What to do in your garden in September
SHOPPING AND PLANTING
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, andsea lavender (Limonium latifolium).
Order fritillary bulbs. This little-known genus in the lilyfamily bears nodding, bell-shaped flowers on stems from 6 inches to3 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 withpurple and reddish brown. F. persica has silvery foliage and dusky purple blooms. F. pudica bears tiny, fragrant yellow bells. Plant bulbs inwell-drained soil amended with compost in a spot that gets partialshade. Water regularly when they leaf out and bloom, lessfrequently during dormancy. A good source is McClure &Zimmerman (www.mzbulb.com or 800/883-6998).
Start autumn veggies. Sow seeds of cool-season crops now forlate-fall harvest. Prepare the bed by digging 2 inches of compostor well-aged manure into the soil to a depth of 6 to 8 inches. Keepthe bed evenly moist until the seeds germinate; use a floating rowcover to protect plants. Colorado State University CooperativeExtension recommends these crops and varieties: beets (‘DetroitDark Red’, ‘Ruby Queen’); carrots (‘Chantenay’, ‘Nantes Coreless’);lettuce (‘Black-seeded Simpson’, ‘Romulus’, ‘Sierra’, ‘SimpsonElite’); radishes (‘Black Spanish’, ‘Cherry Belle’, ‘Early ScarletGlobe’, ‘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 withblankets or sheets (not plastic). Remove covers promptly whentemperatures rise above freezing. If severe frost is predicted,pick apples, pears, and vegetables; finish ripening themindoors.
Care for houseplants. Before you bring them back indoors forthe winter, inspect carefully for insects. If you find them, spraythe foliage with insecticidal soap or a pyrethrum-based insecticidelabeled safe for houseplants. Thoroughly spray both the tops andundersides of leaves. This is also a good time to repot rootboundhouseplants in fresh soil mix.
Get advice online. Planttalk Colorado (www.planttalk.org) providesinformation on more than 400 topics, including flowers, fruits,houseplants, vegetables, weeds, lawn care, insect and diseaseproblems, and Xeriscape design.
Harvest vegetables. Pick all beans, corn, eggplants, melons,peppers, summer squash, and tomatoes before first frost. Pickwinter squash and pumpkins after a light frost. Dig potatoes afterall 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 harvestif mulched with 6 to 12 inches of hay or straw.