Introduction
These and many other questions about the health of plants are constantly asked of Extension personnel, nursery workers, horticulturists, neighbors, anyone thought to have an answer.
“What’s wrong with my plant?”
“Is it dying?” “Can I save it?”
“My plant died. Why?
“What can I do?”
“Can I spray something to save it?”
Sometimes, regrettably, the question is, “What should I have done?” Very seldom is the answer easy. Plants are complex organisms. In Nevada, they seldom live in an “ideal” environment. Plant stress is common: the climate is harsh, and the soils are alkaline, low in organic matter, shallow, often salty, and, as many realize, “nutritionally challenged.” Most importantly, the air and soils in Nevada are dry and without irrigation, most landscape and garden plants do not survive.
To complicate matters, plant diseases and insects abound. Plants without stress have natural defenses against many pests; but when stressed, they may succumb to them. Often, mismanagement in the garden creates plant stress; and unknowingly, gardeners cause or accelerate the demise of their plants. Compacting soils during construction, improper watering, topping trees, selecting poorly adapted plants for a site, applying too much or too little fertilizer—the list goes on—contribute to the poor plant health and loss of plants in the landscape. Sometimes the most trivial condition triggers a chain of events that leads to the death of a plant over time. For example, bark damage from a mower or string trimmer allows a disease organism to enter and eventually kill trees.
Dr. Tom Cook, a plantsman with years of experience learning about stress to plants that leads to their death, developed the Death Spiral of Plants. It is presented on the next page. We have added to it from our experience of growing plants in Nevada and answering questions like the ones above. It must be understood that the most obvious disease, insect or physical damage to a plant is not always the principal reason the plant is in trouble. Most often, selecting plants not adapted to the site’s poor soil conditions, climate or weather, summer heat or winter cold leads to stress and death. Likewise, over watering, soil compaction, drought or just poor management is commonly the root of the plant’s downfall. Insects and pathogens more easily attack a stressed plant: they then weaken it more. Ultimately it may die from the infestation or infection, but the real cause of death occurred earlier when it was damaged or stressed and predisposed to attack by pests.
Look over the Death Spiral of Plants and think about the history of the plants you tend. What can you do to prevent or interrupt the spiral. When a plant is attacked by pests or appears unhealthy, what adjustments may be made to reduce or eliminate the stress that is occurring before it leads to secondary infestations and the death of the plant?
If you are new to Nevada, contact us about successfully growing plants in this high desert.
