Home Gardening

Problems come "pouring in" with wet weather
Mississippi Gardens Newspaper and Web Column - July 5, 2004

A friend of mine, who doesn't garden, was sure that our local watermelon crop was doing fine because of all the rain.  It seemed logical to him that all the rain would be great for watermelon.   We all know that too much of a good thing is not actually good at all.  Such is the case for too much rain on our Mississippi gardens.

Problems come pouring in (pardon the pun) to Extension Service offices when extended wet weather occurs.  It's really worse than drought, since diseases do not proliferate in dry weather.  And, when it's really dry it's also obvious what we need to do.  Under those circumstances we either have the capability to irrigate or we don't. However, when it rains every day there are at least three factors working against us.

When it rains and stays overcast for extended periods of time plants do not get as much sunlight as they need.  The reduced sunlight cuts down on the rate of photosynthesis, which is the plants way of turning raw materials into sugar.  The sugar serves as plant food and the building blocks for all sorts of plant products. Without adequate sunlight, garden plants may produce smaller fruits, roots and stems that may translate into lower yields and poor quality.

Excessive rainfall may also result in saturated soils.  At any given time, about half the space occupied by healthy, loose garden soil is pore space.  Within these microscopic channels plant roots find water and air.  When the soil becomes saturated with water, it pushes the air out.  In these low oxygen situations, plant roots begin to die.  Some plants can tolerated these waterlogged conditions better than others but the majority of common garden vegetables from asparagus to zucchini need well-drained soils.

Many deadly diseases thrive in wet conditions.  A typical soil-borne disease like Buckeye Rot of tomatoes is splashed onto tomatoes by rainfall.  Diseases that attack roots invade root tissue as it begins to breakdown in waterlogged conditions.   Foliar diseases reproduce and spread rapidly on leaves that rarely dry out.

What can be done to combat the three pronged attack brought on by monsoon conditions?  Since we know rainy seasons can occur, we should grow raised bed gardens.  Raising the planted area six to eight inches allows for better soil drainage. Incorporating organic matter can also help loosen heavy clay soils and improve drainage and aeration.

Choose vegetable varieties that are resistant to common diseases.  Don't crowd plants so they can make the most of available sunlight.  Use fungicides labeled for controlling vegetable diseases such as those containing the active ingredients chlorothalinil, mancozeb or maneb.

If your watermelons are suffering from too much of a good thing, just chalk it up to experience and start making plans for a fall garden and hope there are no late season hurricanes.  Happy gardening!