Watch for effects of June rains into summer
By DAVID SPRAGUE
OSU Ext. master gardener volunteer
I had just planted my vegetables, and set out new perennials and annuals when the rains started. So far the plants have survived and I hope yours have to, but it’s too soon to say everything will be alright.
The heavy June rains may cause problems in our gardens later on.
What are some of the ways the rains can affect our plants? Let’s take a look.
All plants need water, but too much water can be worse than too little water. Too much water stops root growth and inhibits nutrient uptake, especially nitrogen.
Plant roots need oxygen to survive, and in normal soil conditions the roots find this oxygen in tiny spaces in the soil called macropores. When the soil is wet, these tiny spaces fill with water, cutting off oxygen to the roots.
If the soil stays wet for too long, the roots can’t get the oxygen they need and they begin to die. In the garden this condition shows up as wilted or yellow leaves and stunted growth. Usually, once the soil dries out the plants recover. You can help them recover faster by giving them a little fertilizer.
Wet conditions make perfect incubators for fungal diseases, particular leaf spot diseases. Leaf spot diseases usually appear as dark-colored patches on the foliage. Leaf spot on ornamental plants is unsightly but usually does not harm the plant. On vegetable plants, leaf spot can reduce the yield.
Often leaf spot diseases can be controlled by pruning the plant to allow for light penetration and good air circulation into the plant. Removing any leaves with spots on them will slow down the spread of the disease.
For more serious leaf spot problems you can consider using a fungicide, but that is the last step after all other possible solutions have been tried. Before using a fungicide, the disease has to be diagnosed correctly. The OSU Extension office’s plant and pest clinic can help you with the diagnosis. Call 330-533-5538 from 9 a.m. to noon Wednesdays and Thursdays to talk to someone about your garden issues.
Root rot is another disease that can develop in wet soil. Root rot is a general term used to describe a disease where a pathogen, usually a fungus, attacks the root system of a plant.
Plants with root rot are often stunted or wilted, and may have yellow or discolored leaves. Unfortunately, once these symptoms are seen it is usually too late to save the plant. Select healthy plants from a reliable source and increase drainage in the area where you plant them.
For more on the effects of heavy rain, visit http://go.osu.edu/heavyrains.