Extension Fall Garden Packet--II
Published: Aug. 29, 2005
August 29, 2005
Source: Barbara Bates (630) 584-6166 Contact: Bob Sampson Extension Communications Specialist Phone (217) 244-0225; rsampson@uiuc.edu
Storing Tender Bulbs
Some of the most beloved garden plants grow from "tender bulbs," which means they need special care in the fall and winter, said a University of Illinois Extension horticulture educator.
"Dahlias and gladiolas are examples of plants with tender bulbs," said Barbara Bates. "Tender bulbs are plants that are not hardy in the Midwest. These storage organs may include corms, tuberous roots, rhizomes, and bulbs. These plants should be dug up in the fall and stored in a cool place for the winter."
Many summer flowering or tropical foliage plants are also classified as tender bulbs. These include Blackberry lilies (Crocosmia), elephant ears (Colocasia and Alocasia), cannas, callas, tuberous begonias and others.
"It is recommended that the underground parts of these plants be dug after the first frost," said Bates. "A digging fork is less likely than a shovel to damage the storage organs. Disease organisms that cause decay can enter through wounds and bruises.
"As you dig, keep bulbs separated by kind and color. Label these as you handle them so you'll know what you have when you get ready to design and plant next spring."
Excess soil should be shaken off bulbs and corms, and then the stems should be cut off. Soil should be washed from the roots and the rhizomes by placing them on a mesh or screen and gently rinsing away the soil. After inspecting the bulbs for damage, discard any damaged ones along with the runts.
"Corms such as gladiolas and callas should be cured before storing," she said. "Cure them by air-drying them at 60 degrees F out of direct sunlight for three weeks. After curing, remove the old shriveled corms at the base of the mother corm."
Tender bulbs should be stored by layering them in a ventilated container. They should be layered with peat moss, sand, shredded newspaper, or sawdust. The stored bulbs should not be touching one another as this can lead to the spread of decay should it occur.
"Check your bulbs several times during the winter to remove the rotting ones, and to check the moisture level," said Bates. "Bulbs that shrink and wrinkle are too dry. If this occurs, moisten the layering media a tad and re-pack them."
Bates said storage temperatures should be between 40 and 50 degrees F.
"Basements are often an ideal place, where rodents will be unlikely to get the stored bulbs," she said. "However, finished basements and utility rooms will likely be too warm. Put the bulbs near an outside wall, away from heat sources. An unheated garage or crawl space can work well. Be sure to store the bulbs in a 'mammal-proof' container."
The tender bulbs will be ready to plant next spring, after the soil has warned.
"For earlier display, start them indoors in pots to be transplanted later," Bates said. "Or use them as container plants."
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August 29, 2005
Source: Greg Stack (708) 720-7520 Contact: Bob Sampson Extension Communications Specialist Phone (217) 244-0225; rsampson@uiuc.edu
Minor Bulbs
Most gardeners will busy themselves in the fall preparing for spring color by thinking about spring flowering bulbs, but what about adding unusual flowers and different colors to the garden by using what are often referred to as minor or miscellaneous bulbs, asked a University of Illinois Extension horticulture educator.
"The minor bulbs comprise a whole group of bulbs that are often overlooked or at least not planted in great quantities, but can prove valuable from the standpoint of offering early color, unusual flowers, and the ability to be long-lived in the garden through naturalization or perennialization," said Greg Stack.
"Many of these bulbs naturalize or perennialize well, which means that if given a good location and left undisturbed, they just get better with each passing year."
Before deciding what minor bulbs to plant, it is important to look at bulb basics, he noted.
"Heavy soils, either wet or dry, are not conducive to successful bulb gardening," Stack said. "It is worth the effort and expense to prepare the soil BEFORE planting bulbs. Work in large amounts of compost and spade it into the soil a minimum of 12 inches. It does no good to add amendments to the soil if it is above the level of the bulb's base where all the root action is located."
Drainage is important for 99 percent of all bulbs, he added.
"If you expect to see bulbs last for more than one season, good drainage is very critical, especially during the dormant season," said Stack. "That translates to the summer for spring-flowering bulbs and the winter for summer-flowering bulbs.
"Tulips that are great perennializers include the Species, Greigi, and Foseriana types. But even their useful garden life is cut short if they are planted underneath annuals that get regular watering during the summer."
For some of the lesser-planted bulbs, gauging planting depth can be helpful. Plant all bulbs three times their height deep. That means look at the bulb's height in inches and multiply by three. That will give you the proper depth and planting distance apart.
Those that want to venture from the ordinary or add a bit of difference to the garden might want to consider spring-flowering minor bulbs.
"Well-supplied garden centers often carry a selection of minor bulbs," said Stack. "If you can't find them locally, there are several excellent mail order bulb suppliers that can get you started and satisfy your taste for the unusual."
Stack said that the alliums or "flowering onions" are unique, exotic, and loads of fun. They can extend the bloom period well into June with flowers up to six inches in diameter.
"Flowers often have the look of your favorite star-burst firework at the annual Fourth of July display," he said. "One of the better ones for naturalizing is Drumstick Allium--Allium sphaerocephalon. It has dark, crimson-purple, egg-shaped flowers that grow up to 24 inches tall. The low-growing foliage is often best hidden by other low growing perennials and allows the flowers to appear magically suspended above the garden.
"All alliums prefer well-prepared, well-drained soil in a sunny location. The flowers are excellent fresh-cut or can be dried."
A blast from the past is Fritillaria or Crown Imperial.
"Fritillaria were a garden favorite dating back to the 1500s," he noted. "This show-stopper produces a 30-inch flower stem that sports a leafy, tufted crown of foliage with 10 or more bell-shaped flowers handing from below. Colors range in the oranges and yellows. It demands very good drainage in a site that is semi-shaded."
The Checker Lily or Guinea Hen Flower is another Fritillaria that is sure to catch attention. It is a terrific naturalizer and is noted for its bell-shaped flowers that are shades of white or purple and spotted or checked much like a picnic table cover. At eight inches tall, it makes a great low-growing colorful display.
"To be successful with Fritillaria, you need to understand the bulb," said Stack. "When you buy them, you will think you have purchased a well-aged cinnamon roll that has been sitting around a bit too long because of the rather malodorous scent--somewhat like a skunk.
"When planting Fritillaria bulbs, fill the spaces between the rings with sand and plant them propped on their side. This will prevent water from pooling on the surface of the bulb and rotting it."
Rock Garden Iris (Iris reticulate) are great bulbs for naturalizing in rock gardens or borders, quickly producing offsets that multiply into generous drifts of color. These four to six-inch tall flowers start blooming in April and have upright inner petals and downward outer petals showing off a contrasting color on the petal spine.
Eremurus, also known as Desert Candles or Foxtail Lily, is a spectacular plant growing to three to four feet tall. The flower stems are covered for half their length in hundreds of small flowers from early May to June, opening from the bottom to the top and eventually giving the plant the look of a bottle brush or foxtail.
"They are extremely easy to grow, which should put them on the top of everyone's list," said Stack. "These bulbs prefer a sandy, well-drained soil that is in bright sun. Once planted, they like to remain undisturbed, making them good candidates for naturalization."
For those who demand tulips in the spring, Stacks noted that some offer the ability to perennialize and become almost permanent features in the garden.
"Kaufmanniana tulips, also known as water lily tulips, are colorful and are low-growing tulips perfect for border plantings," he said. "The large flowers are produced on short stems and, when fully open, resemble water lilies. Some varieties even have beautifully mottled foliage to go along with the flowers. These are great naturalizers when left undisturbed."
Greigii tulips are desired for their exquisite foliage to which is mottled and streaked with purple stripes. These short tulips--10-12 inches--are good for the front of the border and will produce a colorful display of flowers that open and close in response to sunlight.
"For late-flowering delight, consider the Multiflowering Tulips," said Stack. "These May bloomers produce a bunch--four to five--of full-sized flowers per stem. The blooms make a full garden display and make it pretty easy to pick a bunch of tulips for that special vase.
"All of these examples only scratch the surface of what can be found under the miscellaneous or minor bulb category."
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August 29, 2005
Source: Susan Grupp (630) 653-4114 Contact: Bob Sampson Extension Communications Specialist Phone (217) 244-0225; rsampson@uiuc.edu
Lawn Repair
Late summer and early fall is an ideal time to renovate your lawn, said a University of Illinois Extension horticulture educator. For a thicker, more attractive lawn, re-plant seeds into your existing lawn.
"Most Illinois lawns are planted with blends or mixes of Kentucky bluegrass, perennial ryegrass and fine fescue, and mid-August to mid-September is an ideal time to over-seed," said Susan Grupp. "There is less weed competition from pesky annual weeds in the fall. Also, planting seed in the fall gives young grass plants enough time to develop a good root system before next year's summer weather.
"Improve your lawn's appearance and quality by choosing seed that is disease and insect resistant, drought tolerant, and suitable for the sun/shade conditions in your yard. While you might be tempted to just toss the seed across your lawn, you may be disappointed with the results. The key to success is making sure there is good seed-to-soil contact. Without that good contact, you probably won't get good germination."
Grupp recommends using a slit seeder machine, which cuts into existing grass and places the seed directly in the soil, to overcome this problem. For bare areas, roughen up the soil a little before broadcasting the seed.
"Some lawns decline because of poor soil conditions," she said. "For low-moderate soil compaction, using a core-aerifier may be a good option. This self-propelled machine removes plugs or cores of soil and grass and deposits them on the lawn surface. Do not remove the plugs--simply let them dry out. A few days later, mow over them with a lawnmower.
"For best results, core-aerify in one direction--north to south--across your lawn and then take a second, perpendicular run--east to west. This will produce more plugs per square foot. Make sure you have 15-20 plugs per square foot."
Grupp noted that core-aerifying helps improve soil compaction, poor drainage, and also helps reduce the thatch layer.
"However, if you have extreme conditions of compacted clay soil, or thatch greater than three-fourths inch, then core-aerifying may not be enough," she said. "These severe conditions may require starting over with a new lawn on properly prepared soil."
Late summer and early fall is also a good time to control perennial lawn weeds. Once weeds die, the cooler fall temperatures encourage lawns to grow rapidly and fill in.
"Be sure to identify the weed properly before choosing a control method," said Grupp. "Also, do not broadcast an herbicide across your entire lawn if spot treating will do the trick."
For further recommendations, Grupp recommended Extension's Lawn Talk web site, located at: http://www.urbanext.uiuc.edu/lawntalk .
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August 29, 2005
Source: Maurice Ogutu (708) 352-0109 Contact: Bob Sampson Extension Communications Specialist Phone (217) 244-0225; rsampson@uiuc.edu
Planting Garlic
Planting garlic in the fall, six weeks before the ground freezes, is the best way to ensure that the plants will begin to emerge in March or early April, said a University of Illinois horticulture educator.
Maurice Ogutu listed a number of garlic varieties that perform well in Illinois. These include: Hardneck types--Georgian Crystal, Music, Carpathian, Spanish Roja, Metechi, and Persian Star, and Softneck types--Inchelium Red and Idaho Silverskin.
"There are several other varieties available and a home gardener can choose any of these as long as it is adapted to the local climate," Ogutu said.
Garlic bulbs for planting need to be stored at temperatures between 40 and 50 degrees F.
"Most of the garlic bulbs in supermarkets are the softneck type and are not recommended for planting," he said. "New garlic growers need to purchase bulbs from local garlic growers or through seed catalogues."
Each garlic bulb is made up of several cloves held together by a thin membrane. Each clove consists of two miniature leaves and a vegetative bud. The bulbs should be separated into cloves when you are ready to plant. Only the larger outer cloves should be planted in order to ensure large bulb production.
"Garlic requires full sun, and deep well-drained, fertile soil with a pH of six to seven," Ogutu said. "Garlic performs well in soil with plenty of organic matter so add plenty of compost, well-rotted manure, or till under green manure crops. Apply about three pounds of 10-10-10 fertilizer or the equivalent per 100 feet before planting."
The cloves should be set up into the soil in an upright position (basal plate down) about two inches deep, spaced three to six inches apart within the rows. The rows should be 12 to 36 inches apart, depending upon the variety.
"Planting time is very critical as shoot and bulb development require cold treatment," he said. "Most of the leaf growth will occur when it is cool and day lengths are short. Leaf growth stops and bulb formation begins when it becomes warmer and day lengths are long."
Ogutu recommends mulching the rows with four to six inches of weedseed-free straw mulch to moderate soil temperatures by minimizing fluctuations in winter and early spring, and to control the weeds.
"The mulch should be left in place throughout the entire growing season to control the weeds and conserve moisture," he said. "However, in abnormally wet spring conditions, mulch may be removed after the danger of a hard freeze is gone so that the soil can warm up."
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August 29, 2005
Source: James Schuster (708) 352-0109 Contact: Bob Sampson Extension Communications Specialist Phone (217) 244-0225; rsampson@uiuc.edu
Fall Garden Chores
Fall is the time to take care of any garden chores left undone, said a University of Illinois Extension horticulture educator.
"If your trees need to be fed, now is a good time to do so. Do it before the ground starts to freeze and the temperature is still above 40 degrees," said James Schuster. "Trees that have canker diseases or Verticillium Wilt often need to be fed yearly for many years to encourage more healthy growth.
"Healthy trees may need to be fed but not necessarily on a yearly basis."
Fall is also a good time to put down winterizing lawn fertilizer. The grass should still be green but no longer growing.
"Both the trees and the turf will take the fertilizer up and store it for next spring's growth," said Schuster. "It is better not to fertilize or under fertilize than it is to over fertilize. Over fertilizing may cause burning or make the plants more susceptible to some diseases. Be sure to follow all directions and precautions on the fertilizer product label."
Schuster noted that dormant pruning on many shrubs may be done if the plants have been through a freeze or several heavy frosts. Summer blooming shrubs are the plants that should be pruned during their dormancy for maximum health and flowering.
"Chose the correct pruning technique depending on the kind of shrub being grown," he said. "Single-stem shrubs should be headed back to a bud, branch, side branch, or trunk."
Multi-stem plants should be thinned. Remove the stems between one and three inches above the ground to reduce the risk of diseases and insects attacking stumps. Small, twiggy shrubs such as an Anthony Waterer spirea can be cut to the one-to-three-inch height once every five to eight years.
"You can also prune spring-blooming shrubs," said Schuster. "However, this reduces the number of spring blooms on the shrub if you are thinning--and all the flowers if the entire plant is cut to one inch."
Fruit trees and grapes should not be pruned in the fall. It is better to wait until late February or early March, he recommended.
"Large landscape trees can be pruned now," said Schuster. "However, if you have to leave the ground to do the pruning or you are removing branches with phone or power lines in them, hire a profession tree trimmer or arborist."
If spring bulbs have not been planted, do so right away so they can start to root before the ground gets too cold. Trees and shrubs may still be planted but there is a greater risk of the plants not surviving the winter.
"Mulch the plants with about two to three inches of organic matter to allow more time for the plant to root before the ground gets too cold also," said Schuster. "Avoid mounding the mulch up several feet like you see on some highway trees. Wet mulch against a tree trunk can cause trunk damage if it stays too long against the trunk."
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Source: Sharon Yiesla (847) 223-8627 Contact: Bob Sampson Extension Communications Specialist Phone (217) 244-0225; rsampson@uiuc.edu
Preparing Perennial Beds for Winter
Autumn is the time to prepare perennial flower beds for winter, said a University of Illinois Extension horticulture educator.
"In autumn, watering should be done on a continuing basis until the soil freezes and can no longer accept water," said Sharon Yiesla. "Keeping plants well hydrated helps to maintain a good root system. It is from this root system that the plant will re-sprout next spring."
Good watering, Yiesla noted, should consist of an inch of water every week between rainfall and irrigation provided by the gardener. Supplying that water in a good, deep, once-a-week watering is far more beneficial than sprinkling every day or two. A deep watering will encourage a deep, strong root system.
"Remove weeds from the garden before winter," she said. "Although these plants will not be growing in winter, they can act as an over-wintering place for various diseases and insects. Removal of the weeds helps to reduce certain pest problems for the following growing season."
As plants begin to decline and head toward their winter dormancy, gardeners should think about cutting the plants back to the ground.
"This activity may be spread out over a number of days or weeks since all perennials do not go into dormancy at the same time," Yiesla said. "As plants decline in appearance, they can be cut back to the ground. Since most perennials will re-sprout from the root system, there is no need to leave tall stubs of old stems in the garden. Cut stems down close to the ground.
"There are a few perennials that tend to be semi-evergreen and these may not need to be cut down until after winter has passed."
If the gardener chooses, cutting the plants can wait until spring. Some plants, when left in the garden can provide winter interest, act as snow collectors (for insulation), and may provide food for the birds. When choosing to leave plants uncut in the winter garden, the gardener must be willing to set aside some time in the spring to do the clean up.
"Applying mulch in the fall can help insulate the garden soil through the winter," she noted. "Before mulching, see how much mulch is left in the garden from spring applications. Overall, about two to three inches of mulch is sufficient."
Gardeners often mulch too early, applying mulch to soil that is still very warm, she added.
"Instead, wait until a couple of frosts have occurred and the weather is becoming consistently cooler," Yiesla said. "This signals that the soil is also cooling.
"Add mulch to obtain that two-to-three-inch layer on the ground around the perennials. Do not cover perennials with mulch or pile mulch around their bases as this may lead to excess water accumulation and rot the plant."
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