With summer almost over, this is the perfect weekend to move house plants indoors and to begin preparing some of this year's summer flowers for fall enjoyment indoors. Of course, there are pitfalls to be avoided, but after your enviable track record of rebuilding the lawn over the past eight weeks, this weekend assignment should be simple.

The pending move of weeping fig, dracaena, schefflera, palms and other plants should not come as a surprise. Since late August, you've had capsule reminders to douse your plants with Safer's insecticidal soap, spraying foliage and branches liberally to get rid of spider mites, mealybugs, whiteflies, aphids and earwigs. If you've sprayed three times up to now, all it takes is one final spray this weekend and you're ready to move plants indoors.

If you have not been spraying in recent weeks, start now. But delay moving the plants indoors for another week or two until you've resolved any problems.

Here's how to spray and prepare for the move if you're just getting started:

Inspect all plants for problems. Junk any sick plant. If leaves have discolored slightly, prune them. If you must remove half the leaves on a plant because of disease, it's best to discard the plant and spare healthy house plants from inheriting the problem. Pinch flowers, too, because their days are numbered. Only perfect plants are candidates for transfer indoors.

If you only have a few plants to be moved, get the eight-ounce, ready-to-use Safer's insecticidal soap; if you have a lot of plants, use the eight-ounce concentrate and apply with a hand-pump sprayer.

Group your plants in a sheltered, shady spot outdoors, then spray generously. Spray tops and bottoms of foliage, or insects may survive. Plants should be dripping wet when you're through. Rather than return plants to their prior locations, move them to a sheltered spot next to the house. Repeat spraying of the insecticidal soap over the next two weekends, then move plants indoors the first weekend of October.

Remembering the last two years when we had mild temperatures in October, many plant lovers will resist moving plants indoors while good weather continues. The thinking is that plants will do better outdoors than in the artificial environment of the house. Actually, the opposite is true. Cool nighttime temperatures cause leaves to cease making chlorophyll. Once the process is started, many leaves grown over the summer will lose their color. Moving the plant inside won't save the leaves.

Hanging basket plants (such as fuchsia or scented geranium) are valid exceptions to the rule. These plants can stay outdoors until mid-October, but should be sprayed weekly for insects and moved indoors when overnight temperatures drop to the low 40s.

Incidentally, the fuchsia is showing its last round of flowers for the year. Fuchsias produce flower buds only when days are longer than nights. With the arrival of fall next Wednesday night, day and night will be of equal length; afterward, days grow shorter while the nights lengthen. Fuchsia flowers will linger into early October, at which time blossoms should be pruned away and the plant moved indoors before being allowed to go dormant for the winter.

If you are moving plants indoors this weekend, try to improve the environment immediately. Open windows to allow humidity to enter the house, especially rooms where plants are to be located. Ideally, you would quarantine plants in one room for a week or more to make sure there are no problems, but with your careful inspection and repeated spraying of insecticidal soap, chances are your plants will be clean. So move plants to rooms with strong, indirect sunlight, but do not place them in drafts near windows.

Cut back severely on the watering cycle, no matter how thirsty plants may have been outdoors. Revert to the spring watering regimen. Plants needing lightly moist soil will now be watered every seven or eight days instead of every third day outdoors. Plants that were watered once a week outdoors will revert to watering every other week. If you don't alter your watering schedule, you could have extensive leaf drop over the next 14 days.

Stop fertilizing now. There are some exceptions (African violet, holiday cactus, poinsettia, cyclamen, schefflera), but most plants will not require plant food for the rest of the year. Future columns will provide capsule summaries on fall-winter care for many of the plants you're shepherding indoors.

A word of caution to owners of weeping fig trees (ficus benjamina). You must provide the strongest direct sunlight possible when moving the tree indoors. The rule is that indoor light must be stronger than the light it had outdoors. Move the tree close to a window with a southern exposure, drawing the curtains or blinds so that maximum light hits the plant. This way, not one leaf will drop from the weeping fig. If you move the plant to a location where there is reduced light, every leaf will drop off in the next four to six weeks. Also revert to the spring schedule of watering the soil every two weeks. Watering more often will cause a massive dropping of foliage, too.

Turning to the bedding garden, squirrel away some of your flowering plants now while time is on your side. Geraniums will be lifted from the garden next weekend and saved for next year, but you should start saving coleus, impatiens and wax begonia this weekend. No, you're not losing plants, you're saving them for companionship over the winter. Here's how:

Check plants to make sure they're healthy, foliage is of good color and there are no signs of disease. Spray plants liberally with insecticidal soap, then wait an hour and spade the plant from the soil. Try to keep the clump intact, retaining as many roots as possible; if roots are massive, root prune before transfering the clump (soil and all) to a large plastic pot (12-14 inches) with drainage holes. Water immediately, let it drain, but keep the potted plant outdoors in a protected spot for the next two weeks. Water daily with lukewarm water (it must exit the base of the pot). Next weekend, spray with insecticidal soap again, and spray for a final time on the Oct. 3-4 weekend when the plants are moved indoors. The Oct. 3 column will update the care program.

Other chores and problems worth noting and tackling this weekend:

Fertilize your lawn again (the second September feeding). If you have old lawn fertilizer on hand, use it now according to label instructions. If you must buy fertilizer, make it 10-6-4 inorganic, applied at five pounds for each 1,000 square feet of lawn. Use spreader setting 4 3/4 on the rotary Cyclone or Spyker spreader, 5 1/4 on the Scott drop spreader. If no rain is in the offing, take out the sprinkler and soak the lawn.

If you overseeded with fescue or ryegrass in late August, you'll probably be cutting the new grass next week, perhaps this weekend. To avoid any mistakes, remember to cut high and bag the clippings. Your rotary mower has a maximum cut of 3 inches, so use this for trimming your lawn for the fall. To minimize tip browning of the new turfgrass, cut back on the engine speed so the rotary blade doesn't mash the blade ends as it cuts. A new mower blade will give you the finest cut possible.

Expect to find the first boxelder bugs swarming around boxelder maple trees in the next week. Eggs are being laid on the maple, after which the annual assault on neighboring homes begins. If you stocked up on citronella oil in June and July, you're ready for them. Jack Eden hosts "Over the Garden Fence" Sundays from 10 a.m. to 1 p.m. on WTOP Radio (1500 AM).