Q. I am concerned about all the flooding that has occurred and how that affects my garden and landscape plants – all of which have spent time underwater this past week. (Editor’s note: This question was submitted during storms that occurred in late June and early July.)

A. The weather, always unpredictable, continues to frustrate gardeners in our area. We went from near-drought conditions after a wet, cool spring to flooding conditions with storms that dumped huge amounts of rainfall over a short period of time with intense heat. Who knows what weather conditions are next this difficult year?

Unfortunately, floodwater contains bacteria and other harmful substances, so garden vegetables submerged by floodwaters should not be eaten. If fruit, including tomatoes or peppers, have never been submerged, then those are safe to harvest and eat. Flooding issues are one more reason I prefer growing vegetables in raised beds.

According to Purdue University experts, when in doubt, throw out food in the home that might have been damaged or spoiled in floods. Keep foods only if they are in undamaged commercial cans and sanitize the cans before using the food inside. To sanitize cans, remove the labels, mark the cans with indelible ink, and then wash the cans in a strong detergent solution. Then immerse the containers for 15 minutes in a solution of 2 teaspoons chlorine bleach and 1 quart of room-temperature water.

Be aware that rodents, snakes and other animals might have taken refuge in storm debris in and around your home.

Landscape trees vary in their response to flooding, especially after periods of drought. Actively growing trees and shrubs are much more sensitive to floods than dormant trees in the winter and spring. The damage from drought and flooding can show up later in the season.

Mature trees can handle flooding much better than younger ones. Some trees intolerant of flooding include cherry, Eastern white pine, sassafras, white and red oak, and hickory.

Flooding might cause direct damage to trees by changing soil conditions so that oxygen is not available in the root zone. Eastern white pine can be damaged by only 24 hours of flooded conditions. Flooding also can weaken trees, making them more susceptible to damage from insects and diseases.

Trees that are flood stressed exhibit a range of symptoms that can 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 following a flood.

Symptoms can progress and ultimately result in tree death over a period of several years or they might abate as the tree recovers. It is very difficult to link a flood to the cause of tree death years later.

Avoid planting flood-intolerant trees in flood-prone areas and consider using raised landscape and garden beds in areas that could be subject to flooding.

The Plant Medic, written by Ricky Kemery, appears every other week. Kemery retired as the extension educator for horticulture at the Allen County Purdue Extension Service. To send him a question, email trich@jg.net.