Windowsill gardening - a few herbs and a little sunshine

To botanist Ellen Henke, the sunny kitchen windowsill that doesn't contain a few pots of herbs represents wasted gardening space and lost culinary opportunities. It takes minimal time, space, and effort to maintain an indoor herb garden, Dr. Henke explained in a telephone interview from her home in Saratoga, Calif. And the effort will provide the family chef with flavor-enhancing options that aren't always available from a jar.

``The transition from gardener to chef is made with a snip of the scissors or a pinch of the fingernails when the herb garden is just a few feet away,'' says Henke, who teaches and writes on horticultural topics.

Growing plants under a wide variety of conditions is second nature to Henke. But, she insists, ``even for the newcomer, growing herbs is not difficult.''

Besides a sunny window, the basic needs for indoor herb gardening are containers with bottom drainage holes, a package of all-purpose potting soil, another of perlite, and a few good-quality seeds. A few packages of unflavored gelatin will also help, Henke says.

While most herbs can be grown indoors, the more popular are chives, basil, parsley, and thyme. If you are trying indoor herb growing for the first time, you might start with these four. Henke suggests growing them in 4-inch-diameter plastic pots. Here are her directions:

1.Cover the drainage hole in the container with a coffee filter to stop the soil from washing out. To assist drainage, line the bottom with a layer of pebbles or plastic-foam ``peanuts'' used as a packing material.

2.Fill the container to within an inch of the rim with a mixture of one part potting soil and one part perlite, tapping the pot to settle the soil.

3.Sow three or four seeds in each container at the depth and spacing recommended on the package. Use a pencil or sharpened stick to make the holes for the seed. Slow-to-germinate parsley seeds can be hurried along somewhat if you soak them overnight before planting.

4.When the seeds are in place, gently smooth the soil over. Set the pots in a bowl of 1-inch-deep water. Leave them there until the top of the soil becomes moist.

5.After removing the pots from the water, label them carefully. Now take each pot separately and place it in a clear plastic bag. Seal the bag with a twist tie to form a miniature greenhouse. You won't have to water the pot again until the plant starts growing.

6.Place the bagged container where it will receive at least five hours of bright daylight, but do NOT place it directly in the sun, where it could easily overheat.

7.When tiny leaves have opened, remove the pot from the plastic bag and gradually move it to a sunny window. Herbs enjoy daytime temperatures in the low 70 degrees F. and prefer a drop of at least 10 degrees at night. Too much heat and too little light produce weak, spindly plants.

Henke says the surface soil in the pots can dry to a depth of about half an inch, but no more. For best results, keep the soil ``evenly moist.''

The phosphorous and potassium nutrients the herb plants will need throughout the winter will be in the potting soil. But nitrogen is another matter. This other major nutrient is quickly used up by growing plants. It also easily leaches out of well-watered soil. This is where the unflavored gelatin comes in.

Henke says to ``thoroughly dissolve 1 packet of gelatin in 1 cup of boiling water and then add 3 cups of cold water to make one quart of liquid.'' Soak the soil (not the plants) with this gelatin solution until the water begins to run out at the bottom.

One application ``will supply a young herb plant with enough nitrogen for up to four weeks,'' Henke says. Mature herb plants, which require less nitrogen than young seedlings, should be given the gelatin solution only when it is being heavily harvested.

Gelatin, which is a protein, is converted to nitrogen for plants by the action of soil bacteria. Because they work slowly but steadily, the gelatin becomes, in effect, a slow-release fertilizer. This is important for herbs, as quickly available nitrogen would produce a rush of green growth at the expense of concentrating the flavor-filled oils - which is the whole purpose of growing herbs in the first place. (Note: the gelatin must be unflavored. Flavored gelatins contain sugar, a carbon, which would tie up the nitrogen in the soil.)

If your indoor herb garden is producing more than you can use, dry the excess in the oven. Place cheesecloth on the oven rack and spread the leaves evenly over it. Set the oven on low and leave the door partly open. In a few minutes the leaves will be dry. Crumble and store in a sealed jar in a cool, dark cabinet.