In case you have just woken up from an extended coma, let me inform you that we are having a very rainy year thus far. Over the last 30 years, Atlanta has averaged 49.7 inches of rain per year. Thus far in 2013 we have already accumulated 41.5 inches of rain. That’s a lot of rain. And we still have almost half a year still to go.
This excessive rain situation is a bit of an anomaly for us. We have become used to parched, cracked-earth gardening conditions. But too much rain can be as problematic as too little rain.
The major problem has to do with poor drainage and plants standing with “wet feet” in waterlogged soil. Believe it or not, you can actually drown a plant with too much water. The water saturates the soil and cuts off the supply of oxygen and nutrients to the roots. This is one major reason why garden experts have been encouraging the use of raised beds for many years. Raised beds allow excess water to efficiently drain away from plant root systems while still leaving plenty of residual moisture in the soil.
Excessively wet soil can also be the result of poor soil conditions, even if you are using raised beds. Soil with too much clay will tend to hold water like a sponge once it gets saturated by heavy rains. If you are gardening in clay soil that has not been amended with compost, organic matter or other soil conditioners, you will get soggy conditions that make it far more difficult to raise healthy, thriving plants of any sort. To combat these conditions, add lots of organic matter to your soil and turn it under into the first 6-8 inches when preparing your planting beds each year. You will be doing yourself and your plants a favor over the long haul with this approach, whether we have rain, drought or the ever-elusive ‘perfect’ weather conditions.
Other problems associated with wet soil include funguses (or should that be fungi?) and diseases that tend to arise in damp conditions. One example is Early Blight, a fungus which can kill off tomato plants. Powdery Mildew also thrives in wet conditions. You can treat many of these problems with organic treatments such as readily available Safer’s brand products.
A preventative consideration is to add mulch around plants. This helps reduce splashing around the base of plants. Splashing rain can actually spread existing diseases living dormant in the soil. Further, watering, especially overhead sprinkling, can leave wet leaves which become a host to common spore diseases. Try watering with soaker hoses or, if you must use overhead watering, do the watering in the morning hours so that the plants can dry out before the heat of the day.
You may also want to consider adding a light dressing of slow-release fertilizer to help compensate for nutrients that may have been leached out of the soil by the frequent rains. Milorganite, available at most garden centers, is an excellent slow release fertilizer that will not over-stimulate your plants and will last into the late summer months.
Finally, let me recommend good housekeeping practices in your garden. Trim away diseased or damaged growth from vegetable or flower plants. Pull up and discard plants that may have rotted due to the wet conditions. Don’t let fallen leaves or other plant debris to remain on the ground. Keep stems, fruit or branches from resting on the ground when possible. All of these steps can help prevent the outbreak of disease or simple rot from spreading through your garden patch. Also, be on the lookout for thriving weeds among your plants. The excessive rain water only encourages the little thugs to take root and to rob your plants of light and nutrients.
I will readily admit that I never thought I would write about these too-much-rain problems. We have had serious ongoing drought conditions for most of the last 20 years. I have learned the hard way how to cope with drought. About the only thing I can say I am pleased about with all this rain is my much reduced water bills. My last water bill was less than half of my usual bill for this time of year. I guess even all these cloudy days do have a silver lining after all.
Jeff Coghill has been gardening in DeKalb County for more than 30 years and has probably killed at least one of each kind of plant he has tried before getting another one to thrive. He is a gardening volunteer at the Dunwoody Nature Center and works closely with members of the DeKalb Master Gardeners group. He can be reached at firstname.lastname@example.org.