While latecomers are working feverishly to catch up with the fall lawn program, others are savoring the fruits of their summer labors. Seed applied the last weekend of August has sprouted and the emerging blades join an existing lawn that has greened up spectacularly thanks to last week's fertilization and continued watering. Should you stop watering? Probably not.

By garden standards, this weekend is likely to be a vacation of sorts. Miniscule jobs await you, but nothing tedious: the last spray of Cygon to azaleas for lacebug control if you didn't spray in the last week, a dousing of Safer's insecticidal soap to house plants that will be moved indoors next weekend, moving schefflera, rubber tree, sprawling palms and weeping figs indoors today so scale eggs aren't laid on branches next week, soaking spring-flowering shrubs so you enjoy optimum flowers next year.

However, if you prefer constructive gardening, play the detective's role and inspect the landscape for problems that have surfaced over the summer.

Have shrubs been victimized by disease and insects while you were away on vacation? Has the landscape changed substantially in recent years to the point that once-upon-a-time sunny spots are now almost totally in shade? Have you altered your landscaping to compensate for this.

Thankfully, plants are more forgiving than people. An azalea already in total afternoon shade won't rebel if an overhead maple restricts morning sun. The same may be said of rhododendron, laurel, forsythia and juniper, just to name a few. But roses will tell you in no uncertain terms that things have passed the point of no return. Declining roses simplify your decision: Prune the limbs shading the roses over the winter or transplant the roses in late March-early April. If you don't, you've grown your last rose.

If your landscape is in need of reconstruction or repair, don't postpone the work. You can't launch a transplanting program now (aside from cuttings that have rooted over the summer, or moving peonies to sunnier locations), but you can improve the landscape through the addition of new shrubs and trees.

How to fill a void in the landscape without spending oceans of money is not the problem some homeowners make it out to be.

On the one hand, you could call the American Society of Landscape Architects in Washington for their local membership list, then choose a professional to design the landscape you've always wanted; their blueprint literally orchestrates the garden, but you will have to contract for purchase and installation of the trees, shrubs and auxiliary plants.

Secondly, you can always steal some ideas from the Joneses in the next neighborhood or development who engaged a landscape architect to create their oasis. Photograph the landscape, then ask the garden shop manager to identify the enviable plants in the Jones' landscape; be sure you know the other parameters about growing the plants successfully in your garden.

The last alternative is the approach most homeowners use. Begin by taking clear color snapshots of the area to be landscaped, front and rear. Make notes about exposure, sunlight/shade conditions and the time of day, and a sketch showing distances from the house, garage and other plants. Call the garden shop manager and make an appointment; his recommendations are as close to the gospel as you will get. Once the choices are known, ask him to choose the hardiest nursery stock available.

Even before the plants come home, have a timetable for planting. If you're not planting right away, keep the plants in full sun, but hose them down twice-a-day, soaking the container or roots thoroughly. Piling mulch around and over balled-and-burlapped plants is suggested because it reduces moisture loss.

The best advice is to presoak the area for much of the day before planting; when you dig the next day, the work will go smoothly.

Hole dimensions seldom vary from the norm. Measure the width of the pot or rootball and dig the hole twice the width. Depth is usually 1 1/2 times the depth of the pot or rootball.

Remove all soil from the hole, then put down a four-or-five-inch layer of builder's sand at the base, followed by a half-and-half mixture of sharp sand and peat humus. At this point, stand the plant in the hole to see where it rests; ideally, the top of the rootball or the soil at the top of the pot should be in the top inch of the hole. Add or subtract soil (sand and peat humus) to get to this point, then plant.

With containers, turn the plant on its side, giving two hard raps to the base of the pot with your fist, and the plant will come out intact.

With balled-and-burlapped nursery stock, set the plant in the hole, then cut and remove the cord tying the burlap to the trunk. If you wish, use a scissor to slice some of the burlap at the sides.

Backfill with the same sand-and-peat mix over the top of the plant, then create a raised dike of soil to encircle the trunk about two feet away, and flood the dike with water. Add more soil as needed. Soak the plant at least twice a week up to the early days of December.

Because your sand-peat humus mixture is acidic (pH of 3.5 to 4), ask the garden shop manager whether you should lime the soil after planting. Acid-soil plants will need some liming to raise the pH near 4.5, but alkaline plants will require repeat limings through the fall to raise the pH even higher.

Tall shrubs and trees should be staked to protect them against winter storms; use heavy wire wrapped around short pieces of rubber hose to anchor the trunk. Most garden shops also carry stakes. Staking trees for 18 to 24 months is standard practice.

Other reminders:

If you forgot to move your holiday cactus indoors two weeks ago, the cactus will flower in mid-November instead of Christmas this year. The reason? The cool nighttime temperatures in the days before the Labor Day weekend. The flowers are triggered by two or three days of cool nighttime temperatures. Leave the cactus outdoors until nighttime readings drop into the mid-40s, at which time the plant will be moved indoors. Meanwhile, water every 12 to 14 days and fertilize every other watering with a 15-30-15 mixture.

Rains this week were a blessing, especially for those feeding lawns last weekend. The downpours also washed soil insecticides into the soil for those who just applied the grubproofing chemical.

Thanks to fertilizer and rain, you'll soon be cutting the old grass, then the new turf a week later. To show everyone your best lawn, buy a new rotary blade for your mower, then install it before you cut the old grass. Meanwhile, have the old blade sharpened so you have two perfect blades for mowing.

Remember the two-year-old strawberry plants spaded from the soil in August? Well, spade the runner plants and move them to vacant spots where some old strawberry plants grew. Always space new plants 36 inches apart, keeping the rows four feet apart. Water these plants well from here on so roots get their fill of water. Jack Eden hosts "Over the Garden Fence" Sundays from 10 a.m. to 1 p.m. on WTOP Radio (1500 AM).