THE BEST way to manage pansies is from seed-started flats, transplanted once, and set outdoors in October, but I notice many gardeners never get around to that, and there is a simple alternative.

You simply buy the young plants in October and set them along walks or in borders or beds where they are to bloom.

It is too bad for the gardener to wait until April, then set out to buy pansy plants. Good plants are often hard to find then, and in any case they are much more expensive than in October, simply because the grower has had to manage them all winter.

The past two years we have had midsummer temperatures in April - in the 90s - and cool-weather flowers like pansies can hardly be expected to do their best when faced with the shock of transplanting plus heat.

But planted outdoors this month, the tiny plants perhaps with five small leaves settle in immediately grow through the fall and winter and burst into flower in March, continuing to the Fourth of July or later.

A great advantage of October planting is that the pansies are ready for the mild days of early spring and bloom then, instead of having to use those wonderful days for growing.

What it boils down to is that fall planting produces pansy flowers with the daffodils, whereas spring planting means the flowers do not get going until the iris season. This is a six of seven-week difference, and it is a shame to lose those weeks of steady flower - and the best weeks of the year as far as pansies are concerned - merely because the gardener waited until spring to set plants out.

Now that we are convinced of the extra weeks of flower (and the larger size and greater profusion of bloom) from fall planting, the question arises exactly how to get going.

I buy pansies in boxes of 50 at a garden shop. You can get them all one color, or mixed colors.

The best, in my view, is the solid chrome-yellow one widely sold in Washington, usually simply called "yellow" which is large, long-stemmed, fragrant and flawless in the clarity and richness of color. It is solid, without a blotch or marking.

But for many gardeners the delight of pansies is their blotches and markings, and if you buy a box labeled "mixed," you will get garnet blotched with black; yellow marked with maroon, and the usual variety of patterns in various colors, so that the effect is rich and in five minutes the gardener can pick a bunch to marvel at.

One year I got equal quantities of yellow and mixed pansies, and alternated them in a bed.

A common error, the first time one plants pansies in the fall, is to underestimate their eventual size. In good soil I allow 12 inches in every direction between plants. By the time the irises bloom in May, there will be a solid mass of bloom.

In poorer soil (but there is no reason to grow pansies in poorer soil) you should space them more closely, but no closer than six inches apart.

The tiny plants will look rather lonely, but have faith. They will not only grow, but many bloom in mid spells during the winter. How much winter blooming there is depends partly on the strain of seed used to produce the plants (some are better for cool weather than others) and partly on how good the soil is.

If you think of the sort of soil and site where you would grow roses, tomatoes, irises or dahlias, you will not go wrong with pansies. They like the soil to be well dug and rich. I like to give each plant a small handful of manure as a surface dressing after planting - sprinkled an inch or so from the stem and very lightly scratched in. The winter rains manage the rest.

As tiny plants, 50 or so to a box, pansies should be planted out promptly. If you are going to keep them in the box several days before planting, be sure they do not dry out, but also be very sure they have air. If kept in a room and watered, they are almost certain to rot off at the ground.

A shady place outdoors or on a back porch is good, until they can be planted.

When you do plant them, water the boxes well, let them drain a few minutes, and gently separate the plants. Take out five or six together; this will be a mass about the size of a golf ball, leaving the rest in the box until, bit by bit, you are ready to set the small plants in the earth.

This is elementary, but I mention it because many gardeners lose their plants either from not giving them enough air and keeping them a week, or by dumping the whole boxful of plants out and taking a whole afternoon to get them in.

Another common error is to plant two young plants together, because they seem smaller than the rest. No. However tiny, plant each one separately. It will grow, and if you do not think it will grow, there is no point planting anything to begin with.

As each plant is set outdoors, firm the soil around it. A gentle pressure with three fingers will do it, just as you push a cork into a wide-necked jar. Do not ram.

Then water. Two eight-ounce cups per plant should do it. Do this within a few minutes of planting. There is nothing else to do except to keep an eye on chickweed or other pests that have a great way of sprouting in December when you are not looking. A light scratching will get rid of them.

In winters of exceptional severity, you may lose a few plants - I lost a third of them last year. Usually they come through without fuss, even if not mulched. Even if you lose some, enough will remain to make quite a show.

The March and April blooms usually are the largest. As the season goes along, the flowers get smaller, but more profuse and longer stemmed.