). Typically, one of 

these three treatments is applied, but two may be combined for even greater control 

of competition.

Figure 8—Two approaches to vegetation control: manual removal (left, photo taken in August of the 

first summer after planting) and plastic mulch (right, photo taken in February).

Warren Devine

Many types of mulch are effective for controlling competition around planted 

seedlings. A variety of materials can be used including a thick layer of organic 

matter, plastic sheeting, woven and nonwoven landscape fabrics, and plastic mats 

specifically designed for seedlings. Several trials in the region have shown that 

perforated plastic mats (often called “Brush Blankets” ® or “weed mats”) work 
13

Planting Native Oak in the Pacific Northwest

well if installed correctly.4 Other 

mulching materials also work well 

assuming they prevent growth 

of most or all of the competing 

vegetation and last for at least 2 

or 3 years. If synthetic materials 

are used, first remove any sticks 

or sharp objects that might poke 

through or tear the material. 

Additionally, the hole from which 

the seedling protrudes must be 

as small as possible, otherwise a 

bouquet of vegetation will emerge 

surrounding the seedling (fig. 9). 

Anchor the edge of the synthetic mulch firmly to the ground with landscape staples 

or rocks. A potential disadvantage of weed mats is that they can be a favored habitat 

for voles (Microtus spp.), which may damage seedlings. Where voles are a problem, 

tree shelters or other seedling protection should be used (see “Protection from 

Rodents” section).

Seedlings will benefit from any size mulch, but mulch that extends at least 2 

feet (60 cm) from the seedling in all directions (i.e., 4 feet [122 cm] in diameter) is 

ideal, as it suppresses most competition and reduces the likelihood that tall grasses 

and other plants will overtop the seedling. A field of large plastic mats is, however, 

visually unattractive to some people, and they may choose to cover synthetic mulch 

with organic materials or to use only organic mulch instead. The combination of 

synthetic and organic mulch is popular for landscaping and effective, but it may be 

prohibitively expensive in large-scale plantings. If purchasing synthetic mulch, it is 

usually more cost-effective to obtain it from the manufacturer or from a forestry or 

landscaping supply company rather than from a retail outlet.

In contrast to mulching, manual removal of competing vegetation requires little 

material cost but usually involves a significant amount of labor. Before planting, use 

a hand tool such as a hoe or pulaski to remove all vegetation from a circular area 

3 to 4 feet (91 to 122 cm) in diameter. Ensure that the thicker roots, especially of 

grasses, are removed to reduce the likelihood of sprouting. After the area is cleared, 

plant the seedling in the center. Followup weeding, at least once per year, is beneficial on most sites.

Figure 9—Because the opening in the center of this 

plastic mulch was larger than necessary, the emerging 

grasses created a significant amount of competition 

close to the seedling.

4 The use of trade or firm names in this publication is for reader information and does not 

imply endorsement by the U.S. Department of Agriculture of any product or service.

James Dollins
14

GENERAL TECHNICAL REPORT PNW-GTR-804

A variety of herbicides can be used, either before or after planting, to eliminate competing vegetation near oak seedlings. For large-scale plantings, chemical 

control of vegetation would likely be much more cost-effective than mulching or 

manual removal. Herbicide may be applied as the sole method of vegetation control, 

or it may be applied prior to mulching. A backpack or canister sprayer may be most 

effective for “spot applying” herbicide to vegetation near each seedling location. 

Follow the label instructions carefully to avoid damaging the seedlings, particularly 

if applying herbicide after planting. See the “Additional Resources” section for 

more information on herbicides.

Protection From Browse 

Tree shelters are commonly used to protect seedlings from a variety of animal 

damages including browse by deer, elk, or cattle, and clipping by rabbits. If the base 

of the shelter is buried in the soil, it also may help protect the seedling from burrowing rodents. On many sites, the likelihood of animal browse makes tree shelters 

a necessity. Solid-walled plastic tree shelters have an additional benefit: they almost 

always increase the height growth rate of seedlings during their first few years after 

planting (fig. 10). This is beneficial in that the seedlings more quickly grow above 

the reach of animals.

There are a wide variety of tree 

shelters commercially available. 

Types include solid-walled shelters, 

solid-walled shelters with vent holes, 

fine-mesh shelters made of synthetic 

cloth, and mesh-walled shelters often 

called Vexar® shelters. Alternatively, 

some people choose to construct their 

own tree shelters. Although the cost 

of a homemade shelter is often higher 

than that of a commercial model, 

homemade shelters allow customization of the dimensions and materials. 

Shelters can be constructed from a 

wide variety of materials, including 

mesh fencing, chicken wire, plastic 

mesh, and netting (fig. 11).

Figure 10—During the first few years after planting (year 0), height growth is 

increased for seedlings grown in solid-walled tree shelters.
15

Planting Native Oak in the Pacific Northwest

In selecting a shelter for oak seedlings, there are several key points to remember. First, the shelter should be tall enough to allow the seedling to “escape” most 

animal damage. For example, in a 3-foot (91-cm)-tall shelter, the seedling may grow 

well for its initial 3 feet, but it then may be browsed by deer for several years after 

it emerges from the top. Although solid-walled shelters increase the rate of seedling height growth, stem diameter growth is not increased, and the result is a tall, 

spindly seedling. This effect is even greater with very tall shelters (i.e., 5 feet [152 

cm]). Thus, the seedlings usually require the continued support of the tree shelter 

for a few years after they emerge from the top of the shelter (fig. 12). One solution 

Figure 11—Five types of tree shelters. Clockwise from top left: a commercially available solidwalled shelter, a mesh-walled Vexar® shelter, and three homemade shelter designs.

Warren Devine
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GENERAL TECHNICAL REPORT PNW-GTR-804

to the problem of the overly 

slender seedling is to use a shelter that is sufficiently wide for 

the seedling to develop a more 

branchy form. A wide mesh 

shelter also allows the seedling 

to sway in the wind, which 

leads to a thicker, sturdier stem. 

For example, 12-inch (30-cm)-

diameter mesh shelters allow 

seedlings to develop naturallooking branches and strong 

stems. However, shelters of this 

width must be homemade, as 

commercial shelters more than 

6 inches (15 cm) in diameter are 

uncommon. If solid-walled plastic shelters are used, it is important to bury the base in the soil. 

Otherwise, the shelter could 

create a chimney effect, and the 

flow of hot air could dry out the 

seedling in summer. The color 

of solid-walled shelters will 

affect the amount of sunlight 

that seedlings receive. Darker 

colors, including blue, should not be used if the seedlings are already receiving 

shade from nearby trees; the combination of a dark-colored shelter plus shade will 

impede photosynthesis. Most types of tree shelters, except those that are designed 

to degrade in sunlight (such as Vexar® shelters), can be reused.

The type of stake used to keep the tree shelter upright is an important decision. 

Generally, the longer lasting stakes are more expensive but have lower maintenance 

and replacement costs. The stake should be long enough to extend at least 1 foot 

(30 cm) beneath the soil surface, and the aboveground portion should be nearly as 

tall, or taller than the shelter. Secure the shelter to the stake at the bottom and top. 

Bamboo stakes are inexpensive, but they will rot over time, and two bamboo stakes 

are needed to secure heavier shelters. Wooden stakes, particularly those made of 

hardwood, last longer than bamboo. Metal fenceposts or rebar are expensive but 

Figure 12—After removal of the solid-walled tree shelter, 

it was apparent that this tall, slender oak seedling lacked 

normal branch development of a seedling its size. Seedlings like this one require the continued support of a tree 

shelter for 2 or 3 more years while the stem thickens and 

branches develop above the top of the shelter.

James Dollins
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Planting Native Oak in the Pacific Northwest

also are extremely durable and reusable. Consider the amount of wind that the site 

receives; solid-walled shelters catch the wind more than mesh shelters and thus put 

more strain on the stake. Round, lightweight garden stakes tend to work themselves 

loose from the ground over time if they are used to support solid-walled shelters.

For protection from animal browse, an alternative to tree shelters is animal 

repellant. Several commercial options are available. Repellants must be applied in 

spring and summer as soon as any new growth is present because young leaves are 

most palatable to deer and elk.

Protection From Rodents

Gophers (Thomomys spp.), voles, and other rodents have the potential to destroy 

planted seedlings, particularly when the rodent population density is high in the 

planting area (fig. 13). The likelihood of damage from gophers can be predicted 

by the presence of mounds. If there is evidence of rodent activity in the planting area, installing barriers around individual seedlings can significantly reduce 

rodent-caused mortality. Because gophers chew the seedling at groundline or below, 

a barrier to prevent damage must extend 8 inches (20 cm) beneath the soil. Lightweight plastic mesh (Vexar® ) tubes, installed around the roots of seedlings at the 

time of planting, have successfully deterred rodents without causing root deformity. 

This material is designed to decompose over time; heavier-weight plastic mesh or 

wire mesh does not decompose and must be removed before root growth becomes 

constricted.

Figure 13—This seedling was severed below ground by a gopher. After this type of damage, the 

seedling’s root system is unlikely to re-sprout. 

James Dollins
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GENERAL TECHNICAL REPORT PNW-GTR-804

Voles typically girdle seedlings aboveground; therefore, seedlings can be 

protected from voles by tree shelters. To keep voles out, the base of the tree shelter 

should be buried 2 to 3 inches (5 to 8 cm) in the soil. If tree shelters are not used, 

vole damage can be reduced by installing a section of plastic tube or pipe around 

the lower stem or by using spiral tree guards or 8-inch (20 cm)-tall tree protectors. 

Voles nest and seek refuge from predators in dense ground vegetation. Removal of 

this vegetation from a site is not always desirable or practical, but in some cases, 

removing it from the vicinity of the planted seedlings can help reduce seedling 

damage.

Irrigation

West of the Cascade Range, the need for irrigation depends on a variety of factors 

including the dryness of the site, the amount of competing vegetation, and the 

planting date. Irrigation of large-scale planting projects can be labor-intensive and 

expensive; thus, it is important to reduce the need for irrigation by planting seedlings with large, healthy root systems, by controlling competing vegetation, and by 

not planting too late in the spring. But irrigation may still be necessary for seedling 

survival on very dry sites, such as those with sandy, gravelly soils and those receiving very little summer rainfall. Abnormally dry spring or summer conditions during the first year after planting may also necessitate irrigation. Observe seedlings 

closely during their first spring and summer; if there are signs of moisture stress, 

such as browning of the leaves, they should be watered soon. The frequency of 

irrigation depends on how quickly the soil dries out; rapidly draining, sandy soils 

may become dry in as little as 1 week. After 1 to 2 years of growth, seedling roots 

become established, and seedlings are less likely to die from moisture stress. East 

of the Cascades, where soil water is less available, irrigation for 1 or more years 

after planting is more likely to be necessary than west of the mountains.

Fertilization

Although fertilization substantially increases the growth rate of potted seedlings, 

fertilization after planting often does not result in a growth increase. Availability 

of soil water is generally a more important factor than nutrients. If fertilizer, either 

manufactured or organic, is used after planting, it should be applied in late spring or 

early summer and placed close to the seedling at the manufacturer’s recommended 

rate.
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Planting Native Oak in the Pacific Northwest

Oaks From Sprouts

Oregon white oak trees often originate from stump sprouts, and root sprouts also 

have been reported. If oak trees are growing in a ring or in a tight clump, that is 

an indication that they probably originated as sprouts from a single stump. Stump 

sprouts usually appear when an existing tree has been cut or severely damaged (fig. 

14). Because sprouts grow from an existing root system, they have a substantial 

advantage over seedlings grown from acorns. Growth rates of sprouts are usually much faster than those of planted seedlings. Thus, if sprouts are present on a 

site, they offer the fastest route to establishing oak trees. Given their existing root 

systems, they can usually outcompete other vegetation, although browse damage is 

a possible threat. 

In some cases, oak saplings or young trees are inadvertently damaged during 

restoration activities. We have found that when small, badly damaged trees are 

cut near the base, they usually form vigorous sprouts that grow more rapidly than 

the original tree had been growing. After the damaged tree is removed, the water 

and nutrients taken up by the root system are diverted to the new sprouts. When 

Figure 14—Where a young oak tree was removed 4 years earlier, a number of vigorous sprouts have 

emerged from around the stump.

James Dollins
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GENERAL TECHNICAL REPORT PNW-GTR-804

a cluster of sprouts is several years old and one or two of the sprouts are clearly 

dominant, the less vigorous sprouts may be pruned off.

After Planting

Maintaining Oak Plantings

Visiting each seedling at least once per year is important for maintenance. 

These visits may include the following activities:

•	 Remove any competing vegetation that has	established	very close to

seedlings.

•	 Ensure that tree shelters are upright, stable, and likely to remain so for

another year.

Figure 15—After the initial establishment period, oak growth rates increase significantly. These 

trees were planted 8 years ago.

Warren Devine
21

Planting Native Oak in the Pacific Northwest

•	 Check that new seedling shoot growth, particularly the terminal shoot (or

“leader”), is not ensnared in the wall of the tree shelter. This is a common 

problem, especially for narrow shelters and shelters with mesh walls. For 

each seedling, verify that the terminal shoot is pointing upward.

•	 Maintain mulch that has been disturbed or damaged. The effectiveness of

mulch or other competition control treatments will gradually deteriorate 

over time, but the seedlings’ need for competition control also will decline. 

However, sometimes quick repairs or maintenance can prolong the lifespan 

of the vegetation control treatment.

•	 Check for animal damage.	Browse	damage by deer or elk	is	easy to assess,

but rodents may damage the seedling stem belowground. If a seedling is in 

poor health for no obvious reason, gently tug on the stem. The seedling will 

come out of the ground easily if the stem or roots have been severed belowground. Unanticipated animal damage may require additional seedling protection measures, such as those described in the earlier section. A variety of 

insects may feed on or otherwise damage oak seedlings, although in many 

cases the damage is not severe enough to seriously impact seedling health 

and survival. State or provincial agricultural extension agents provide pest 

identification services.

•	 Apply additional fertilizer if desired (in late spring or early summer).

Growth Rates

Early growth of planted oak seedlings is often unimpressive because seedlings allocate more of their resources to development of root systems than to stem growth. 

It is not unusual for some seedlings to grow less than 3 inches (8 cm) in height 

annually during the first year or two after planting. However, during the second to 

fourth years postplanting, seedling growth rates usually begin to increase, and the 

amount of annual growth becomes more consistent (fig. 15).

Growth rates differ widely among sites and among seedlings planted on the 

same site. Assuming they are receiving full sunlight, growth rate is positively 

related to the amount of soil water available to seedlings during the summer. 

Vegetation control increases soil water availability to some extent, but the amount 

of soil water is heavily influenced by factors such as soil texture, precipitation 

patterns, and hydrology. Soil properties may differ over small distances, and some 

seedlings grow significantly faster than other seedlings planted nearby. Although 

early growth rates are quite variable, even within the same site, this variation 

decreases over time after the seedlings become established.
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GENERAL TECHNICAL REPORT PNW-GTR-804

Cost-Share Programs

In the United States, federal cost-share programs have been implemented as part 

of the Farm Bill to assist landowners in the development and restoration of wildlife 

habitat. Some of these programs apply to restoration of Oregon white oak woodland 

and savanna habitats. The program best suited to landowners restoring oak habitat 

is the Wildlife Habitat Incentives Program (WHIP). This program is designed to 

improve wildlife habitat that has been negatively affected by agricultural activities, 

urban development, or invasive species. Landowners whose WHIP application 

is accepted work with a representative from the U.S. Department of Agriculture 

Natural Resources Conservation Service (NRCS) to create a 2- to 10-year habitat 

management plan for their property. Landowners receive technical assistance and 

up to 75-percent cost share. Management activities covered by WHIP include planting of native species and control of invasive plants.

A second federal cost-share program that may be available to agricultural 

producers or forest landowners is the Environmental Quality Incentives Program 

(EQIP). This program includes assistance for the protection of habitat for at-risk 

species. The specific activities and habitats covered are determined at the local level 

by the NRCS. Like WHIP, assistance is provided under a multiyear contract, and 

cost share may be as high as 75 percent. For additional information on these U.S. 

cost-share programs, contact the NRCS.

USDA Natural Resources Conservation Service

Find the nearest NRCS office online at:

http://offices.sc.egov.usda.gov/locator/app?agency=nrcs

Learn more about NRCS cost-share programs at:

http://www.nrcs.usda.gov/programs/whip/

http://www.nrcs.usda.gov/programs/eqip/

Washington State NRCS Office

316 W Boone Ave., Suite 450 

Spokane, WA 99201-2348 

Phone: (509) 323-2900 

Fax: (509) 323-2909

Oregon State NRCS Office

1201 NE Lloyd Blvd., Suite 900 

Portland, OR 97232 

Phone: (503) 414-3200 

Fax: (503) 414-3103
23

Planting Native Oak in the Pacific Northwest

California State NRCS Office

430 G Street #4164 

Davis, CA 95616-4164 

Phone: (530) 792-5600 

Fax: (530) 792-5790

Environment Canada’s Habitat Stewardship Program (HSP) works to protect 

species at risk and conserve their habitat. For Canadian restorationists, HSP may 

provide cost-share for planting oak if the project is part of a restoration effort that 

benefits one or more species at risk. The oak ecosystems of British Columbia have 

been a priority of this program in recent years. The HSP is operated through the 

Canadian Wildlife Service.

Canada’s Habitat Stewardship Program

http://www.cws-scf.ec.gc.ca/hsp-pih/default.asp?lang=En&n=59BF488F-1

In British Columbia, contact:

Pacific Wildlife Research Centre

Environment Canada

Canadian Wildlife Service, Pacific and Yukon Region

5421 Robertson Road, RR 1

Delta, BC V4K 3N2

Kin.Mak@ec.gc.ca

Phone: (604) 940-4721

Additional Resources

Information on Planting Oak

Cullington, J.; Dunster, K.; Goulet, L.; Junck, C.; Irwin, G.; Masson, C. 2009. 

The Garry oak gardener’s handbook. 2nd ed. Victoria, Canada: Garry Oak 

Ecosystems Recovery Team Society. 56 p.

This is a guide to creating a garden with oak and associated native plants at a 

relatively small scale. Available at http://www.goert.ca/pubs_general.php.

McCreary, D.D. 2001. Regenerating rangeland oaks in California. Agriculture and 

Natural Resources Publication 21601. Oakland, CA: University of California. 

62 p.

This is a very detailed guide with information that is also applicable to the 

Pacific Northwest. Available through University of California Agriculture and

Natural Resources at http://anrcatalog.ucdavis.edu/.
24

GENERAL TECHNICAL REPORT PNW-GTR-804

Vesely, D.; Tucker, G. 2004. A landowner’s guide for restoring and managing 

Oregon white oak habitats. Salem, OR: U.S. Department of the Interior, Bureau 

of Land Management. 65 p. 

This comprehensive guide has a section on planting oak. Request a copy by 

emailing your name and address to or080mb@or.blm.gov or view online at 

http://www.oregonoaks.org/documents/landguide.pdf.

Herbicide Information

Center for Invasive Species and Ecosystem Health. 2009. Weed control methods 

handbook: tools and techniques for use in natural areas. http://www.invasive.org/

gist/handbook.html. (September 10, 2009).

A comprehensive online guide to herbicide use and other methods of vegetation 

control, with detailed information on specific chemicals.

Hillmer, J.; Liedtke, D. 2003. Safe herbicide handling in natural areas: a guide for 

land stewards and volunteer stewards. Dublin, OH: Ohio Chapter, The Nature 

Conservancy. 20 p.

A brief overview of herbicide use for restoration purposes; some discussion 

of specific chemicals. Go to http://www.invasive.org/gist/products/library/

herbsafe.pdf to download the document.

Miller, T.L. 2009. EXTOXNET—The Extension Toxicology Network. 

http://extoxnet.orst.edu/tics/ghindex.html. (September 10, 2009).

A comprehensive collection of toxicology information on a wide range of 

pesticides (including herbicides).

Ramsay, C.A.; Foss, C.R.; Hines, R.L. 2007. Private applicator pesticide 

education manual. Pullman, WA: Washington State University Cooperative 

Extension. 138 p.

A comprehensive guide to herbicide use, including Washington and 

federal laws; does not describe specific chemicals. Available for $13.50

from http://pubs.wsu.edu or 1-800-723-1763.

Working Groups

Garry Oak Ecosystems Recovery Team (GOERT)

209–606 Courtney Street, Victoria, BC V8W 1B6 Canada

Phone: (250) 383-3427

http://www.goert.ca/ 

Email: info@goert.ca
25

Planting Native Oak in the Pacific Northwest

Oregon Oak Communities Working Group

http://www.oregonoaks.org/ 

Email: oregonoaks@comcast.net.

The South Puget Sound Prairie Landscape Working Group

http://www.southsoundprairies.org/

Related Research Papers

Devine, W.D.; Harrington, C.A.; Leonard, L.P. 2007. Post-planting treatments 

increase growth of Oregon white oak (Quercus garryana Dougl. ex Hook.) 

seedlings. Restoration Ecology. 15(2): 212–222.

Fuchs, M.A.; Krannitz, P.G.; Harestad, A.S. 2000. Factors affecting emergence 

and first-year survival of	seedlings	of Garry oaks	(Quercus garryana) in British 

Columbia, Canada. Forest Ecology and Management. 137: 209–219.

Hibbs, D.E.; Yoder, B.J. 1993. Development of Oregon white oak seedlings. 

Northwest Science. 35: 65–77.

Acknowledgments

We are grateful to the volunteers who collected data from their oak plantings: 

Tanya Braumiller, Dick Hopkins, Hugh Snook, Eric Hendricks, Harold Hertlein, 

Cindy Miner, Rich Wolfe, and Bill Wood. We also thank Lathrop Leonard for his 

oak planting research on Fort Lewis. We thank David Peter, Marty Chaney, Rachel 

Maggi, Jim Evans, Laura Blume, and Douglas McCreary for manuscript reviews. Reese Lolley

Pacific Northwest Research Station

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FAX (503) 808-2130

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Mailing address Publications Distribution

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 P.O. Box 3890

 Portland, OR 97208-3890
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Pacific Northwest Research Station

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