• If you don’t have a compost pile, this is a great time to start and use one.
  • September 22nd is the average first frost date. Killing frost to tender plants occurs when temperatures reach 26-30 degrees.
  • If frost catches your garden, don’t rush to harvest frozen produce. It will only cause unnecessary bruising damage. Let produce and soil warm before harvesting. If produce turns black it was already beyond salvage.
  • Apples, chokecherries, plums, gooseberries and currants all continue to ripen after a frost, and actually contain more sugar.
  • For root crops, let the ground warm a few days to allow slow thawing. Potatoes & onions store better after frosts kill back the tops.
  • If possible, cover tender plants to protect them from frost, in the hopes that an Indian summer will extend the growing season. Try to keep covers off foliage, as frost will pass through them and into any foliage that they touch. Always remove covers by mid morning. Otherwise, plants may become burned as heat builds up.
  • If a light frost sneaks up on you, sprinkle down the garden to prevent a fast thaw. This is best done before the sun hits the foliage.


  • Harvest potatoes after the vines have died to the ground, often following the first killing frost. After digging, allow tubers to cure out of direct sun for a day or so. This allows the skins to toughen and reduce bruising. Wash in running water. Avoid using a brush, as this will break the skin and invite decay. It helps to store potato tubers at 60-70 degrees for 2-3 weeks, prior to winter storage. Then store at temperatures between 35-38 degrees, with moderate humidity.
  • When onion tops naturally fall over, they are through growing. After digging, allow bulbs to lie in the sun for several days to mature the outer scales to a papery state. Onions with thicker necks should be used first, as they will not store as well as thinner necked onions. Twist tops off of bulbs rather than cutting. This helps seal the bulb from fungus. Store at 50-55 degrees in a dry location.
  • Other root crops like carrots and rutabagas should be handled carefully to avoid bruising. Cut the tops about an inch from the roots and do not scrub to remove soil. Store at 32-34 degrees, with moderate humidity, in the dark. Parsnips and carrots are often harvested later (October) or mulched in the garden, as they develop higher sugar levels with the cold temperatures of fall.
  • Cabbage, broccoli, cauliflower, etc. can take temperatures down to 25 degrees.
  • After harvest is finished, add organic materials (gypsum, etc.) and till soil to expose overwintering insects and get a jump on gardening next spring.
  • Harvest pumpkins and winter squash after light frost, but before a heavy freeze. Cut fruit from the vine with about a 3-inch portion of the stem attached. Cure by placing in a heated, ventilated area at 75-80 degrees for two weeks. This hardens the shell for storage. (Do not cure acorn squash). Store pumpkin and squash at 40-50 degrees after curing.


  • Don’t remove fire blighted apple wood until dormancy.
  • Remove bearing canes of raspberries after last picking. Also, remove weak shoots.
  • Try to harvest apples if temperatures are expected to get below 25 degrees.


  • Refrain from watering established trees and shrubs from mid September to mid November (or when trees start turning their fall color). This helps encourage dormancy. Heavy irrigation, nitrogen fertilizers and pruning (except for dead wood) can cause trees to break dormancy and begin new growth, making them susceptible to winter injury. If however the fall turns out to be long, hot, and dry, irrigation may be needed again. Continue irrigating newly transplanted trees and shrubs (up to three years after being planted) as usual.
  • Put tree wraps on tender, dark barked trees, to prevent sun scorch.


  • 15 - Sept. 15 is one of the best times for lawn grass seeding. If you need to do some re seeding, try to get to it before mid September.
  • Continue watering lawns throughout the autumn season. Fall, with its long cool evenings, favors the dense, vigorous growth of Kentucky Bluegrass.
  • Continue mowing right up till winter sets in. Long, matted grass invites winter disease problems.
  • Rake leaves off of grass. If left on the lawn over winter, these may suffocate the grass.
  • Extension Horticulture Specialist, Bob Gough, recommends fertilizing around these holidays: Memorial Day, Labor Day and Columbus Day. General lawn fertilizer recommendations: 6-7 lbs. of 24-4-4 per 1,000 square feet of lawn.


  • Divide crowded peonies, replant top buds 2 in. deep.
  • September through early October is the time to plant spring flowering bulbs. In our higher elevation, it is recommended that bulbs be planted approximately 2 in. deeper than suggested on most bulb planting guides.
  • Dig gladiolus bulbs after the first frost, cutting off tops just above the corm. Cure by spreading out in a dry, frost-free location for 2-3 weeks. Remove old shriveled corms by snapping off cleanly. These will be attached to the bottom of the new corms which have developed on top of the older ones. Dust with an all-purpose, rose dust, store loosely in open trays, in a dark place at temperatures of 40-50 degrees.
  • Dig dahlias after frost, by lifting the clump of tubers with a spading fork. Avoid damaging the necks of the bulbs, since this is where vital growth buds are located. Shake off loose soil, cut tops a couple inches above ground level. Don’t divide till spring. Dry the clump well, but don’t allow roots to shrivel. Place in plastic bags with lightly dampened peatmoss or vermiculite to prevent shriveling. Store in cool, frost-free area at about 40 degrees. Inspect often for mold, opening bags to allow drying if needed.