Why Plants Die
by Ruth S. Foster
It's like trying to explain why babies cry. Many things may be wrong, but knowing which are causes and which are effects is complex. The current plant theory is that plant health starts with healthy roots. A strong, large root system provides the nutrients and moisture that allows vigorous growth. What are some of the reasons for poor roots?
Soil Contaminants Poor roots may result from soil contaminants (like the painter's brush cleaner, or the neighbor's dog). Or perhaps too much compost or improperly cured compost which is too acid (and smells like sewer gas). Plant roots may be also be compromised by herbicides on the lawn, especially under locust and beech trees, which are very sensitive to weed killers put on the lawn. Tree roots actually extend well beyond the leaf canopy.
Drought The long term effect of drought is sick roots. Water is the controlling factor in plant growth so drought weakens the plant. The longer or more often periods of drought occur, the weaker the tree becomes. However, drought itself is usually not the actual cause of death. The actual cause of death, which occurs a few years late, is often a secondary invader - Insect or disease - which follow the weakness brought on by water stress, and inability to fight the invader.
Poor Quality Plants Sometimes plant death is beyond our control, especially with new plants. They may have been sold with poor roots or poor potting soil, or poor care. The soil may have a toxic buildup of fertilizer salts or an undetected fungus. Lots of fertilizer can mask the problem, for a while at least.
Wrong Choice of Plants Poor growth may be caused by poor genes in plants not suited to their ecosystem. The bottom line is: the right plant in the right place will be happier and healthier.