Controlling Disease

            Hi everybody. With all the rain we have been having the past few weeks many plants are starting to actually show signs of stress from too much water. Roses are especially vulnerable to disease when the leaves stay wet with frequent watering or rainfall.

One of the most common diseases that can stem from too much moisture is black leaf spot. If you begin to see tiny black spots on the leaves of your roses, your plants most likely have this disease. The infected leaves will eventually turn yellow and fall from the plant. You can help prevent the disease from spreading by only watering the plant from the ground level and trying to keep the leaves as dry as possible. Of course, this can be really difficult when our Florida’s great rain machine is in full gear. If this is the case, you can treat your roses with a product called Orthenex, which will help to control the disease.

Another problem you can encounter with roses, along with other plants such as gardenia and citrus, is powdery mildew. This disease is characterized by a black, powdery coating on the leaves of the plant. One way to help prevent this disease is to be sure you have enough space between the plants for good air circulation. You can help prevent the disease by using a commercial fungicide such as liquid copper or an equivalent. If your plants already have the disease, removal is a bit more involved. Since the black soot will not go away on its own, you actually have to remove it from the leaves by using a weak solution of ordinary dish soap and water. Spray the solution on the plants and wipe off or use the water pressure from your hose to try to remove the black soot. Once removed, you can then use your fungicide and disease control to help keep it away.

Many people do not like to use commercial chemicals to treat their plants. Here is homemade remedy to help control powdery mildew. Add two tablespoons of baking soda and one tablespoon of Murphy’s oil soap or dishwashing soap to a gallon of water. Spray the solution on your plants but do so in the evening or early morning while the sun is not beating down. You should reapply the solution after a heavy rain.

Another common pest that can really ruin your garden is aphids. These tiny critters suck important nutrients from your plants that eventually weaken and can then kill your plants. Here is a great natural remedy you can try. This tip was submitted by Rick Birch of Palm Bay. He had an extremely severe outbreak of aphids in his garden and tried all sorts of remedies without success. He then tried this simple homemade solution with great success. The recipe was suggested by Dan a local extension agent in Palm Bay. To make the mixture, simply mix 4 tablespoons of ordinary baby shampoo in a gallon of water. Simply spray the solution on the infected plants and your problem should be resolved. It is always best to do this in the evening to avoid the plants being burned by the sun. I would like to thank Rick for his contribution.

During the summer months a lot of people will plant periwinkle, also known as vinca, in place of impatiens, which do not do well in Florida’s summer heat. This is often a good alternative however, during periods of continued heavy rain, they are very prone to getting fungus. The disease can make the plant get brown and literally turn it into mush. During periods of rainy weather like we are having this summer, it is probably a good idea to avoid these plants as you will be replacing them frequently. Instead try some hardier varieties such as pentas or marigolds. Verbena and dianthus also make great summer plants.

That’s all for this week and I hope you found the content useful and entertaining. I will see you next week with more great garden information and tips.