Correcting Plant Damage

If you haven't noticed, plants are not looking their best this year, which seems surprising considering only one hot spot in April and the abundant rain and cooler temperatures of this past spring. But, many trees and shrubs are missing some leaves and branches. Others have spotted or shriveled foliage, and a few lack their natural luster.

Don't panic. The damage is the plant's natural reaction to extreme stress over a long period of time.

It started two summers ago with the mid-summer and early fall droughts of 2000 and 2001. Plants did not receive the water they needed for maximum health of leaves, stems and, especially, roots. Many plants were weakened and parts of the plants died or were badly stunted.

The temperatures were generally cooler and rainfall was so abundant this past May that many plants received too much water and their roots were flooded during the early growth season. As a result, the roots of many plants were weakened or died.

One stressful summer was then followed by a sudden drop in temperature in December 2000 before many plants had become completely dormant for the winter. Normally a plant enters dormancy when daylight shortens and the temperature cools. It slows down and then stops its growth process, and the fluids within the plants begin to change. The fluids act like the antifreeze in a car by allowing the plant to withstand below freezing temperatures.

Due to the sudden drop in temperature, the plant fluid had not completely changed to protect the trees, shrubs and roses. Some internal plant tissue froze, especially the newest growth. As a result, many plants were seriously injured with twig and main stem loses.

Plants that survived the weather of these two years and this spring's heavy bloom period are like a recovering hospital patient who has had a debilitating illness and must now undergo therapy to regain his original vitality.

Recovery takes time. The patient, or the plant, in this case shouldn't be pushed too quickly. The best medicine is time and fertilizer, but perhaps not at full strength. This provides the plant with the necessary nutrients for continuing growth without demanding too much energy use from the plant, as would a full dosage.

For obviously stressed plants, apply a granular fertilizer at approximately 40-50% of the manufacturer's suggested rate right now (before June 21st) and then a full strength application in the fall. Mid-October - November use water-soluble fertilizer at 60-80% of full rate. For flowering plants and broadleaf evergreens, apply one part nitrogen to two parts potassium and phosphate. For leafy plants, reverse this to a ratio of 2:1:1. Roses and evergreens should receive approximately equal parts of all three nutrients.

In addition to fertilizer, make certain that plants receive sufficient water throughout the summer. That means watering the plant until the soil is saturated, but allowing the excess to drain away completely between waterings. An unpainted wood stick inserted a foot deep into the soil can indicate whether the soil is dry, moist, or still wet. In general, water deeply every 10 to 21 days, based on your findings. The timing of waterings will vary in even a smaller yard depending on soil density, etc.

Also maintain a two-inch cover of mulch over plants this summer. It keeps the soil uniformly moist and cool and even protects the planting area from weeds.

Plants have had it rough over the last few years, and the stress is starting to show. But, don't panic. A little tender care over the next few months will get them back to full health.