Georgia’s weather is funny, and it does not take long for it to change on a dime. Spring was warm and wet and now we are hot and humid. Both weather conditions provide challenges, and that always keeps gardeners learning new things in the proverbial “classroom” of Mother Nature.
But for now we just need to deal with what is presented in front of us and try to make the best of it. With all the high humidity and rainfall, plant diseases are potentially on the rise.
Now this is not a call for alarm and panic. Most leaf spots in the landscape are not a real threat to the overall health of the plant. Just be aware that conditions are favorable for them and be on the lookout.
If you have leaf spots on some of your landscape plants, there are things you can do to keep the disease under control.
One of the basic concepts of gardening is to put the right plant in the right site.
If the plant will not grow and thrive because your landscape does not provide what it needs, then you are already stacking the deck against yourself. Before you buy new plants, be sure to know the growing requirements needed for the potentially new tenants of your landscape.
If you already have plants in the ground, make sure the growing conditions are as good as you can make them for the plant. Provide adequate mulch and optimize soil fertility by following soil test recommendations.
Make sure you allow for good air circulation so the plant does not stay wet any longer than need be. Many of the fungi that cause these leaf spot diseases will overwinter in the leaves that fall to the ground. Raking those up will reduce the amount of disease carried over from year to year.
In the vegetable garden, the same principles apply.
All spent plants should be removed entirely from the garden. This will help reduce the chances of the disease harboring in the soil from year to year.
Follow a three-year rotation with not only the same vegetable, but also vegetable family. One example of vegetables in the same family is tomatoes, peppers and Irish potatoes. All three vegetables are susceptible to the same diseases. After a couple of years of planting back to back tomatoes or potatoes then peppers, you need to switch to, for example, cucumbers, squash or beans in that part of the garden.
Make sure the soil in the garden has been tested so you are providing optimal conditions for plant growth. Incorporate plenty of organic matter to encourage rooting and water drainage.
Strong healthy plants are more resistant to stress from weather and disease pressure. Plants are a lot like us in that regard. Many times when you get sick, you have been stressed or tired and not quite on your game.
If you follow these guidelines severe outbreaks of foliar diseases will be kept to a minimum and the plant will be able to survive without too much trouble. There are plenty of fungicides available on the market, and sometimes they are simply needed. If you have any questions on which fungicide would be best for your problem, call me at the office and I will be glad to talk it over with you.
Michael Wheeler is county extension coordinator for the UGA Cooperative Extension office in Hall County. You can contact him at 770-535-8293, ugaextension.org/county-offices/hall.html. His column appears biweekly and on www.gainesvilletimes.com.