Godwin Column: Plants register shock from surprising weather

A combination of conditions unusual for late spring has surprised gardeners.

The recent cold night temperatures and windy wet weather conditions have injured the tender growth on many plants. The weather conditions, combined with the plant's growth stage and plant sensitivity, all have resulted in unusual symptoms resembling cold injury.

In Lenoir County, temperatures dropped into the mid to lower 40s for three nights. Wind gusts have been frequent, with speeds reaching nearly 30 mph.

There has been damage on cucumber plants, tomatoes, peas, calla lily and beauty berry. Other counties are reporting similar damage, including tender vegetables and ornamental plants like oaks, Mandevilla and vinca.

Symptoms observed include areas of the foliage that are bronze, brown, yellow or white between the leaf veins (called interveinal necrosis). The damage is variable, depending on the type of plant, stage of growth, age of plant, actual local temperatures and location of plant.

Though this damage looks serious, the good news is most plants will grow out of it and perform as expected.

Damaged foliage may fall from the plant and be replaced. As long as symptoms do not spread to the new growth, you can assume the damage probably was caused by our recent unusually cold, windy and wet weather.

Watch the new leaves on your plants. If they develop damaged foliage and continue to die, or have round spots surrounded by yellow or reddish tissue, you likely will be dealing with a disease problem. Bring a sample to the Extension Office to be checked, or call the office at (252) 527-2191.

The best thing to do is give the plants time to recover. Leave any foliage on the plant that still has some green color, even if part of the leaf is damaged. After new growth begins to emerge, remove the damaged foliage. Most trees, shrubs and perennials probably will bounce back, sending out new foliage within a few weeks. Established perennials probably will replace foliage that was lost.

Plants that are marginally hardy or plants that were already under stress may not recover quickly. Plants that are not well established may be slower to recover. Wait and see if they send out new growth.

Minimize additional stress by providing additional water when needed. Do not push weakened plants with a heavy application of fertilizer. A small amount of slow-release or water soluble fertilizer might be advantageous when new growth begins to emerge.

Peg Godwin is horticulture agent, Lenoir County Cooperative Extension Center. Reach her at Peg_Godwin@ncsu.edu or (252) 527-2191.