Newsletter - July 2009

Hi,

I really haven't been lazy, just forgetful. I really though I'd written about organic pest control last month, but no. Instead I was in Portland doing family stuff, so I'll discuss it now. Its very popular to become "greener" and these activities are especially emphasized within a garden setting. However, there are misunderstandings and lots of confusion about the subject.

Every commercial product sold that is poisonous is labeled according to its toxicity. These certainly include insecticides, herbicides, fungicides, miticides (mites and spiders) and rodenticides (rats and mice), but also household cleaning products. People freak about having a pesticide in their garden shed yet will have far more toxic items under their kitchen sink. The problem is that people aren't taught to recognize the code words concerning toxicity.

Most of us understand that a skull and crossbones on an old medicine bottle label means poison, but currently, the label should also include the word "Danger". This means a Category I poison that only requires a very small amount, a teaspoon or less, to be lethal. A Category II poison uses the code word "Warning" and the Category III uses "Caution". All of these labels must also say "Keep out of Reach of Children" and this statement is all that's required on a Category IV Poison. A healthy adult could probably drink a full glass of Category IV without damage, but who would? So my laundry bleach is labeled "Danger", my air freshener is labeled "Warning", but for the garden I won't use anything labeled over a "Caution" and then only if I'm absolutely convinced I have no choice. I would rather choose to take care of a problem with a Category IV, or with a recommended natural product that's proven effective.

Three of the most poisonous compounds that I know of are found in nature. Arsenic used in rat poison is found in the soil. Nicotine, Castor Bean and Oleander are lovely garden plants and sea salt is readily found in everyone's kitchen. Even though when I was a child, nicotine was still recommended for insects that bite and chew foliage, this practice is now highly discouraged, especially for vegetable and fruit plants. If you want to make a tea, use chili pepper flakes. Its fiery taste discourages grasshoppers, cucumber beetles, budworms and caterpillars. The tea disappears quickly, so it won't hurt you when you bite into that first tomato. Diatomaceous earth (crushed fossils) is great to discourage slugs and snails. If you're battling aphids, use dish-soap in water and spray daily. To really control aphids you must deter the ants. If the aphids are on your roses or citrus, try slathering the base of the plants with petroleum jelly. This also keeps ants out of the hummingbird feeders and discourages them from entering cracks on your home's foundation. It's also cheap.

Another trick is to patiently wait for the bad insects to attract the good ones. I've heard it takes about two weeks, so this method works better on ornamentals than produce. The gardener though must learn which insects should be encouraged. Everyone recognizes lady bugs, but I've had to stop people from killing these insects in their homely, larval stage. Preying mantis, dragonfly, damselfly, certain tiny wasps, beetles and lace wing are all friends in the garden. I've read that spiders kill 90% of all bad garden insects. Plus they feed the birds, so leave them alone. Sometimes, when a problem is really out of hand, drastic measures must be used. I had a terrible whitefly problem about ten years ago. It had been building for about two years and I discovered that their favorite place in my garden was the undersides of my Elephant Ear foliage (Alocasia spp.). The whitefly was also on my fuchsias and green beans. I had tried a mild chemical spray, but the insect just laughed and continued to reproduce. I finally removed the host plant and the following year, no whitefly. I'm still leery about another elephant ear though.

The other organic gardening concern for most gardeners is fertilizing. We've all read about the thousands of acres taken out of production because of over fertilization. Fortunately, that's usually not a problem in the home garden. Most of us don't have the time and inclination to fertilize diligently to maximize a plant's output and wear out the soil. I know about all the nutrients plants need, but I usually don't add anything other than the initial soil amendments at planting and a feeding mid-season, unless I see a problem. Here are a few things to watch for. If a plant is turning yellow from the top down, it needs nitrogen. If it is yellowing from the bottom up, it is receiving too much water. If the plant has yellow leaves with green veins, it needs iron. These are the three most typical nutrition problems in our area, but every nursery person has seen other problems attributed by gardeners to either an evil insect, or a nutritional need, so… If plant leaves are brown and curling, its wind damage. If the leaves have big white spots, it has sun damage. If the plant is thin and rangy, it's in too much shade. If the plant is grey, it's gasping from thirst. If the leaves are speckled and it isn't insect, fungal or bacterial damage, it probably is suffering from a chemical burn.

The real gardener watches his plants as a mother does her children and instinctively knows when they need assistance. The rest of us are too busy and learn the hard way, usually after the plant expires. So read labels and remember that if you've exhausted all benign and organic methods to cure a garden problem, always choose the least toxic product to minimize affecting the environment. And I'll do better about writing on time next month.