Wilt assistance

Question: Hello,
I planted a Lindera benzoin in mid-May and noticed a couple of weeks ago the leaves were starting to wilt. On return from lengthy travel the Lindera was dead (see stake to left) and wilt was starting on an Itea virginica planted at the same time (larger plant in lower right). The Itea leaves were falling off but the Lindera leaves did not. I pulled both. The clay soil had been amended with Leafgro compost and the plants came from a reputable native plant nursery. I had a tree diaper around both. Nothing had grown there for a few years and no pesticides were used. How can I tell what kind of wilt this is so I know what to do or re-plant? I have several other natives in the area I don't want to lose. Also could this be from jumping worms? When planting I saw some that didn't look exactly like the online photos but did seem to move more than usual (I bagged them per guidance just in case).

responder: Answered by the Home and Garden Information Center (HGIC), University of Maryland Extension. For timely gardening information and tips, subscribe to our Maryland Grows blog and quarterly newsletter. Follow us on Facebook, Instagram, and YouTube. Replied July 01, 2024, 10:56 AM EDT
response: Was there any watering done other than the one fill-up of the watering bag? This might be excessive drought stress, as most of Maryland is either abnormally dry or in drought currently. Newly-installed plants need close monitoring for watering needs at least twice a week or more in the weather we've had recently. The Itea wilting could be the same drought stress issue, or just an infection that needs to be pruned out. We don't see indications of a particular pathogen in the photos. We do see what looks like landscape fabric used under the mulch, which we would suggest be removed. The fabric makes monitoring for watering needs difficult (since you'd need to be able to feel the soil about six inches deep next to the roots), may trap heat next to surface roots, interfering with evaporative cooling, and might also reduce the available oxygen to the soil below, to the detriment of roots and beneficial soil microbes. (More research needs to be done about the latter impact.)  Landscape fabric also isn't a great long-term solution to weed control, since weeds can eventually germinate on top of it, and if the roots of desirable plants weave into and above it as they grow, that can make later removal of the material very hard to do without damaging lots of roots in the process.  If the Lindera died due to a root rot or crown rot infection, or opportunistic infection like Botryosphaeria, then nothing can be done except to replant, since there is no fungicide useful in those situations. The site conditions are probably fine for the plants, as long as it's not excessively soggy or too drought-prone.  This wilting and die-off would probably not be due to Jumping Worm impacts, if they are indeed present.  Miri

responder: The Question Asker Replied July 01, 2024, 11:46 AM EDT
response: I did water after planting every day for a few days, then every 2-3 days, then tapered off as the plants looked fine except the spicebush. I watered that once it started looking droopy but that didn’t help which is why I assumed it was diseased.   There is no landscape fabric—it’s the tree diaper. These look like donuts that go around each tree or shrub and have some kind of gel inside that captures rain water and slowly releases it. They can be left on over winter and are removed after establishment. The soil under is consistently moist but not overly so. I have used these successfully with trees but it’s the first time with bushes, which is why I watered for the first couple of weeks. I don’t have tree diapers around the smaller perennials so those have been watered twice a week or so depending on the weather.  Nancy

responder: Answered by the Home and Garden Information Center (HGIC), University of Maryland Extension. For timely gardening information and tips, subscribe to our Maryland Grows blog and quarterly newsletter. Follow us on Facebook, Instagram, and YouTube. Replied July 02, 2024, 12:46 PM EDT
response: Thank you for the additional clarification; we had interpreted your "lengthy travel" mention as implying that the plants might not have been getting watered (or checked for watering needs) during that time. While research on water-retentive gels used in materials like "moisture control" potting mixes have not demonstrated effective moisture release to the plant roots, if you found that the soil remained moist several inches below the tree diapers, then perhaps their moisture release was sufficient.  Plants can wilt when over-watered as well as under-watered, as well as when a root rot or similar infection has killed roots or clogged water-conducting tissues in the main stem. That might have been what happened with the Lindera. Organisms that kill roots tend to take advantage of plants under stress, either from overly-wet soil, improper soil pH, or root injury from digging or planting. In this case, it's hard to tell what the original stressor may have been, or if the Lindera was accidentally over-watered or not. Soil pH was probably not a factor in this case, since no nearby plants are showing indications of a nutrient deficiency from soil that isn't acidic enough.  You should be able to replant, though it might be worth checking the soil by hand and watering manually for a time instead of using the tree diaper around a new Lindera, just in case it was not providing adequate moisture to its root zone. Plants also sometimes have the beginnings of an infection (like root rot) that doesn't become symptomatic until the plant experiences more stress, like from high heat (and thus a greater demand on the roots).  Miri

responder: The Question Asker Replied July 02, 2024, 1:02 PM EDT
response: That's helpful--thanks! I will check the soil. I did have friends check and water while I was gone but it was very hot and dry as you mentioned, so I was hoping the tree diapers would cover any gaps. Nancy On Jul 2, 2024, at 12:46 PM, Ask Extension <<personal data hidden>> wrote:   ﻿

responder: Answered by the Home and Garden Information Center (HGIC), University of Maryland Extension. For timely gardening information and tips, subscribe to our Maryland Grows blog and quarterly newsletter. Follow us on Facebook, Instagram, and YouTube. Replied July 02, 2024, 1:03 PM EDT
response: You're welcome.