Michigan State University Extension-Oakland County Monthly Garden & Landscape Guide September Use these tips to keep your landscape and garden in great shape throughout the year. Flowers Bulbs Prepare beds for planting of spring flowering bulbs. Choose a well-drained site, clear all weeds, and incorporate a thick layer of organic matter. Apply a fertilizer such as 10-10-10 at 1 to 2 lbs./100 sq./ft or Bulb Booster (9-9-6) at 3 to 5 lbs./sq. ft., superphospate, or other commercial bulb fertilizer. Plant spring flowering bulbs beginning in late September. Planting too early can cause bulbs to sprout top growth before winter. However, allow at least four to six weeks before the ground freezes for good root formation. If you are putting in bulbs as part of a perennial bed, plant them after all other plants have been installed. For a different look, mix several types of spring bulbs (of similar height), and scatter them at random over the bed, adjusting only for proper spacing. As a general rule, bulbs should be planted three times as deep as their greatest dimension. The deep planting of tulips is the exception. Plant spring-flowering bulbs according to the chart on page 2. Before the ground freezes, and after frost has killed the tops, dig and lift roots of tuberous begonia, gladiolus, cannas, and dahlia. Knock excess dirt off the roots and remove foliage, leaving a short stub. Let roots air dry for several days. Store on newspaper or in mesh bags or old nylons or in dry sand, sawdust or peat moss in a cool, dry, frost free garage or basement. Check them occasionally and discard any showing signs of mold or decay. Annuals Take cuttings of easily rooted plants for indoor winter color. Spray or dip the cutting to remove insects before bringing indoors. Wax begonias and impatiens can be dipped in rooting hormone powder and stuck in damp sand. Coleus shoots will root in a glass of water on the window sill. Clean up plants, which have finished blooming and add them to the compost pile. Keep summer annuals blooming until frost by picking off faded flowers and
seedheads and watering the plants during dry weather. Harvest strawflowers, statice, baby s breath and celosia for drying when the blossoms are about half open. To dry them, hang upside-down in a dry, wellventilated area out of direct sun. After the first freeze, mulch the bed to avoid heaving. Perennials Phlox, daylilies, iris and peonies can be divided and replanted at this time. Daylily clumps can be split with a spade or a pair of spading forks; new clumps should be about the size of a softball. This is a great time to lift and divide peony crowns. They should be split with a sharp knife. Divisions should have at least 3 to 4 eyes and should be reset with the eyes close to the surface. Shallow eyes are better bloomers. Watch for garden chrysanthemums to bloom as days grow shorter. Some may have bloomed earlier this summer, which will decrease the number of fall blooms. Continue applying preventive sprays for powdery mildew on asters. You can still add new plants to the bed. Even if plant crowns are dormant, plants will continue root growth if the ground is workable. Begin cutting back plants that are not vigorous or which have finished blooming. Add waste to the compost pile. Do not compost plants suffering from disease. Planting Spring-Flowering Bulbs Variety Depth Spacing Allium small 4" 4-6" large 6" 6-8" giant 6" 10-12" Anemone 3-5" 4-6" Camassia 4" 4-6" Chionodaza (Glory of the Snow) 3-4" 2" Crocus 4-5" 3-4" Daffodil/Narcissi <10" 4-6" 2-4" >10" 6-8" 3-8" Eranthis (Winter Aconite) 2" 2-4" Erythronium 2-3" 2-4" Fritillaria tall 5-6" 12-15" short 3-4" 5" Galanthus (Snowdrops) 3-5" 2-4" Hyacinth 6" 6" Dutch Iris/Dwarf Iris 5" 2-4" Leucojum (Hardy Snowflake) 3" 3-4" Muscari (Grape Hyacinth) 3-5" 3-4" Puschkinia (Striped Squill) 2-4" 4-5" Scilla 5" 3-4" Tulip 8-12" 4-8"
Roses Continue to spray roses to protect them against diseases and insects. Prepare soil for spring beds. Roses enjoy somewhat heavy soil, so supplement soils with a generous amount of organic matter (manure or compost). Leave the rose hips on roses to encourage dormancy. NO PRUNING! Roses need to begin to harden off to prepare for overwintering. Fruits A final cover spray should be made on early this month for the control of apple leafhopper, apple maggot, oriental fruit moth and peach tree borer. Continue to remove and destroy any fallen fruit. Continue the harvest of grapes, apples and fall-bearing raspberries. Harvest apples, pears, grapes and everbearing strawberries and raspberries. For most fruits, flavor is the best indicator of ripeness, although color change also can be a good indicator. However, pears are best ripened off the tree, and grapes change color long before they are fully flavored, so sample the fruit to be sure. Remove the raspberry canes that fruited this year, and thin weak or broken canes and prune out diseased ones. Herbs Dig chives, parsley, rosemary, Greek oregano, Cuban oregano and other tender perennials and plant them in containers for a winter windowsill herb garden. Harvest remaining herbs and dry them where they won t be exposed to heat or direct sunlight. A small clump of chives, while winter hardy, can be brought in for some fresh flavor. Lawn Grubs can be controlled in September. Products containing dylox or sevin are effective in granular form. Products containing Merit or Mach 2 should not be used at this time. Insecticides need to be watered in thoroughly. Spot seed bare areas in lawns with seed of similar grass species. In sunny lawns, this usually means a blend of improved bluegrass cultivars. In shaded lawns, use a mixture of ryegrasses and fescues. Loosen the soil before seeding. Water daily, more than once if necessary, to keep the soil moist until seedlings are well established Around Labor Day fertilize established lawns with a completer fertilizer. If your lawn has heavy traffic or a thick layer of thatch build up, core aerate the lawn before you fertilize. Continue to monitor for diseases such as Dollar Spot and Necrotic Ring Spot. Establish a new lawn from seed before September 15. Rake leaves as they fall so they don t mat on the lawn and smother the grass plants. Add leaves to the compost pile after grinding or chopping them and mixing them with a little soil and fertilizer to
speed decomposition. If you don t like the thought of raking autumn leaves, they can be incorporated into your lawn. 1996 research found that a large amount of leaves can be added by regularly going over the lawn with a mulching lawnmower. The lawn continues to look good and benefits from the extra organic matter. Trees, Shrubs & Vines Fall is a good time to plant many container grown or balled and burlapped nursery stock. Before planting, be sure to remove wire and plastic cords from trunks and stems, and to remove burlap and other non-biodegredable materials from the soil balls. Prepare a good sized hole, plant at the same depth it grew in the nursery and water thoroughly. Mulching will help protect against large fluctuations in soil temperature and moisture. Do not be alarmed if your evergreens, particularly white pine and arborvitae, drop some older needles. All evergreens shed needles at some time, just not all at once as deciduous plants do. You may dig and move established shrubbery. You can still plant evergreens right now, but do it as early as possible. Treat overwintering adults of spruce gall adelgid. An ideal time is during the peak coloration of sugar maples. If the weather is dry, water trees and shrubs weekly, especially newly planted ones. Do not fertilize woody ornamentals now, however. They would respond with a flush of growth that would probably be killed or injured by cold weather. You can fertilize after the first hard frost or when the plants are fully dormant but before the soil freezes. Nutrients applied then will be available to the plants as soon as they begin to grow again in the spring. Vegetables Dig onions and garlic after tops fall over naturally and necks begin to dry. Thin fall crops, such as lettuce and carrots, that were planted earlier. Extend the summer harvest by saving tomatoes, summer squash, peppers, eggplant and other tender crops from the first killing frost. Cover plants with blankets, newspapers, plastic or some other material that will trap heat given off by the soil at night. The cole crops (broccoli, cauliflower, cabbage and Brussels sprouts), carrots, parsnips, lettuce and spinach will tolerate some frost. Mature green tomatoes can be ripened indoors. Individually wrap fruits in newspaper, or leave them on the vine, pulling the entire plant out of the garden. Store in a cool location; about 55 to 60 F. Harvest winter squash when mature (skin is tough) with deep, solid color, but before hard frost. Some cultivars will show an orange blush when mature. Exposure to low temperatures will damage their skins and shorten their life in storage. Store leftover garden seed in a cool, dry place. A sealable jar with a layer of silica gel or powdered milk in the bottom works well.
When harvesting pumpkin, gourds and winter squash, cut from the vine leaving a portion of stem attached to the fruit. This will improve the storage life of the fruit. As the harvest ends, clean up plants and add them to the compost pile, do not compost plants suffering from disease. Would you like additional information? Additional information is available on-line. Please see MSU Extension- Oakland County s publications as well as MSU Extension s Bulletin Office on campus. Contact our Plant & Pest Hotline (248/858-0902) for assistance with plant identification, pests and diseases, weeds, trees and shrubs, lawn, flowers, fruits, vegetables, grasses and groundcovers, native plants, plant propagation, and many other gardening topics. Distributed by MSU Extension-Oakland County, 1200 N. Telegraph Road, Pontiac, MI 48341, 248/858-0880, www.msue.msu.edu/oakland MSU is an affirmative-action equal opportunity employer. Michigan State University Extension programs and materials are open to all without regard to race, color, national origin, gender, gender identity, religion, age, height, weight, disability, political beliefs, sexual orientation, marital status, family status or veteran status.