After the cold spring, we’ve had with one freeze and several touches of frost, we are all familiar with frost damage. Now that plants are recovering, or not, make a note for future reference. Next spring you will have a better idea about what needs to be covered and what can tough it out.
Effective covers can be anything except sheets of plastic that quickly become the same temperature as the air. I’ve had good luck with old bedsheets, double thickness, over-turned pails and trugs, and, of course, cloches. Many people use empty gallon milk jugs with the bottom cut out, at least for smaller plants. Blankets and towels work but are often too heavy and smash the plant.
If your tree lost its just-emerging leaves, it will regrow another set. Spread some fertilizer under the canopy and several feet out. The tree used energy on the first set of leaves and needs more for the second set. This happens to my ginkgo about every 3 or 4 springs, but this year my mulberry was also affected.
What about other damage throughout the growing season? Sometimes the edges of leaves dry out and become crispy. That is usually a sign of sun damage or hot drying winds, especially in container plants. Move the pot to a more protected area.
Occasionally, variegated-leaved plants will produce a stem with solid green leaves. It’s reverting back to its natural state. Remove the reversion as soon as you discover it. Solid green leaves, having more chlorophyll, are better at photosynthesis and will outcompete the desired variegated leaves.
Hail damage is obvious, causing shredded leaves. This is an easy one. Cut out the damaged leaves, and the plant should produce more, especially if the damage occurs in spring or early summer.
Rotting stems denote over-watering (or raining) resulting in soggy soils over an extended period. Begonias, coleus, succulents, and impatiens are particularly susceptible. Cut back on the water, both frequency and amount. If rain is the problem for in-ground plants, choose a new spot next year that drains faster.
Herbicide damage is hard to diagnose. The symptoms are curled or cupped leaves. However, insects, drought, or disease also cause those symptoms. The first clue is damage only appearing on one side of the plant, facing the direction of the herbicide application. The second clue is a swath of damaged plants. Herbicides don’t jump over several plants to damage just one that is farther in.
Wounded bark on trees is easy to diagnose and requires little help from the homeowner. Remove any jagged pieces, being careful not to cut any healthy bark. The tree will take it from there, drying out the wound and forming a callous. Do not cover the wound with anything. That only promotes moisture, leading to disease.
During this time of COVID-19, the County Extension Offices remain closed. Employees are working from home and can answer your questions via email at uie-cce@illinois.edu. Your horticulture questions will be forwarded to a Master Gardener who will get back to you.