A plant expert once told me that he had a stock answer for people who came to him with the question, “What’s wrong with my plant?” ”The problem,” he would always say, “is that your plant has not been properly cared for. The problem is you.”
This response, while often appropriate, is not always fair. People frequently have mistaken impressions of what plants should look like or unrealistic expectations of how plants should perform.
It is undeniable that the plants growing in our homes and in our gardens are dependent almost entirely upon us. When these plants stop growing or turn yellow, it is often because of neglect, but it may also be due to the season. Hibiscus leaves turn yellow as the result of abrupt changes in temperature or soil moisture level, yet these changes have less impact on a plant that is growing in fertile, well-drained soil.
Sometimes, the problem is overindulgence. On occasion, we decide that we are really going to look after a plant and then spoil it to death with too much water or fertilizer. It appears, often enough, that we are never quite up to the task of caring for our plants. The time and attention they need are denied them, or given too freely, or in the wrong way.
A plant that grows well is perfectly suited to the spot where it is placed. Take a walk in the woods, along the beach or through the chaparral. Perfect plant specimens are growing everywhere. They are not being watered or pruned or fertilized. By summer’s end, many of them look wan or piqued or even wilted, but we know that rain soon will revive them. Our attitude toward plants in the wild is worlds apart from our attitude toward plants in the garden. On a nature walk, there is something miraculous about a sticky-leaved monkey flower or a towering alder tree. In the garden, we see a monkey flower and want to know, primarily, how long it blooms, or we stand under an alder tree and ask, “But does it make a mess?”
“Pests of Landscape Trees and Shrubs” (University of California, Publication 3359; $32) addresses the question of what to expect from a plant by introducing us to the concept of “aesthetic threshold,” which is our tolerance for imperfection in the garden. In the words of the authors, ”Aesthetic tolerance varies with the attitude and knowledge of people using the landscape. . . . Certain plants growing wild as ground covers are tolerated or enjoyed by one segment of the public, while another group
considers them weeds. . . .
Damage that is acceptable on out-of-the-way plants may not be tolerable on prominent plants. Organisms such as gall-forming insects and mites or a few leaf-chewing caterpillars may cause no real harm to plants but can be annoying or even frightening to some.”
“Pests of Landscape Trees and Shrubs” is the best book currently in print on ornamental plant problems. It is a companion to an earlier volume, ”Pests of the Garden and Small Farm,” which deals with pest control on fruit trees and vegetables. Both books contain excellent photographs and pithy information on how to manage common garden pests. They may be ordered by calling (800) 994-8849.
The two most important chapters in the book are 3 and 6, neither of which describes how to kill pests. Chapter 3 deals with the conditions necessary for growing healthy trees and shrubs so that pests won’t visit your garden in the first place. Chapter 6 describes abiotic disorders – problems caused by temperature extremes, insufficient light, compacted soil, improper watering or mineral deficiencies. These disorders are ultimately responsible for many types of insect infestation and fungus disease.