What to do in your garden in September


Instant fall color. For flowers now and for years to come, plant these perennials: asters, Boltonia asteroides, dwarf plumbago, false dragonhead (Physostegia virginiana), Gaura lindheimeri, giant daisy (Leucanthemella serotina 'Herbstern'), goldenrod (Solidago), Japanese anemone, Joe Pye weed (Eupatorium purpureum), pearly everlasting (Anaphalis margaritacea), pitcher sage (Salvia azurea grandiflora), rudbeckia, Russian sage, and sea lavender (Limonium latifolium).

Order fritillary bulbs. This little-known genus in the lily family bears nodding, bell-shaped flowers on stems from 6 inches to 3 feet tall. Fritillaria imperialis, considered the largest species, comes in many shades of yellow, orange, and red. F. meleagris bears flowers in solid white or checkered with purple and reddish brown. F. persica has silvery foliage and dusky purple blooms. F. pudica bears tiny, fragrant yellow bells. Plant bulbs in well-drained soil amended with compost in a spot that gets partial shade. Water regularly when they leaf out and bloom, less frequently during dormancy. A good source is McClure & Zimmerman ( or 800/ 883-6998).

Start autumn veggies. Sow seeds of cool-season crops now for late-fall harvest. Prepare the bed by digging 2 inches of compost or well-aged manure into the soil to a depth of 6 to 8 inches. Keep the bed evenly moist until the seeds germinate; use a floating row cover to protect plants. Colorado State University Cooperative Extension recommends these crops and varieties: beets ('Detroit Dark Red', 'Ruby Queen'); carrots ('Chantenay', 'Nantes Coreless'); lettuce ('Black-seeded Simpson', 'Romulus', 'Sierra', 'Simpson Elite'); radishes ('Black Spanish', 'Cherry Belle', 'Early Scarlet Globe', 'White Icicle'); and spinach ('Bloomsdale Long Standing', 'Indian Summer', 'Marathon', 'Medania'). More: Guide to salad gardens


Be ready for frost. If light to moderate frost is forecast, cover tender annuals such as marigolds, peppers, and tomatoes with blankets or sheets (not plastic). Remove covers promptly when temperatures rise above freezing. If severe frost is predicted, pick apples, pears, and vegetables; finish ripening them indoors.

Care for houseplants. Before you bring them back indoors for the winter, inspect carefully for insects. If you find them, spray the foliage with insecticidal soap or a pyrethrum-based insecticide labeled safe for houseplants. Thoroughly spray both the tops and undersides of leaves. This is also a good time to repot rootbound houseplants in fresh soil mix.

Get advice online. Planttalk Colorado ( provides information on more than 400 topics, including flowers, fruits, houseplants, vegetables, weeds, lawn care, insect and disease problems, and Xeriscape design.

Harvest vegetables. Pick all beans, corn, eggplants, melons, peppers, summer squash, and tomatoes before first frost. Pick winter squash and pumpkins after a light frost. Dig potatoes after all of the foliage turns brown. Cut broccoli before flowers open. Cabbage and lettuce can be picked at any stage. Beets, carrots, parsnips, and turnips can be left in the ground for winter harvest if mulched with 6 to 12 inches of hay or straw.

Find more great tips and seasonal ideas on our Garden page

DownComment IconEmail IconFacebook IconGoogle Plus IconGrid IconInstagram IconLinkedin IconList IconMenu IconMinus IconPinterest IconPlus IconRss IconSave IconSearch IconShare IconShopping Cart IconSpeech BubbleSnapchat IconTumblr IconTwitter IconWhatsapp IconYoutube Icon