Extension Fall Garden Packet 08-1
Published: Aug. 26, 2008
NOTE TO EDITORS: This is the first of three University of Illinois Extension Fall Garden Packet installments. The second installment will be sent on Aug. 28 and the third one on Aug. 29. Thank you for your consideration. Bob Sampson, Extension Communications Specialist
August 26, 2008
Source: Greg Stack (708) 720-7520 Contact: Bob Sampson Extension Communications Specialist Phone (217) 244-0225; rsampson@uiuc.edu
A Peek over the Fence
When horticulturists go on vacation not only do they go to relax and have a good time They also seem to find, or make time, to wander into nurseries, botanic gardens or other places, in order to get their "plant fix," said a University of Illinois horticulture educator.
"Such is the case with this horticulturist who happened to visit several growers and suppliers to nurseries and garden centers," said Greg Stack. "While there, full advantage was taken to "peek over the fence" to see what was new and exciting.
"Here are a few things of note to look for in 2009. You may want to make room for these new introductions as they bring new colors, forms and performance to the garden."
Stack started with zinnias. New for 2009 will be a series of zinnias called 'Zahara'. They come in white and pink but also for the first time a scarlet and yellow. These are outstanding garden performers with very high disease tolerance to mildew. They grow to a neat mound 12 to 18 inches high and as wide. They are outstanding performers for the full sun landscape and once established are very drought tolerant with very low water needs. The single flowers are about two-and-a-half inches in diameter. 'Zahara' zinnias were chosen for use in gardens at the 2008 Olympics in Beijing.
"Just when you thought you had enough petunias to choose from along comes the 'Littletunia' series," he said. "This petunia is so unique it deserves to be put into the garden. It is an extremely low grower and very compact. It grows to about three to four inches tall and spreads to about 12 inches. It produces a profusion of very small flowers about the size of a dime. It comes in red, pink, red/white, and plum. It makes a great edging plant and works well in smaller containers where you don't want a petunia that may overpower other plants in the pot."
And what would a new garden season be without at least a few more coleus?
"Be on the lookout for 'Chocolate Mint' and 'Indian Summer,'" he noted. "Both of these varieties do best with a little light shade but will also tolerate bright light in which case the colors get more intense. 'Chocolate Mint' is a vigorous plant growing to about two feet tall. The leaves are a chocolate brown color edged with a soothing mint green. 'Indian Summer' grows to two feet tall and is a rich mixture of earth tones such as greens, reds, and browns. It is a very striking plant that is even richer in color when given a little bit of light. Both are great as bedding plants or in containers."
For those who like basil, Stack recommended a new basil that is great for use in the kitchen but also highly ornamental. 'Boxwood' Basil is very compact (12 to 18 inches tall), uniform and dwarf small-leaved basil that looks like a boxwood hedge. It almost tends to look rectangular and would make a great 'culinary hedge' in the garden.
"What about new shrub vines and roses?" he asked. "In the vine world, look for a breakthrough in the bittersweet world.
"Remember when you had to plant a male and female bittersweet plant in order to ensure berry production? Well, that is no longer the case with 'Autumn Revolution' Bittersweet. This plant produces flowers with both male and female parts, meaning all you need to plant is one plant for berry production. And what a berry production you will get. 'Autumn Revolution' is a vigorous vine growing to about 25 feet with large glossy green foliage. It will need a substantial support in the garden. As for berry production, extraordinary comes to mind. The berries are orange to red in large clusters with individual berries almost the size of small grapes. It has a very attractive and impressive fall display, quite an improvement for this native vine."
Two new roses are also worth looking at for 2009. 'High Voltage' is a shrub rose with double yellow flowers three to four inches in diameter. The plant is highly disease tolerant to black spot and hardy to zone 4. Blooms are held high on sturdy canes and are very fragrant. It has a vase-shape habit so it is good for back of the border. 'Kashmir' is another shrub rose new on the scene that resembles a hybrid tea rose with blooms that are velvety red. It has a rounded habit growing to about two feet tall, making it a good plant for a low hedge.
"Amelanchier or serviceberry is a great three-season plant," he said. "However, most are rather large and may not fit into small space gardens. With the introduction of 'Obelisk,' gardeners with smaller space can now include this great plant."
'Obelisk' grows to about 15 feet tall but is only four feet wide. This narrow habit is perfect for small space gardens. It will offer stems that are covered with white flowers in the spring followed by small orange/red berries in June and dark green circular leaves that change to red/orange in the fall. Birds love the berries.
"That's a little peek over the fence at what is headed your way next season," he said. "As with most gardeners, I'm sure you'll find room for your favorite."
-30- August 26, 2008
Source: Greg Stack (708) 720-7520 Contact: Bob Sampson Extension Communications Specialist Phone (217) 244-0225; rsampson@uiuc.edu
Rx for Tired Flower Beds--Cabbage and Kale
Flower beds going into the fall often look just a little bit tired. Annuals may have started to decline and gotten overgrown and perennials may not have a lot of color, said a University of Illinois Extension horticulture specialist.
"If that is the case with your flower beds, think cabbage and kale," said Greg Stack. "No, not the kind you eat but the kind you plant in the garden to offer brilliant color and unique habit well into the fall and early winter."
Ornamental cabbages and kales have been developed to fit the time slot when things may not be looking their best in late autumn and when you want color in early winter. While they may be called flowering cabbage and kale, it is not the flower that is prized but the colorful foliage. Ornamental cabbages look much like their vegetable garden relatives only they do not form heads while the kales tend to have a more fancy or cut leaf.
"Ornamental cabbage and kale do not tolerate summer heat and that is why they are best planted as fall garden annuals," he said. "If you want to grow your own from seed, it should be planted six to eight weeks before the first frost in the fall. Otherwise the next best option is to visit your local garden center. They usually start to show up after the mums start to arrive."
Using these plants as a fix for late-season color and planting them in early fall has several advantages. The white, pink, and red pigmentations for which these plants are noted do not appear until after several frosts, and then the color really starts to intensify when temperatures get below 50 degrees. And once they get acclimated to the garden, you can count on them to survive and provide color even when temperatures get as low as 5 degrees. So that means you might be seeing color peak through a soft blanket of snow.
"Just as with other plants, the larger the size pot the more you will pay for plants," he said. "However, this is one crop in which getting larger plants may pay off.
"When ornamental cabbage and kale gets rootbound in the pot, they tend not to get much larger once planted out in the garden. Since the goal of planting these plants is to achieve a solid mass of color, paying less for small plants usually requires planting more of them, and as a result it costs more to get the job done."
When planting ornamental cabbage and kale, plant so the lowest leaves are flush with the soil and the stem is buried. Because they are heavy users of water, keep them well watered in order to keep them looking at their best. Plants that dry out are not nearly as attractive.
"These fall garden stars are great for replacing worn-out annuals both in the garden and in containers," said Stack. "Use them as mass plantings or as edgings in the front of the border. They look great combined with fall ornamental grasses, asters, and dark-leafed sedums.
"While both ornamental cabbage and kale are edible they tend to be bitterer. Also, the pretty colors turn an unappealing gray when cooked. Ornamental kales often are used as a fancy garnish on plates. Look for plants in the garden center this fall and consider planting them in your garden to add a pick-me-up and provide dependable late fall and winter color."
-30- August 26, 2008
Source: Jennifer Schultz Nelson (217) 877-6042 Contact: Bob Sampson (217) 244-0225 Extension Communications Specialist e-mail: rsampson@uiuc.edu
Wooly Worms and the Weather
Despite the scientific evidence that discredits any super weather-predicting power for the wooly worm, people are very passionate about them, said a University of Illinois Extension horticulture educator.
"Several towns in the United States have their own wooly worm festivals," said Jennifer Schultz Nelson. "Banner Elk, North Carolina, hosts an annual festival complete with a wooly worm race. The winner is declared the 'official' predictor of winter weather."
Each fall, it's hard not to notice little wooly worms crawling across roads, sidewalks, and paths everywhere. Whereever they are going, they seem very determined. Many people wonder what they actually are. Do they stay as they are or morph into something entirely different in time? And just how do they forecast the winter weather?
"Different species of wooly worms are found all over the world," Nelson said. "The ancient Romans used the Latin term catta pilosa, literally "hairy cat," to describe them. The term caterpillar traces back to these early descriptions.
"The creatures we call wooly worms are, in fact, caterpillars, so their time spent as a wooly worm is limited. The United States is home to at least eight species of the hairy caterpillars that are commonly called wooly worms."
In central Illinois, the most common is the banded wooly bear or worm, Pyrrharctia Isabella. Following the pupal stage, the banded wooly bear emerges in its adult form, the Isabella tiger moth.
"Experts estimate around 260 species of tiger moths in North America," she said. "Their caterpillars share some degree of hairiness--from a few hairs to being completely covered in hairs, like the wooly worms.
"Tiger moths get their name from their bright coloration. Their colors are typically some spotted or striped combination of gold and black. Some species also have red, white, and gray colors interspersed as well. This Isabella tiger moth is a dull yellow-orange with some black spotting, and its first pair of legs has bright red-orange segments."
Each year brings two generations of banded wooly bears, or Isabella tiger moths. One is typically hatched in May, the other in August.
"Most people don't notice wooly worms in the spring and early summer, but they're around, feeding on various plants and growing," she said. "One reason we probably don't notice them is that essentially they're hermits, preferring solitude over socializing."
Another tiger moth larva, fall webworm, is far friendlier, and tends to congregate in large populations on their host plants.
"It is only in the autumn that most people notice wooly worms, and the worms are usually in a big hurry to get somewhere," said Nelson. "What's the rush? Each wooly worm is scrambling to find a warm nook or cranny in which to overwinter.
"Unlike other butterflies or moths, the wooly worm spends the winter as a caterpillar, not a pupa or chrysalis. The hairs covering their bodies are thought to offer some degree of insulation from cold winter temperatures. When the weather warms in the spring, the banded wooly worm becomes active again. They feed for a short time, then pupate, and emerge a few weeks later as adult Isabella tiger moths."
A lot of folklore surrounds the banded wooly worm, particularly related to its supposed ability to predict upcoming winter weather each fall.
"The typical banded wooly worm has sections of black hairs at each end, and a section of orange-brown hairs in the center," she explained. "Legend says that the more black on a banded wooly worm, the more severe the winter will be.
"Some folks have taken this to an extreme, and noting that there are 13 segments in a typical banded wooly worm, they argue that each segment represents one week of winter. Orange segments predict mild weeks, and black ones foretell bad winter weather."
Some people also insist that the thickness of the hairs is the predictor--thick hair equals a bad winter, sparse hair a mild one. Another legend says that the direction a wooly worm is found traveling is a hint about the coming winter. If the wooly worm is traveling north, count on a mild winter. If he's headed south, get ready for a long, cold winter.
"Research has shown repeatedly that the colors or hairs of wooly worms have no bearing on weather the following winter," she said. "Larvae hatched from the same clutch of eggs reared under one set of environmental conditions will show a range of hair thickness and colorations, from fully orange to fully black.
"This variation in a constant environment is a strong argument against wooly worms being able to predict the weather. There is genetic segregation for color and hair thickness present in the wooly worm population. This segregation would make it nearly impossible to visually sort out any environmental influence if it did exist."
Still, the wooly worms have their defenders.
"People come from miles around to participate in the Banner Elk wooly worm festival races," Nelson noted. "Some bring wooly worms they collected; others prefer to buy a wooly worm from one of the 'breeders' who bring their best racing stock to the festival. I guess you can sell just about anything!
"Illinois had its first official wooly worm festival in Camargo in 2006. Will wooly worm breeders be far behind? Time will tell."
-30- August 26, 2008
Source: Matt Kostelnick (847) 981-1104 Contact: Bob Sampson Extension Communications Specialist Phone (217) 244-0225; rsampson@uiuc.edu
Sowing Grass Seed
Late summer or early fall is the best time to sow grass seed, said a University of Illinois Extension horticulture educator.
"Why? One of the main reasons is weed competition," explained Matt Kostelnick. "When planting grass seed in the spring, many weed seeds will be germinating around the same time, thus competing with the new grass seedlings for water, nutrients, light, and space.
"This makes establishing new turf difficult, especially since weed control is difficult with emerging grass seedlings."
Plus, for the home gardener, grass seeding in late summer or early fall means one less chore to have to do in the spring. It is also one that can help fill the late dog days of summer.
"There are two main reasons for sowing grass seed," he said. "One reason is to start a new lawn from scratch on bare seedbed. The other is to fill in bare spots and/or thinning areas of the lawn. This is overseeding.
"Both practices are best done in northern Illinois in mid-August to the first week of September, mid-August to mid-September in central Illinois, and September for southern Illinois."
Most herbicides are too strong to be applied when grass seedlings are young, he noted. Conventional pre-emergent herbicides, for example, would not work because they would prohibit weed seeds from germinating as well as the desirable grass seeds from germinating. Also, keep in mind that these are seedlings; thus they are weak and vulnerable.
"Soil and air temperatures are ideal in late summer and early fall, which encourages rapid seed germination and root growth," he said. "A disadvantage of sowing grass seed in spring is summer heat creeping up on the young grass seedlings. Summer heat slows the root and shoot growth of cool-season grasses, evaporates water quickly, and can foster rapid weed growth.
"It is particularly important for the grass to develop a deep root system in order to handle summer heat stress. A shallow, undeveloped root system will cause significant stress to grass during the summer. With late summer/early fall plantings, summer heat will be waning, and the grass will have plenty of time to develop a strong root system before the following year's summer heat."
Establishing a strong turf stand is important in developing a healthy lawn, Kostelnick noted.
"If a decent lawn is developed in the fall, the following spring will be started with a healthy, established lawn," he said. "Additionally, since the grass is established, it will be developed enough to handle normal pesticide applications such as crabgrass pre-emergent herbicides in spring as well as all other regular lawn practices.
"This is not the case with spring-sowed turfgrass."
-30- August 26, 2008
Source: Sharon Yiesla (847) 223-8627 Contact: Bob Sampson (217) 244-0225 Extension Communications Specialist e-mail: rsampson@uiuc.edu
Fall Garden Wrap-up
Wrapping up the garden for the season is not the one-day project many people assume, said a University of Illinois Extension horticulture educator.
"This process is usually done over the course of several weeks, since houseplants summering outdoors may need to come inside in September and some outdoor gardening activities may extend into mid- or late October," said Sharon Yiesla.
Home gardeners might find it helpful to follow a "to-do" list for fall prepared by Yiesla.
"First, bring in houseplants that have summered outdoors," she said. "They should come in when night temperatures consistently fall into the lower fifties--and this could be as early as September."
When moving the plants inside, she cautioned, try to avoid abrupt changes in light and temperature. Also check for insects. Cleaning the pot or repotting the plant may be enough to control pests. Some plants that have outgrown their pot may need to be repotted. Pruning may be in order for plants that have grown vigorously while outside.
"Next, clean up vegetable gardens and annual flower beds," she said. "First, harvest all usable vegetables and annual flowers. Any leftover debris can be tilled into the soil or placed into compost piles. Be sure to clean up weeds as they can harbor diseases and insects.
"Add compost and other organic material to enrich the soil and mulch beds to prevent erosion during the winter."
Third, perennial flower beds need to be cleaned up. Remove weeds to eliminate overwintering sites for insects and diseases. After a couple of frosts, mulch the perennial bed with two to three inches of mulch. The tops of the plants can be cut back now or in the early spring, depending on when you have the time. New perennials can be planted in September, and established perennials can be divided.
"The fourth 'to-do' task is tree and shrub maintenance," she noted. "Prune deciduous trees after they go dormant or in the early spring. Prune late-summer and fall-flowering shrubs after they go dormant. DO NOT prune spring-flowering shrubs in the fall as you will remove the flower buds.
"Trees and shrubs can be fertilized after they go dormant. Continue regular watering as long as the ground is not frozen. This is especially important for evergreens."
Finally, there are a number of miscellaneous activities in the garden that are appropriate in the fall season.
"These include planting spring-flowering bulbs from mid-September through mid-October, cleaning garden tools so they will be ready next spring, seeing to the proper storage of seeds, fertilizer, and garden chemicals, and draining and storing water hoses," she said.
-30- August 26, 2008
Source: Martha Smith (309) 836-2363 Contact: Bob Sampson (217) 244-0225 Extension Communications Specialist e-mail: rsampson@uiuc.edu
Winter Perennial Gardens
Your garden's "bones" may provide visual interest and variety from December through March, said a University of Illinois Extension horticulture educator.
"Does your garden have good 'bones'?" said Martha Smith. "This is a winter-design buzzword. Which plants offer a sense of permanence and structure in your garden during the winter? With the big show of flowers out of the way, your garden is reduced to its purest form.
"The skeletons of woody plants provide interesting designs against a winter sky."
During the fall season, many gardeners begin their winter preparation ritual--enjoying fall foliage colors but dreading the inevitable raking to come. Neighbors seem to compete with each other, raking every last leaf off their lawns and then attacking garden beds.
"With blower or special rubberized leaf garden rake in hand, they begin the assault," Smith said. "They pull out the annuals and snip back perennials, leaving a barren 'moonscape' to look at all through the winter.
"In our landscape beds, why not take a lesson from nature where leaves remain where they fall and many plants offer wonderful winter attributes?"
These features are the "bones" of the garden.
The silhouettes of evergreens and the skeletons of woody plants contrast with the blinding white of a snowy January day. Between these "bones," seed heads, berries, and bark can provide the subtle variety that the color-starved eye in January pounces on, she said.
"After a snowfall, interesting mounds and shapes appear as snow covers Blue Fescue (Festuca cinerea) or Purple Dome aster (Aster novae-angliae 'Purple Dome') or any plant in the garden," she said.
To ensure better footing, stone walkways should be cleared of leaves. "But the rest can stay where they fall in a garden bed," Smith recommended. "The only items to cut back are those with known insect or disease problems, or plants that re-seed in areas where they are not invited such as Northern Sea Oats (Chasmanthium latifolium), Blackberry Lily (Bleamcanda chinensis), Black Eyed Susan (Rudbeckia hirt var. sulvantii 'Goldsturm'), Tovara (Persicaria virginiana var. filliformis 'Painter's Palette'), and Purple Cone-Flower (Echinaceas puruprea) to name a few.
"If you want these plants to mingle with their neighbors, leave them up to re-seed and provide food for the birds."
Ornamental grasses are beautiful in the winter. Miscanthus species such as "Gracillimus," "Morning Light," "Malepartus," "Blondo," and "Purpurascens" are just a few that stand guard over gardens in the winter.
"Sedum spectabile seed heads offer a beautiful burnt sienna to winter borders," said Smith. "Sometimes autumn winds knock over the heavy flower heads and force many gardeners to cut them back in the fall.
"Leave them if you can. You will enjoy the view in January."
While cutting everything back in the garden is a tool for control, Smith wonders if it is best for the plant.
"For certain plants like Peonies, there is a benefit--removing old foliage reduces future disease problems," she said. "But for many perennials, advantages outweigh disadvantages. By not cutting back, fallen leaves can hold on better and insulate plants during bitter cold days and nights. This natural mulching prevents desiccation from strong, cold winter winds that otherwise would pull moisture from the ground and perennial roots.
"Snow is an excellent insulator but if it doesn't have something to accumulate over it, it keeps on blowing in the wind. Leaves and old plant debris will hold the snow. When the spring thaw arrives, all this moisture will be around your plants rather than melting down the drain."
But, she added, large, plate-sized Sycamore or tough oak leaves can smother plant material. Some gardeners run them through a shedder or collect them in their lawn mower bags and return this mulch to the garden beds.
"The problems arise in the spring when these large leaves block air movement to the soil surface," she said. "If you leave these leaves on, make sure you are out in the early spring to stir them up. This allows air to reach the soil."
Spring clean-up will involve cutting back perennials and removing heavy accumulations of leaves and winter debris.
"You eventually have to do the work," Smith said. "But these tasks are often easier in the spring since plant remains are brittle and usually rake off easily."
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