The American Organic Gardener's September To-Do List

Everything that needs to be done in the dirt this month, wherever you live.

September 5, 2017
planting bulbs

Here's your September gardening guide for North America's USDA Plant Hardiness Zones: 3-10. (Did you know that the USDA Hardiness Zones have changed?)

If you don’t know what USDA Plant Hardiness Zone you live in, check the map here to find out.

We've left off zones 1–2 (far-north Alaska) and zones 11–13 (small section of the Florida Keys, the Pacific coast between L.A. and Mexico, and Hawaii) since zones 3–10 cover 99 percent or more of the gardeners in the U.S.

(Whether you're starting your first garden or switching to organic, Rodale’s Basic Organic Gardening has all the answers and advice you need—get your copy today!)

harvesting corn
Zone 3
  • Plant new fall bulbs so they develop roots before the ground freezes.
  • Harvest corn, potatoes, apples, cucumbers, tomatoes, squash, and strawberries before a killing frost.
  • If tomato vines are covered with green fruit, pull up whole plants and hang them in a basement or garage until fruits ripen.
  • After onion tops have fallen over, dig the bulbs and let them cure on the soil surface for about a week before you store them.
  • After harvesting, spread compost over the soil surface.
  • Rake leaves and clean up plant debris, then add them to the compost pile.

Related: Beginner’s Guide To Seed Saving

sunflower seeds
Zone 4
  • On the first of the month, plant spinach for overwintering.
  • Use up any remaining compost in your bins to make room for the leaves you’ll soon add.
  • Dig up and store tender bulbs and tubers, such as cannas and dahlias.
  • Pick the seedpods and heads of any open-pollinated flowers you want to grow again next year; store the seeds in a cool, dry spot.
  • Set out pansies, mums, and kale for later fall color.
  • Plant garlic and other bulbs in mid-month.
  • Get ready to protect tender plants from early frost with row covers and blankets.
  • Look for dry pods on bean plants; save the seed for planting next season.

Related: How To Harvest Sunflower Seeds

planting bulbs
Zone 5
  • Sow seed of next year's biennial flowers, such as forget-me-nots (Myosotis sylvatica), sweet William (Dianthus barbatus), and foxglove.
  • Plant spring-flowering bulbs.
  • Dig up tender dahlias, cannas, caladium, and gladiolus before frost hits; store tubers and bulbs in a cool, dry spot.
  • Start spinach and kale under row covers or in a coldframe for tasty winter salads.
  • Still time to patch bare spots in the lawn—cover grass seed lightly with compost.
  • Plant perennials to take advantage of cool weather and rainfall.
planting spinach seeds
Zone 6
  • Get fall compost cooking with the last of your grass clippings, spent plants, and leaves.
  • As garden beds empty, sow quick-growing cover crops like winter rye.
  • Sow spinach mid-month for spring harvest.
  • Work spring-flowering bulbs into perennial beds.
  • Plant garlic by month's end for harvest next June.
  • Dig up, divide, and replant clumps of overgrown perennials.
trimming hedges
Zone 7
  • Early this month, sow seeds of mixed greens for fall and winter salads.
  • Harvest young lettuce planted in August.
  • Snip off long stems of parsley and freeze them in a bag or jar for winter use.
  • Trim evergreen hedges (such as holly and privet) on the first cool day.
  • Set out pansies in a spot that will receive full sun all winter.
  • Harvest peanuts as soon as shells become hard.

Related: 4 Genius Alternatives To Drying Herbs

transplanting broccoli
Zone 8
  • Plant transplants of broccoli, cauliflower, cabbage, and kale; surround them with a thick mulch to cool the soil.
  • Direct-seed spinach, lettuce, beets, carrots, parsley, turnips, and kohlrabi.
  • Plant pansies, stock (Matthiola incana), snapdragons, sweet alyssum (Lobularia maritima), Johnny-jump-ups (Viola tricolor), and pinks (Dianthus spp.).
  • Apply a 1⁄2-inch layer of compost to areas of the lawn that are susceptible to brown patch; apply organic fertilizer to the entire lawn at the end of the month.

Related: How To Grow The Most Gorgeous Chrysanthemums This Fall

small pumpkin harvest
Zone 9
  • Plant winter lettuce, peas, carrots, cole crops, and Asian greens.
  • Harvest winter squash and pumpkins before frost, when their skin is hard enough to resist pressure from your thumbnail.
  • Set out transplants of calendula, primroses, larkspur (Consolida ambigua), snapdragons, bachelor's buttons (Centaurea cyanus), stock (Matthiola incana), and pansies.
  • Refrigerate spring bulbs for 6 weeks to plant later this fall.
  • Pick ‘Bartlett' pears for ripening indoors, but allow Asian pears and ‘Seckel' pears to ripen on the tree.
  • Protect grapes from birds and wasps by covering the ripening clusters with brown paper lunch bags.

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Zone 10
  • Prune poinsettias for holiday bloom.
  • As grasshopper numbers die down, plant tuberoses (Polianthes tuberosa), gloriosa lilies, amaryllis, and other subtropical bulbs and rhizomes.
  • Plant okra. It’s your last chance of the season.
  • Seed cucurbits and herbs, and set out transplants of tomatoes, peppers, and onions.
  • Repair or replace drip irrigation lines.
  • Work in soil amendments, including compost, bonemeal, and greensand.