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buckwheat flower

A crop of buckwheat flowers in a field. Cover crops such as alfalfa, barley, buckwheat, clover, millet, mustard, oats, field peas, annual rye, sunflowers, turnips, vetch and wheat protect the soil surface and to add nutrients to soil. They also out compete weeds and loosen compact soil.

Q: What is a cover crop?

A: It is another name for green manure. Cover crops overlay bare ground after vegetables are harvested, to protect the soil surface and to add nutrients. Suitable seeds to plant as a cover crop are ones which grow quickly and outcompete weeds. Another virtue of cover crops is that their roots will loosen compacted soil. If left in the ground over winter—which often is the case—a cover crop also will protect the soil surface from erosion.

Plants commonly used as cover crops include alfalfa, barley, buckwheat, clover, millet, mustard, oats, field peas, annual rye, sunflowers, turnips, vetch and wheat.

I seldom plant cover crops because I do no-till gardening. It takes a long time for the untilled residue of a cover crop to decay. If I were to try the system in my garden, I would cut the plants down with a string trimmer when they were a few inches tall, then leave them as mulch, to decay over the winter.

Q: Why is my watermelon making only male flowers?

A: Typically, melons, cucumbers, and squash make only male flowers at first. Presumably the plants are trying to develop a ready supply of pollen—which is made by male flowers—so that bees will be coming around to get pollen when the first female flower opens. Then, as the bees travel from flower to flower, they transfer pollen to female flowers. Presto! Melons, cucumbers and squash start to grow as soon as the pollen is taken inside the female flowers.

After a round or two of making male flowers, those plants start to make both males and females. Female flowers always can be distinguished because they have a baby fruit at the base. Once the flower is pollinated, the fruit starts to grow.

Although the plants always make more male than female flowers, sometimes they try to start too many fruits. This is not a problem with cucumbers and summer squash; however, big fruits may need to be thinned. This is especially true for melons, pumpkins, and some winter squash. And it is especially true in our short season of warm weather. If a plant tries to grow too many fruits, none of them can ripen before fall frosts kill the plant. One way to help the ripening process is to see that the plant grows only one fruit on each branch. Clip off others as they start to grow.

If your watermelon is still making only male flowers by Labor Day, it will not have time to ripen any melon which might come along. When you try next year, give the melon plant a head start by sprouting the seeds in the house, where it is warm. Start only a month before you can put the plant outdoors. It the roots get cramped, their growth will slow down. To plant even earlier, transplant from a small to a big pot as soon as roots touch the bottom; then grow the melon plant in the big pot until the nights are warm enough for it to live outdoors.

Once the melon plant is in the garden, keep it as warm as possible. I surround heat-loving plants with a cold frame. I keep the cold frame in place all summer, removing the top when hot days arrive. Warming the soil, making sure that the plant has full sun, blocking the wind, and covering the plant on any cool night will help it grow faster.

Watermelons are really hard to grow in our short seasons. Next year look for small melons, which have a better chance than big ones. Also look on the seed packet for "days to maturity." Ones with a number less than 90 have a better chance.

Q: What can I put in the compost pile and what doesn't belong there?

A: Put in any kind of plant except ones with diseases. The disease organisms might not die in the compost pile. Plants with seeds are harmless unless they are weed seeds. In other words, weeds make good compost unless they have flowered and made seeds, which could live to spread the weeds wherever the compost was spread. Be sure to mix fresh green plants with dead brown ones.

When you think about green and brown, think that green includes all colors of flowers, and all colors of fruits and vegetables from the kitchen garbage bucket. Brown includes white paper, newspaper, and cardboard as well as brown plant leaves and stems. I have read various formulas for the proper proportions of green and brown, but I honestly do not attempt any measurement. When I notice that I can see only green stuff on the top of the pile, I throw in some brown stuff.

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Do not put any pieces of animal origin in the pile—no meat, fish, or cheese. There are two reasons for this. One is that they smell bad while they are decaying, while decaying vegetable matter has a pleasant smell. The other is that meat, fish, and cheese would be appetizing to many small animals which would raid your pile and scatter its remains. The exception to the rule of no animal products is eggshells. They are a source of calcium and a valuable piece of coarse texture in soil. They do not smell bad and are not carried off to be some animal's lunch.

Q: Summer is really over, but my onion tops still are not falling down. Should I dig them to dry or wait?

A: Wait as long as you can without having the onion bulbs freeze. When the tops fall, the onion is mature and will store for the maximum time. Immature onions taste the same, but they soon spoil in storage. If you must dig immature onions, dry them in the same way as always. Eat them first, mature ones later.

Next year you might want to check the "days to maturity" of onion seeds before choosing the variety to plant. Large onion varieties will vary from 90 to 125 days. By contrast, varieties grown for green onions or pearl onions will need 60 to 80 days. When choosing an onion type, do not grow any that are labeled as short day onions. They are successful only in southern states.


"I take a very sanguine view of neglect. The small lawn in my neglected back garden is also neglected. In April it turns yellow with dandelions, in May white and yellow with daisies; half of it is green only because of the moss and in the autumn random fungi make guest appearances. Twenty-five years ago, in a fit of tidiness that shames me to this day, I applied weed and moss killer plus some fertilizer. The lawn became green, lush and profoundly boring. It took fifteen years to recover from my misguided attention. I had gone from neglect to over-management; now I mow it with more regularity than before, dig up the odd dandelion that seems to be too pleased with itself, and feel it is just right."

John Wright, A Natural History of the Hedgerow