THE COMING OF THE FIRST FROST: The timing of the first frost is not necessarily tied to higher elevation. Both Willcox, at 4167 feet, and Benson, at 3585 feet, may experience late October or early November frosts while Bisbee, at 5350 feet, may experience first frost two weeks later, even though it is at a much higher elevation. This is because colder air sinks, and if there is little air movement, the cold air becomes trapped in valleys and low areas of yards. Communities like Palominas are especially prone to October frosts. Of course, as with all attempts to predict weather, there are variations from year to year, and sometimes from yard to yard. In mid-October, start paying closer attention to nighttime temperature, and be ready to protect frost sensitive plants.

THE HARDEST JOB OF ALL: Most gardeners would rather eat shrink-wrapped lettuce than thin their tiny vegetable seedlings. Unfortunately, that's what we may end up doing. Without thinning, seedlings are often forced to battle each other for nutrients, water, and growing space. The result is weak, under-developed vegetables, and disappointed gardeners. If you planted a winter vegetable garden, grit your teeth, steel-up your spine, and start thinning. Remove enough seedlings so that the remaining vegetables are the proper distance from one another. If you'd rather not thin, plant only one seed in each hole at planting. Your germination rate will be lower, but you will also not be faced with the Gardener's Dilemma. Thinnings, by the way, make good salads!

OVERSEEDING LAWNS: Warm season grasses, such as Bermuda grass, are entering a winter rest period. If you want to keep your lawn area green through winter, overseed this month with a cool season grass such as annual or perennial ryegrass. The cool season grass will flourish in the cooler temperatures and go dormant during the hot days of summer when the warm season grasses are at their peak.

PLANTING BULBS: Aim to have all of your spring and early summer blooming bulbs planted 4 to 6 weeks before the first hard frost. For most of us, the end of October marks the end of spring bulb planting. See our feature article this month for more on planting spring bulbs.

DON'T LET YOUR WEEDS GO TO SEED: If you have let your weed vigilance relax a bit during the last month, go at them with a vengeance now. Bag, rather than compost, any weeds that already have seed heads.

DIVIDING PERENNIALS: Spring or early summer blooming perennials need to be divided every 2 to 4 years in the fall in order to keep them strong and blooming. (Late summer and early fall perennials should be divided in early spring.) A clumping perennial that is never divided often produces weak growth, and is vulnerable to pests and diseases. Plus, dividing is a great way to get more plants without spending more money - every gardener's dream. Before dividing, prepare the hole where the divided portion will be planted, and don't let the roots dry out. To divide a clumping perennial (it's okay if it still has leaves as long as it is a spring or summer bloomer), cut around the plant's rootball with a shovel, then push the shovel underneath the rootball and lift the plant to pry the rootball loose from the soil. Insert two pitchforks, or a small garden fork or knife, in the center of the perennial and work them back and forth until the rootball begins to separate into two halves. You can often use your hands to divide smaller plants. Plant one half in its new location, and return the other half to the original planting hole.