JARS v38n1 - First Aid for Struggling Plants

First Aid for Struggling Plants
William F. Bedwell, Richmond, VA

Reprinted from Middle Atlantic Chapter newsletter.

Do you have azaleas or rhododendrons that seem to dry out faster than others, that have weak foliage color, that struggle along with twigs or branches drying up and dying while your other plants thrive? Frequently, I have revitalized such poor plants by a rather simple method - dig and replant in the same location!
Dig up the plant in a circle 12 to 24 inches wide and 6 to 10 inches deep, depending on plant size and how much weight you can handle. It is best to do this during a dry period in February to April or August to December. Dry soil doesn't weigh as much! Gently probe the lower portion of the soil ball looking for roots. If the original roots have not grown into your soil, most of the soil will fall away. In this case, try to work or wash some of those original roots free of the original growing medium (if the roots are still living). You may find there are no living roots except in the surface mulch or soil surface. For this situation, work the outer half of these surface roots down into the soil when replanting. Where you find a good root system, stop probing.
Before replanting in the same location, rework the remaining soil around the hole, mixing in compost, peat moss or other organic matter, some gypsum (land plaster) and maybe a little superphosphate and some good soil until the entire surface is 2 to 4 inches above ground level after lightly tamping and before replanting. (Protect the plant roots from drying while doing this.)
Replant with the root surface 2 to 4 inches above ground level but leaving a slight ridge of soil around the perimeter of the root area to facilitate watering. Mulch and soak well; then water weekly during dry weather.
Every time I have used this method the azalea or rhododendron has revived and thrived. Those suffering winter freeze or root rot usually die before you have time to try this method, but sometimes raising the plant and working roots into your soil will allow recovery from stress related diseases. If the problem was caused by rodents or insects eating the roots, these pests must be discouraged. Try another location if you suspect the problem was caused by too much exposure to sun, wind, underground rock, hardpan, root competition from maples or other trees with excessive surface roots, too heavy soil or excess water.
In future plantings, try working some of the roots out into your soil by washing away some soil from field grown plants or cutting and spreading out some of the roots of potted plants. Once into your soil, the roots are more likely to continue growing into it. Also, set the plant 2 to 4 inches above ground level to allow for settling over the next few years - especially when you mix liberal quantities of organic matter into your soil before planting, as I do.
An easier revival method that has worked for me on plants that have not settled below ground level is to sprinkle rotted wood liberally around the base of the stems or trunk and over the root surface. I have only used rotted hardwood, and partially rotted pine bark. I don't know if rotted pine wood will work as well. Put a mulch on top of this and fertilize in the spring. Apparently, this may cause enough new roots to form to revive the plant permanently.
A 1 to 2 inch mulch of fresh or partly rotted hickory nuts and hulls has also permanently revived ailing azaleas for me, but some extra fertilizer is a must. Squirrels usually eat any whole nuts on the spot, but watch for sprouting hickories the following spring and pull them quickly before the tap root makes this difficult. Hickory nuts take years to fully decompose and azalea and rhododendron roots seem to love them. Used coffee grounds and tea leaves also are reported to have beneficial effects. Pecans and other hulls also may be effective.