The vagaries of February have early gardeners wondering whether this weekend's customary pea-planting will go as scheduled. Others fear for bulbs that popped up before the blizzard of '83.

As far as developing bulbs are concerned -- relax. Tulips, daffodils, crocuses and snowdrops may seem to be pushing up all too soon, but they know what they're doing. When it gets too cold, or the snow is heavy, they just stop growing and resume their progress when things warm up again. If anything, the garden will be grateful for the snow's insulating properties. With a foot or two of the stuff on the ground, hard frosts won't hurt anything that's trying to grow.

On the pea front, there's no way of telling what will happen. When all this moisture melts, it's likely to make garden ground very soggy. While peas tolerate cold, moist soil, sopping conditions aren't likely to do them any good. Besides, you don't want to walk around in your garden when the ground is wet -- that soil can become badly packed down. If your garden is fairly well drained -- say, it's on a slight incline and most of the melting snow has run off it -- you can go ahead and plant peas. Make your bed next to a garden path so you don't have to walk on ground where you'll be planting later on.

If you want to get rot-resistant captan-treated pea seeds, they're readily available. I don't like chemically treated seeds; I prefer to risk losing the half-pound or so of seeds that I put in early. When you start this early, there's always time to put in another crop if something goes wrong with the first. In ten years of gardening, I've lost one pea-planting to rot.

A problem with peas, especially the space-saving pole varieties that I prefer, is that they get "leggy" -- the lower portion of each vine becomes dry and brittle, making the plant somewhat weak. I've never found that this affects production, but it does make for awkward handling if the plants fall over.

To solve the problem, I dig a trench about a foot deep -- for pole varieties -- where the peas are to be planted. I sow the seeds rather thickly, which helps them support each other, and cover them with three to four inches of soil, which I tamp down firmly. As the plants grow, I add soil to the base in stages; by the time they're producing, the trench is completely filled and the vines have developed sturdy stems. This also hastens production -- you may be picking peas a good week to 10 days before you expected to.

There's a huge variety of peas -- edible-podded and plain garden peas. Dwarf varieties, which grow to just 12 to 20 inches, don't need support. When planting, dig your trench about six inches. Mid-size varieties, 20 to 30 inches tall, can be planted in an eight-inch-deep trench and will require some support. An inexpensive and relatively easy support system can be made with sticks, twigs and branches broken into three-foot lengths and "planted" vertically in the ground down the middle of the trench. The thicker your stick "trellis," the sturdier your pea vines.

Pole peas are great for a small garden because they take up less ground space. However, since they grow to five feet or higher, they definitely need strong support. Chicken wire or garden trellis netting are well-suited for the job because they provide plenty of surface area for the pea-vine tendrils to grasp.

Netting, usually nylon, is available in a variety of heights and lengths from garden centers and through catalogues. It's inexpensive -- a five-foot by 25-foot roll from Burpee is less than $10. It doesn't last as long as chicken wire, which also offers more support, but chicken wire, available in feed stores and garden centers, is more expensive. In either case, I recommend at least five-foot heights -- I've seen sugar snaps droop over my six-foot chicken-wire trellis. PLANTS FROM AFRICA -- In the National Arboretum's Administration Building Auditorium this Friday at 1:30, there will be a lecture on plants from Africa, as part of the Living Legends series. Participants will learn the history of African violets, coffee, sesame and Atlas cedar, and see how we use them today. The Arboretum is at 3501 New York Avenue NE. Call 472-9279. THOSE BLOOMING BEGONIAS -- Bittersweet Hill Nurseries in Davidsonville is presenting a special Begonia-Orchid-Houseplant demonstration Saturday and Sunday from 9 to 5. Unusual houseplants such as the Star Jasmine and Orange Strepstolen will be sold, as well as blooming orchids and begonias. Door prizes awarded each day. Exit off the Beltway at U.S. 50 (Annapolis) and follow Route 424 (south) to the nursery. Call 301/798-0231.