MARIGOLDS. Gold, yellow, or white - from China to America - they make happy, hardy border in every climate. GARDENING

One of the most popular, colorful, and easy-to-grow annuals for borders is a member of the calendula family - the pot marigold. Since the marigold thrives in many climates, no garden should be without this steady bloomer. In fact, it does very well in northern cooler weather, where flowers appear sturdy and bright in the cool spring, late summer, and early fall.

So it's still not too late to buy marigolds in pots and set them out. But next year sow seeds indoors before spring, and then transplant them outside as the weather becomes milder. Each seedling should be about two inches high.

The newer Pacific strain resists hot weather and blooms profusely even during the hot summer months. This strain boasts a full range of colors from apricot, lemon, and flame to persimmon and an unusual creamy white.

Ordinarily, most gardeners think of marigolds in the round form. But now horticulturists have given them a more exotic shape for garden variety.

Varieties to choose from

Here are a few of the special marigolds available today:

A bright orange, quilled-petal variety called Radar has made an appearance on the garden scene.

Another variety, with incurved petals similar to the Japanese chrysanthemum, named Geisha Girl, is a growing favorite.

A third is a crested species originating in Germany and perfected in the United States. This German variety comes in a mixture of colors, but each marigold has the same shape of guard petals flat around the outside with a crested center made up of tiny tubelike quills.

Most outdoor gardeners consider the marigold too odoriferous to use indoors. But what was once offensive to some nostrils has been muted in most instances and, in some, eliminated entirely.

The persistent research of David Burpee, of the seed company by that name, has done the most to turn this native American plant (originating from Mexico and the US Southwest) into an attractive popular flower.

Today the marigold is every bit suited to the indoor vase. The newer hybrids are particularly prolific bloom producers.

In the 1930s, Mr. Burpee acquired some special marigold seeds from China. Through his research he finally grew not only a magnificent golden blossom variety with no odor, but also produced a white marigold!

Choices of small marigolds, especially for borders, are Mexican or Signet marigolds, Yellow Gem, and Ursula (gold with orange eye). All raise a dainty flower on a seven-inch plant, with the flowers resembling miniature single marigolds.

Look for evening glow

If you have marigolds in your garden, I am sure you have noticed something spectacular. Large flowered and hedge marigolds have an unusual feature of ``evening glow'' that shows up any time daylight is waning, especially 20 minutes after sunset. Orange and yellow colors are most appealing. The All-American-rated marigolds especially have this brightening quality.

Lack of phosphorous causes stunting and results in foliage turning a maroon to bronze color. Spray the foliage with liquid fertilizer high in phosphorus or potassium. One application will green up the plants nicely in just a few days.

Sometimes plants form luxurious bushiness with no flowers. A high-nitrogen lawn fertilizer is the culprit. Flush the surrounding plant soil with water. Then apply liquid phosphorus and potassium.

Buds should start to reappear in two or three weeks. Golden Marigolds good sentinels

Besides offering an array of colors, one particular variety serves gardeners very well in warding off garden pests, as reported by the Agricultural Research Service, a division of the US Department of Agriculture.

The Golden Marigold, Tagetes minuta - a common South American variety - rids garden soil and crops of tiny parasitic worms called nematodes.

Gardeners plant this variety to keep the soil in good condition before they plant corn, tomatoes, beans, egg plants, and a number of other crops.

One can also continue a fringe of marigolds as sentinels around the garden border during the growing season and right on up to harvest. This will guard against any nematodes returning.

Whatever varieties you select for your garden, outdoors or indoors, the hardy but easy-to-grow marigold will brighten it with color all through the growing season. If you haven't yet, try marigolds - you'll like them.

Gardeners wishing to belong to the Marigold Society of America should write to PO 1776, Stillwell, IN 46351.