Cumulative Stress on Landscape Plants

Over the last year, I have been observing more and more examples of what I suspect is cumulative stress on trees, shrubs and perennials.  Thinning of formerly thick plants, smaller leaves, dead branches or branch tips, poor color, split bark, holes in the bark, bark lesions/dead areas, or total collapse/death of the plant have all been observed. Attacks on plants from insects, mites and fungus also seem to be on the rise.

Many plants died completely last winter – the winter that would not end.  Several times winter rains turned into ice sheets that were the final straw for plants already stressed by three consecutive years of alternating extremely wet and very dry periods.  This pattern has now extended into the 2013 season with a very late spring, a very wet spring, very nice mid-summer, and now extreme heat and dryness.

It is very easy for landscape plantings to become less vigorous when subjected to this extreme for several consecutive years.  One of the easiest ways to reduce the stress is to water plants deeply during long dry/hot periods if you do not have irrigation that has been providing water on a regular cycle.

Another great way to help out landscape plants in stressful times is to fertilize moderately.  If nutrients are consistently available throughout the growing season plants grow better, look better, and are better able to fend off pests.  Be sure not to over-fertilize.  A little bit of fertilizer is far better than too much, which could damage the roots.

Yet another way to help plants in the landscape is to improve drainage in the root zone.  Chronically waterlogged areas usually stunt and stress most landscape plants.  Re-slope areas, put good gutters and downspouts on the house, re-aim the direction of discharge from sump pump and downspout extensions and break up/break through compacted soil.  Each of these measures will improve drainage to some degree, and added together, the improvement may be significant.

Excessive shade also stresses some landscape plants.  Artful pruning of trees can help a lot and sometimes removal of a tree can help many other plants thrive due to better light availability and less competition in the root zone.

Do what you can to reduce stress on your landscape plants.  We can’t  do much about the weather extremes, but we can do a few things to improve the  situation.