Saturday, July 22, 2017 1:00 am
Gardens, trees hurt by floods
Q. I am concerned about all the flooding that has occurred and how that affects my garden and landscape plants – all which have spent time underwater.
A. According to the National Weather Service, this June we were 3.15 inches above normal precipitation. This trend of flooding rains has continued into July.
Unfortunately, floodwaters contain bacteria and other harmful substances, so vegetables submerged by floodwaters should not be eaten. If fruit like tomatoes or peppers have never been submerged, they are OK.
According to Purdue University experts, when in doubt, throw out food in the home that may have been damaged or spoiled in floods. Keep only foods in undamaged commercial cans, and even then, sanitize the cans before using the food inside. To clean and sanitize cans: Mark the contents on lids of cans with indelible ink and remove paper labels. Wash the cans in a strong detergent solution, using a scrub brush, then immerse the containers for 15 minutes in a solution of 2 teaspoons chlorine bleach and 1 quart of room-temperature water. Air dry the cans.
Be aware that rodents, snakes and other animals may have taken refuge in storm debris in and around your home. Use a stick to move debris, and make noise when approaching.
Landscape trees vary in their response to flooding. The damage from flooding can show up later in the season. Mature trees can handle flooding much better than new or younger trees. Some trees intolerant of flooding include black cherry, eastern white pine, sassafras, white and red oak and hickory.
Black cherry and sassafras in particular are sensitive to rotting of the bark at the base. These trees can be more prone to fall over later.
According to the University of Minnesota, flooding may cause direct damage to trees by changing soil conditions, interrupting normal gas exchange between trees and their environment, sedimentation and physical damage. Flooding also may weaken trees, making them more susceptible to indirect damage from insects and diseases.
The likelihood of insect and disease damage depends upon the severity of the flood and tree health. A tree in weak condition can be further stressed by flooding and consequently susceptible to insects and diseases.
Flood-stressed trees exhibit symptoms that may include leaf chlorosis, dropping leaves, branch and twig dieback, reduced leaf size, early fall coloration and leaf drop, development of small shoots emerging from the main stem and production of either large seed crops or no seed crops in years after a flood. Symptoms may progress and ultimately result in tree death over several years or may abate as the tree recovers.
It is difficult to link a flood to the cause of tree death years later.
Try and avoid planting flood intolerant trees in flood-prone areas and consider using raised beds in areas around the home that are not subject to flooding.