In the garden/September. Be careful of Jack Frost; prepare poinsettias. The Monitor's monthly garden calendar is based on length of growing seasons.

If you want your potted poinsettia to bloom on time, start shortening its daylight hours beginning about Sept. 21 and continue the procedure to the first part of November. It has to be absolutely dark for a period of 14 to 15 hours each day. The plant can be covered with a black cloth or dark paper shopping bag, or set in a closet from about 5 p.m. until 7 or 8 o'clock the next morning. During the day put it in a bright window. Jack Frost is sneaky in September. Outsmart him by having some old bed sheets, black plastic ``tarp,'' or old newspapers on hand for covering tender items such as eggplants, tomatoes, peppers, zinnias, impatiens, and marigolds. Dig tuberous begonias, glads, and dahlias as soon as frost blackens foliage. If mums are still in tight bud when first frost hits, look for earlier varieties for next year. Budded ones can be dug and potted, then brought indoors to a sunny window. You can almost predict

a frost by taking the ``breath test'' about 7 p.m. If you see breath when you blow forcefully into the air, keep protectors ready. Pick pears while still green but when stem separates from branch as fruit is lifted up. Apples should be ripe (seeds should be dark brown) when picked. If tomatoes are slow to ripen, pull up entire vine and hang in garage. Catalogs and newspapers are loaded with bargains for fall planting. Study them. Also, visit local nursery or garden stores for spri ng-flowering bulbs. These can be planted anytime now and up until ground freezes. Evergreens can be moved now, or planted from the nursery. The secret is to get a good ball of roots and soil. Have hole already dug and be sure it is big enough. Water after ball is set into hole and again after soil is filled in. Leave a shallow, saucerlike depression around base of tree to catch water after soil has been tamped down. Add a 3-inch mulch of wood chips, sawdust, bark, and the like, but pull it away

from contact with trunk. Fermenting wood mulch produces wood alcohol that can injure trunk if mulch is in direct contact. In areas of high winds, newly planted specimens should be wrapped with burlap. Never use plastic; on sunny days it can trap heat inside and burn foliage.

Unlike Region A, Jack Frost doesn't threaten until end of the month or early October. Some gardeners plant fast-maturing and mildly frost-tolerant vegetables the first week in September. More gardeners are growing sweet potatoes, even in areas where there are only 31/2 frost-free months. If you planted Centennial (90 to 100 days from set plants), be sure to dig before heavy frost. Let tubers lie in sun 2 or 3 hours, put in baskets lined with papers, and cure in warm place (80 to 8 5 degrees F.) for about 12 days, then move to a spot that remains 55 to 60 degrees F. for storage. Pick Brussels sprouts only after a frost, which makes flavor sweeter. Soil is just right for planting spring bulbs. In addition to all the regular ones, try some Dutch iris (apply some mulch where temperature is apt to fall below -10 degrees F.). Also plant a few Camas or Quamash (Camassia esculenta) to enjoy a spring show of purple, star-shaped flowers. The b ulbs were a main food source of Northwest Indians. To have amaryllis rebloom, withhold water and store pot in cool basement or garage at 50 to 55 degrees F. without water for 2 to 3 months. When new shoot appears, it's a signal to move plant to a bright window and water regularly. Look over your fruit trees for leaf spot and any mummified fruit (especially on stone fruits). Rake up leaves and pick the dried fruits for garbage disposal. It will do much to prevent fruit rot next year

and will also help eliminate spores of leaf spot.

Plant a tree now. You can watch it grow and later enjoy its fruit and its shade. In addition, it attracts birds to your property. Fall planting is preferred over spring planting by many gardeners. You can plant strawberry plants in fall. If they are kept watered, they'll thrive and bear next summer, but some folks prefer to pick off blooms and let them bear a year later. Sow some seeds of Sweetheart strawberry in one of the soilless mixes (available at garden stores). Transplant into hanging baskets

when 1 inch high and grow in a bright window. In five months you'll have delectable berries for your cereal. Buy some mum plants at the garden store and set them around to add color to flagging flower beds. Pots can be sunk in ground temporarily and then planted in a permanent bed after flowering. Be on the lookout for free leaves. Some people foolishly bag them after raking and place them on the curb for a trip to the dump. Stockpile your leaves -- any kind. They make valuable humus to tighten a sandy so il or loosen a clay type. Try raising mushrooms indoors. Buy spores (``seed'') from any seed house and sprinkle them on rotted compost. Keep in a cool basement. Mushrooms need a temperature between 52 and 65 degrees F., plus darkness, since they are a fleshy fungus with no chlorophyll. Keep moist and avoid high temperatures. Instructions come with the package of spores. Some seed houses offer spores alone; others offer a whole kit, complete with rotted compost.

Nights will be cooling down shortly. Fast-producer Sugar Ann (edible podded) peas should be planted along with kale, collards, turnips, lettuce, spinach, and Swiss chard. If you planted late broccoli, pick when buds are tight. Small side shoots will develop for second crop. Parsnips, carrots, and beets can be planted for wintering over. Order spring flowering bulbs, but hold to end of month and cooler weather for planting. In addition to the regulars, plant some Fritillaria imperialis ( Crown Imperial). Both red and yellow varieties are striking and are considered a good rodent repellent. Cut mum plants back to six inches after flowering so they will be forced to form stolons (underground roots with shoots) for emergence next spring before you begin to divide plants. Pick apples and let them remain on the ground for a day or so, then bring indoors and store at 40 to 45 degrees F. if possible. Prune off water sprouts in apple and pear trees after fruit is off. Prepare late-harvested onion bulbs for storage after outer skin is dry. Remove tops about one inch from the bulb and store as cool as possible. Fat-necked ones don't store well, so eat them right away. If your neighbor has a nice patch of lily-of-the-valley plants and they are slightly overcrowded, offer to help separate and replant them for a few plants in return. Water well after replanting. Pot up a few roots (called pips) in 4-inch clay pots and refrigerate for 8 to 10 weeks. Then move them to a bright window so you can soon enjoy out-of-season fragrant blooms. If you time it right, you can have some in bloom for each of the November and December holidays.

Gardeners in this region can direct-seed almost any vegetable -- except tomatoes, eggplants, and peppers -- and get fall crops before frost. But be sure to look on the packets and buy ones that will mature early enough to avoid heavy frost 3 to 4 months hence. Folks who don't have tomato, eggplant, or pepper transplants may start some the first of the month for growing in containers that can be moved inside if frost comes before they produce a crop. Catalogs now list vegetables especially suit ed to containers. Three tomatoes we like are Burpee's Pixie Hybrid, Basket King hybrid, and Patio. If you raised goobers (peanuts), harvest them now, when the hulls are hard and soil is fairly dry. Cure them in sun for a day or so. Vines left on blacktop for 24 hours get enough heat to dry them. Solid organic practices will help your garden resist insects, disease, and cold spells. Build your own soil bank with all kinds of garden debris, kitchen scraps, grass clippings, and wood c hips. Cut off seed heads of perennials so they can't self-sow and crowd out original plants. To put some zip in fall and winter meals, sow some herbs in window boxes or pots so they can be moved inside during periods of heavy frost. Basil, oregano, sweet marjoram, summer savory, and sage all grow fast. Dill is great for salads and can be kept short if tops and leaves are regularly snipped and used.

In frost-free areas, late fall and winter are the growing season. Crops can be seeded directly or started in plant packs. Remember to first prepare soil by adding plenty of organic matter. Potatoes can be started now from cut-up tubers (be sure each piece has an eye). Sweet potatoes are nearing harvest and will be ready to dig when leaves turn yellow. In areas with some frost, be sure vegetable plants will mature beforehand when you choose varieties to plant. Or choos e vegetables (cole crops, spinach, peas, etc.) that are frost tolerant. Daffodils, tulips, and hyacinths do not do too well in Region F. You can still enjoy blooms, however, by refrigerating the bulbs for 8 weeks before planting. They will bloom satisfactorily the first season because the cold treatment breaks dormancy and a good root system develops. Plant 12 inches deep for best performance. Sow seeds of perennials that are grown as annuals to start flowering in March. These incl ude Liriope, gaillardia, Mirabilis, salvia, Shasta daisy, Vinca rosea. There are several annuals that are frost resistant and also tolerate high temperature and resist garden pests and heavy rain. Some are bells of Ireland, browallia, calendula, carnation, annual chrysanthemum, Clarkia, and Cuphea. Keep fruit trees watered, even though they are through bearing. The next crop will depend on how well they are cared for now. Dry soil is a strain on fruiting trees as well as ornamental ones.