No. 127 

1961 

ROOTING GREENWOOD CUTTINGS 

OF YELLOW BIRCH 

Yellow birch (Betula alleghaniensis Britton) is one of the commercially important species now under study in the hardwood tree-improvement program at our Research center at Burlington, Vt. A preliminary 

step in this program is to acquire information about vegetative propagation. 

There is a complete lack of information about the rooting of yellow 

birch cuttings. Neither Doran1 nor Thimann and Behnke-Rogers2 in their 

comprehensive reviews of rooting woody cuttings make any mention of 

work done on this species. 

This is a report of an exploratory study to determine: (1) whether a 

substantial proportion of greenwood cuttings of yellow birch would root 

under favorable conditions; and, if so, (2) whether rooting is strongly 

related to age of the parent tree. 

Materials and Methods 

One hundred greenwood cuttings, 4 to 5 inches long, were taken 

from each of 6 yellow birch trees on July 21 and 22, 1959. Age of the 

trees at breast height ranged from 11 to 84 years (table 1). 

All except the terminal 3 or 4 leaves were removed from each cutting; 

male catkins, present on many of them, also were removed. The base of 

each cutting was wounded by slicing off a thin, 1-inch-long strip of 

lDoran, William L. Propagation of woody plants by cuttings. Mass. Agr. Expt. Sta. Bul. 491, 

99 pp., illus., 1957. 

ZThimann, K. V.,'and J. Behnke-Rogers. The use of auxins in rooting woody cuttings. Maria 

Moors Cabot Found. Pub. 1, Harvard Forest, Petersham, Mass. 344 pp., illus., 1950. 
Table 1.--Number of yellow birch cuttings rooted, 

by age of parent tree 

phloem from two opposite sides. The cuttings were then dipped in 

Hormodin No. 3, a commercial preparation used to stimulate root development, and were placed at a depth of 1% to 2 inches in a rooting 

medium of perlite. The spacing was 2 by 3 inches. 

Cuttings were kept moist during July and August by an electrically 

controlled overhead, intermittent mist system. Twice each week all cuttings were given foliar applications of a commercial plant food mixed 

with a wetting agent.3 Normal day length was extended by use of overhead incandescent lamps from 9:00 p.m. until midnight. 

Cuttings were scored for rooting during the period October 15-2 1. 

Age of parent tree Cuttings rooted 

(years) 

They were then potted, and the pots were packed in sawdust in flats. 

After the cuttings had hardened off a few weeks, the flats were covered 

with 8 to 10 inches of hardwood leaves and enclosed with hardware 

cloth. A thermograph was installed to measure temperatures above the 

leaf mulch and at root level 2% to 3 inches below the soil level in the 

pots. 

Results and Discussion 

- NO. - NO. 

11 100 2 7 

18 100 7 

25 100 56 

45 100 63 

55 100 22 

84 100 29 

, 

1 

Cuttings tested 

Roots developed on 7 to 63 percent of the cuttings among the six 

individual tree collections (table 1) ; the average for all cuttings was 

34 percent. Cuttings that died after producing a few roots were not 

included in the above figures. Most of the cuttings that rooted developed 

clusters of fairly strong, branching roots up to 4 inches in length. Thus, 

it was demonstrated that yellow birch cuttings can be rooted with a 

moderate degree of success. 

The percentage of rooting success showed no discernible relationship 

to age of parent tree (table 1). Of course data from only 6 trees do 

3Rapid-Gro plant food, mixed by adding 6 heaping teaspoonfuls to 1 gallon of water, with 

3 or 4 drops of Tween wetting agent added. 
• not rule out possible effects of tree age. But they do indicate that, if 

there is a relationship, it is not strongly and consistently expressed. 

As has been found in attempting to grow sugar maple from cuttings, 

formation of roots in the rooting bed does not assure successful propagation.' The crucial hurdle with both species is successful over-wintering. 

Fewer than 5 percent of the 204 rooted yellow birch cuttings survived 

the winter, and these all died soon after breaking dormancy. 

Reasons for the failure have not been positively determined, but they 

do not seem to lie in unfavorable temperatures. The hygrothermograph 

record showed that winter temperatures at the root level of the mulched 

yellow birch cuttings held, with mild fluctuations, around 32'F. 

-WILLIAM J. GABRIEL 

Burlington Research Center 

Northeastern Forest Experiment Station 

Forest Service, U. S. Dept. Agriculture 

Burlington, Vt. 

'Gabriel, William J., Marvin, James W., and Taylor, Fred H. Rooting of greenwood cuttings 

of sugar maple: effect of clone and medium. Northeast. Forest Expt. Sta., Sta. Paper 144, 14 

pp., illus., 1961.