Evidence is mounting that widespread use of supposedly "safe" chemical pesticides may lie at the root of the problems currently being experienced by beekeepers. One report can be found here. The study mentioned in this report found that feeding bees artificial nectar spiked with the neonicotinid insecticide imidocloprid in tiny amounts resulted in bee behavior like that associated with colony collapse disorder. While the maker of the insecticide, Bayer, debunks the study, I cannot help but wonder if we are ingesting this pesticide any time we consume a product containing high fructose corn syrup (HFCS). Traces of imidocloprid can be found in commercial HFCS, according to the author of the study. Therefore, it is definitely "out there" in the environment. 

Neonicotinid pesticides mimic the nicotine found in tobacco, a natural pesticide that affects a great many types of insects. Nicotine is particularly effective against the caterpillars of moths and butterflies, several of which feed on tobacco, tomatoes, potatoes and related crops. An anecdote from my garden a few years ago serves to demonstrate how effective nicotine is. During one particularly bad season for tomatoes, we inadvertently allowed a number of flowering tobacco plants (Nicotiana sylvestris) to grow too near the tomato patch. The sweet scented blooms of the tobacco attracted hornworm moths that laid eggs on both the tobacco and the tomatoes. The caterpillars started munching both types of plants, but those on the tobacco became stunted and died when they were about and inch and a half long, too small to do severe damage to the foliage. Those on the tomatoes, however, thrived, growing much larger and doing considerable damage before we could discover and remove them by hand. 

One wonders, therefore, if the severe decline in butterfly abundance, observable to anyone who takes an interest in butterflies from one year to the next, might also be a result of chemicals in the environment. A decade-old report found, for example, that pollen from corn genetically engineered to contain a pest-killing substance was harmful to monarch butterflies. How many other products that are commonly applied to lawns, flowerbeds and farms contribute similar effects? No one knows. But everyone agrees that butterfly populations are declining, and last March, this report appeared, suggesting that glyphosate, the active ingredient in herbicides such as Roundup, is seriously affecting monarchs and is turning up in humans, too.

There are a limited number of circumstances under which a home gardener might have to resort to chemical pesticide use. Situations involving noxious weeds already established on the property and ineracdicable by hand cultivation can be handled by spot treatment with glyphosate or triclopyr. Otherwise, I cannot think of a good excuse to use either herbicide. 

I can think of NO circumstance under which I would resort to a chemical insecticide, with the possible exception of a termite infestation of my house. And then I would have the treatment done by a professional. In the garden, we have learned that proper husbandry and integrated pest management techniques suffice to protect our vegetable crops, and we only grow ornamental plants that are typically pest-free in our region when properly sited and maintained. Many of our plants are native to the southern Appalachians and have natural resistance to pests and disease.

All home gardeners should follow similar guidelines. Chemical pesticides are both expensive and harmful to wildlife.

I'll say up front that we love our walk-in cold frames. Winter gardening will just never be the same again. But in our Tennessee Valley climate, especially with the unusually warm weather this past March, they do have one big drawback. They get much too warm for good results with Brassicas. We have tried various methods to produce spring crops of broccoli, cauliflower and cabbage without having to resort to almost daily sprayings with Dipel to keep the cabbage butterfly larvae from ruining them. We were hoping that the cold frames, which physically prevent the butterfly from reaching the plants to lay its eggs, were the answer. Alas, no. Even with all the windows open, the temperature climbs into the upper 80s on sunny days. We may get some decent cabbage, but broccoli and cauliflower would not tolerate the heat. So instead of Brassicas, we have planted some early beans, and we will soon be replacing the cabbage with squash and cucumbers. We plan to try some fall-planted Brassicas, so the plants will be maturing during cooler weather in November and December. In the meantime, we may figure out some way to ventilate the cold frames better, while still screening out the cabbage butterfly. Stay tuned.

Recycle Beer Cartons as Weed Blocker

If you are planning on building a new raised bed and wondering how to deal with existing sod or weeds, you may have considered placing a weed blocker fabric over the undesired plants. This works great, and you can build a bed right on top, but there is a free alternative: beer cartons. Those trapezoidal-shaped twelve-packs that bottled beer comes in make great weed blocker. Separate the cardboard at the glue seams and fold the container out flat. You will see that the flattened cardboard pieces can be interlocked, owing to the way they are die cut. A single layer of these interlocked pieces stops even tough weeds like poke and dandelions. Hold the cardboard in place with a rock here and there, and then simply place your soil mixture on top. Or, if you are enclosing the bed in a frame, just set the frame on the cardboard and fill it with growing medium. It takes about 18 months for the cardboard to break down, which is plenty of time to eliminate all the weeds under the raised bed. Weedblock fabric, by contrast, does not break down at all. And it does not come packaged with a frosty beverage.

You can also use newspaper and corrugated cardboard cartons for the same purpose. Gardeners have asked me about the potential harm from dyes and inks in these paper products. In my experience, the pigments appear to break down in the soil along with the cardboard, and in any event the amounts are minuscule in comparison to the volume of soil. Further, just because a substance is present, there is no reason to expect it to be absorbed by plants. If concerns remain, grow annual flowers on the site, then cut and discard them at the end of the season. This and rainfall should be sufficient to remove any soluble substance that might be associated with the cardboard.

I have always thought of April as the best month for lettuce in the garden, and this year is no exception. We started some plants in January and transplanted them to one of the greenhouses. The resulting bed, shown at right, has been yielding delicious salads for a couple of weeks now. Lettuce is super-easy to grow, so we plant a lot more than we can use. This allows us to go out to the garden right before dinner and pick individual leaves for a perfect salad. It helps to have a lot of plants to select from. If you only take one leaf per plant, the plant hardly notices. They just keep on growing, providing a continuously available supply of tasty leaves. It is much easier to clean lettuce when harvested as individual leaves, rather than cutting the whole head. I try to select leaves that are not too close to the ground, avoiding both sand and insects. Slugs like to hide near the soil line, too. Further, removing a leaf here and a leaf there helps maintain the decorative look of the bed. Lettuce is one of the prettiest vegetables, and can be used to border a flower bed, for example. The two varieties in the picture are 'Red Sails' and 'Oakleaf.' Seeds for both came from Mayo's here in Knoxville. They look great together in the garden and on the plate.

We started more lettuce on March 10. Those seedlings are now ready to be transplanted, which will take place this weekend. These plants will go into a raised bed without added protection, since the weather has warmed up enough that a hard freeze is unlikely. (I should not have written that. Now I have jinxed the whole Valley.)

The varieties we chose for the second planting are 'Red Romaine', 'Freckles', 'Michelle', 'Rougette de Montpelier', and 'Deer Tongue.' Unfortunately, we had spotty germination, a common problem when seed for some varieties is stored for more than one season. Seeds either fail to germinate altogether, or the seedlings are deformed and sickly. I have learned that old-fashioned cultivars such as 'Black Seeded Simpson' and 'Buttercrunch' produce seed that retains viability longer than some of the newer ones. The diversity of leaf shape and color combinations in lettuces is enormous, another reason the plants can be used decoratively. And during April in East Tennessee, they all flourish. If I had to grow only one spring vegetable, it would be lettuce.

Gardeners new to vegetable gardening should bear in mind that lettuce seeds require light to germinate. One of the main reasons for germination failure is covering them too deeply. This is particularly true of lettuces with white seeds. I usually just scratch the surface of the growing medium and scatter the seeds on top. Then I water them in and place them under strong fluorescent lighting. Seedlings typically appear within 48 hours. As soon as they have true leaves, thin the seedlings so they are separated by about two inches each way. If starting in cell trays, thin to one per cell. Feed lightly with soluble fertilizer and keep them as close to the lights as possible. They will be ready to transplant in 30 days. Before doing so, harden them off for a few days by gradually exposing them to outdoor conditions. I move my plants to dappled shade for a while, and I leave them out at night if the temperature is not predicted to go below 40. Once they are hardened off, lettuce plants will tolerate a light frost. Transplant them to a spot in full sun, in rich, well-drained garden soil. Most will be ready to pick after two to three weeks of growth outdoors.

Lettuce is also an ideal plant for container growing. Five plants can be accommodated in a pot 12 inches in diameter. Put one plant in the center and surround it with the other four, evenly spaced. Make sure to keep the soil in the container evenly moist.