It's amazing what one learns just by reading magazines and garden journals. The benefits of coffee grounds to the garden have been pretty well documnented. However, I had never realized that they had insecticidal properties, as well. One day I was captivated by an article in a scientific garden journal touting the insecticidal properties of coffee grounds. I read the article with a great deal of interest, for I am a coffee drinker, and every day some coffee grounds are generated as I indulge my love of the rich brown brew.
According to the article, coffee grounds have powerful insecticidal properties. When spread around the base of plants, they act as a systemic insecticide. The plant's roots are able to absorb the chemicals and transport them to the leaves. Azalea lace bugs, scale insects, and other insect pests dislike whatever substance is transported. I don't personally know if it kills them or repels them. All I know is that after two years of using coffee grounds around my azaleas, they are free of the disfiguring azalea lace bugs.
A similar miracle happened to my hollies and camellias. They were infested with scale insects. Using coffee grounds around the base of these plants significantly reduced the insect population, and they are healthier and more attractive as a result. My sago is looking much better, too, after having been treated to a coffee-ground mulch. Fairchild Tropical Gardens in Coral Gables FL, is using coffee grounds on all its Cycas species. Tom Broome, owner of Cycad Jungle in Lakeland, has had good results using coffee grounds around his cycads. Other gardeners report similar results.
I will never throw away a coffee ground or a tea bag again. Their benefit to the plants and to the soil has been adequately demonstrated to me and is worth the extra effort it takes to save them.
Tomato Woes and Kitchen Waste
For years I have earnestly tried to grow tomatoes. I yearn for them, and year after year I suffer disappointment. Not everybody understands the difficulty of growing tomatoes in sandy soil and hot, humid climates. First of all, the sandy soil is void of organic matter and nutrients. Secondly, it is infested with root-knot nematodes. The climate, too, promotes the growth of fungi and the pathogens such as verticillium wilt, early blight, gray leaf spot, and other diseases.
I know now why Daddy started a new garden area every few years for the home garden. Cutting down trees and clearing out a new garden area was hard work. It had to be done, though. After a few years of growing vegetables in the same area, diseases, insects, and pathogens infest the soil and affect the plants. After we cleared new ground and planted the garden in it, the vegetables grew with renewed vigor and productiveness. Daddy had good, Mississippi clay-based soil with a significant amount of organic matter to begin with. So he was already a step ahead of me and my Florida sand.
We in residential areas with small garden plots have less choice about where to place our gardens than Daddy did with his 240-acre plot. Much of my residential lot is planted with permanent landscape shrubs and trees. Then, there must be room for favorite annuals, perennials, and my large collection of container plants. The vegetable plot often gets the leftovers after all these are factored in.
This past year I tried growing tomatoes in containers. I had several large, recycling bins that I thought would be perfect. Alas, it was not to be. My plants grew to begin with, but their color was poor in spite of adequate fertilization, and the plants simply were not vigorous. The longer they grew, the more they declined. When I finally gave up and pulled them up, the roots were swollen and covered with galls. I knew that they were infested with root knot nematodes.
I practice crop rotation, making sure that other Solanaceae such as peppers and eggplant are not planted in the same place year after year. I had added compost to enrich the soil, and it has been properly solarized, as well. I have almost given up. However, I'm going to make one more concerted effort to grow tomatoes next year. I have a trick up my sleeve that I hope will make all the difference.
Determined to give it one last try, I'm throwing my whole arsenal of weapons at the tomato plagues. This summer I dug a hole about two feet deep and wide where I plan to plant my tomatoes next year. I piled the soil that I removed from the hole to one side. As my kitchen wastes accumulate, I put them in the hole. Included are all vegetable wastes, coffee and tea grounds, egg shells, and almost everything except meat or greasy foods. When a layer has accumulated, I cover it with a bit of the excavated soil, and then I start the process all over. Layer by layer, my hole fills up. At present, I have one hole completed, and the second is well on its way. I'll keep doing this until I have as many holes as I want for next year's tomatoes.
Next spring, after all the ingredients have "cooked" and become a part of the soil, I will plant my tomatoes. My fingers are crossed and my hopes are high that I will be able to grow some decent tomatoes next year. I will increase my chances, because no Solanaceae has ever grown in these holes. I will also select tomato varieties that are resistant to nematodes and pathogens.
The plan has been made and is being implemented. Now only time will tell. Other gardeners tout the benefits of this type of composting, so I don't see why it won't work for me and my tomatoes. I don't expect my efforts to be a total waste even if I don't grow tomatoes successfully next year. I will know that the soil is richer and that other plants will grow well in the improved soil. I will not have exploited the Canadian peat bogs, and I will have recycled my kitchen waste and used it for building my soil. That beats sending it to the landfill.