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BY DON MEEHAN
I Sprayed the Plant, but It Didn't Get Any Better!
How often have I heard the phrase, "I sprayed it last week but it doesn't seem to have made a difference". These words are usually followed with a question from me, "What disease did the plant have that caused you to spray it?" and "What material did you spray it with?"
All too often the disease is not clear in their minds as to exactly what it was. Many times the name of the spray has eluded them also, because they weren't told (someone else did the spraying for them).
Dealing with sick and dying plants is a difficult task for most homeowners and not one to be taken lightly. The most challenging aspect for the plant owner is to know what ails the plant. The experience the WSU Diagnostics Center in Puyallup has is that approximately 70-75% of all plant ailments brought to the center are suffering from environmentally related problems, and not insect or disease ailments. Environmentally related problems are those which are brought about because of a poor location for the plant in the landscape, are water influenced, poor soil conditions, injuries from heat, wind or cold, construction damage, nutrient deficiencies, and various other extraneous environmental factors.
The tricky part of diagnosing these environmentally related problems is getting past the often obvious and real signs of disease and insect damage. This damage is often related to environmental problems since such problems increase the stress load on the plant, reducing its ability to ward off insects and disease organisms. A common example I find here in Island County is the obvious damage of wood boring beetles in Douglas fir trees. people usually see this sign first, coming to the conclusion that the beetles are killing the tree, when in fact the beetles, in most cases, would not be present had the tree been in healthy condition.
Many problems of plants begin at the roots. This also makes it difficult to diagnose since this part of the plant is always out of sight, as well as the environment surrounding it, the soil. Wilting plants, an apparent water stress problem, can be brought about in several ways, two of which include environmental; overwatering causing root rots which reduce the plant's ability to take up water, and lack of water applied to the root zone. Knowing which is the culprit can take some detective work.
There is help in sorting out these plant problems. Our office has 45 WSU trained volunteers who can work with homeowners to help them understand their plant problems. These volunteers are backed up by myself and several WSU specialists in horticulture at the WSU Diagnostics Center in Puyallup. Call our office if you would like one of our volunteers to come visit you. They do not charge for this service.
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