Spring Gardening Packet
March 2, 2005
  • /Crop Sciences
University of Illinois Extension Spring Gardening Packet

NOTE TO EDITORS: This is the first of three installments of University of Illinois Extension's Spring Gardening Packet. This installment contains six articles. The second installment will be transmitted on March 8 and will contain four articles. Six articles are included in the final installment to be sent on March 15. Please call me if you have questions. Thanks for your consideration of this material. Bob Sampson, Extension Communications Specialist, (217) 244-0225, rsampson@uiuc.edu

March 1, 2005

Source: Ron Wolford (773) 233-0476 Contact: Bob Sampson Extension Communications Specialist Phone (217) 244-0225; rsampson@uiuc.edu

U of I Extension Gardening Web Sites

Spring not only brings warmer temperatures, melting snow, flowers, and weeds but also questions from the home gardener, said Ron Wolford, University of Illinois Extension urban gardening educator based in Chicago.

"What is the best way to take care of those brown patches in my lawn? Should I cut back the foliage of my tulips right after they bloom? What kind of tree is best for my front yard? When should I plant broccoli transplants?" he said. "The answers to these and other questions can be found on U of I Extension's Hort Corner web site."

Bulbs and More, Wolford noted, provides information on the basics of bulb care including what to do after the bulbs bloom. The web address is: http://www.urbanext.uiuc.edu/bulbs .

Thirty straightforward and informative fact sheets on lawn care are available at Lawn Talk. Information covered ranges from lawn grasses for northern Illinois to lawn repair and renovation to fertilizers to dealing with white grubs. The address is: http://www.urbanext.uiuc.edu/lawntalk .

" Watch Your Garden Grow is a comprehensive guide to growing, storing and preserving 34 common vegetables," said Wolford. "Information provided for each vegetable includes recommended varieties, when to plant, spacing and depth, general care, how to harvest, common problems and solutions, preparing and serving, home preservation and recipes."

The address for Watch Your Garden Grow is: http://www.urbanext.uiuc.edu/veggies .

A novice gardener looking for the basics will want to visit A Taste of Gardening. It is located at: http://www.urbanext.uiuc.edu/tog .

Help in selecting the perfect tree for your landscape can be found at Selecting a Tree for Your Home. The site sorts trees by size, exposure, tolerance and use. It includes a search function that allows users to select characteristics such as size and exposure that are specific to their yards. The address is: http://www.urbanext.uiuc.edu/treeselector .

"Before you start your spring garden chores, it might be helpful to visit one of these web sites," said Wolford. "A little research and preparation will make your early season gardening a pleasant experience."


March 1, 2005

Source: James Schuster (708) 352-0109 Contact: Bob Sampson Extension Communications Specialist Phone (217) 244-0225; rsampson@uiuc.edu

To Seed or Not To Seed

When spring arrives, many people think they need to over-seed their lawns even though it is probably not necessary, said James Schuster, University of Illinois Extension horticulture educator based in Cook County.

"In general, you do not need to over-seed a lawn that is just thinned-out due to the winter," he said. "Instead, consider core aerification--only after several mowings--and/or fertilizing."

Over-seeding, he explained, is done to diversify the turf to help reduce disease problems or to adjust for a change in sunlight.

"If a tree died or was removed so there is more sun, the shade-tolerant fescue may need to be replaced with a more sun-tolerant grass," he said.

Some people want to roll their lawn because it is lumpy after the winter. Lumpy lawns are more likely to occur in low maintenance lawns. Rather than rolling the lawn which increases soil compaction and, therefore, more diseases and insect problems, Schuster recommends considering mowing higher or doing light fertilization.

"As the lawn thickens, the lumpiness will be reduced or disappear all together," he said. "Over-seeding does not reduce lumpy lawns for any length of time, if at all, since adequate fertility is necessary for a thick lawn that is not lumpy."

Spring seeding should be done as early in the season as possible. Early spring seeding reduces competition from the weeds which will try to germinate in the spring.

"Spring seeding can be done in landscapes where there is no turf, where this is an erosion problem, though additional work must be done to keep seed in place on erosion sites, or where there are large dead patches or large areas that need renovation," Schuster said. "However, if possible try to seed or over-seed in the late summer, late August to mid-September. At this time, grass seed germinates faster because soils are warm and the air is generally cool. There are also fewer weeds that will germinate at that time of the year."


March 1, 2005

Source: James Schuster (708) 352-0109 Contact: Bob Sampson Extension Communications Specialist Phone (217) 244-0225; rsampson@uiuc.edu

When To Plant

Come late April and early May, many people get anxious to begin planting gardens but a University of Illinois Extension horticulture educator cautions that several factors need to be considered before taking to the garden.

"Whether or not you should plant depends on the weather, the type of plants you want to put out, and where you live," said James Schuster, who is based in Cook County. "Homeowners living near Lake Michigan can plant sooner than homeowners living out near the Fox River in Kane County or in the Joliet and Kankakee areas."

While the term "frost-free" may be familiar to most, Schuster believes there is some confusion about its actual meaning.

"When first heard, many gardeners think these words mean what they say--no more frost. However, frost-free actually means there is a 50-50 chance of frost on the designated frost-free day," he said.

"Near Lake Michigan, the frost-free date is usually considered to be April 25. Somewhere between one and three miles from the lake and out to Interstate 294, the frost-free date is May 1. West and south of Interstate 294, the frost-free date is May 5."

Plants that can be planted on or before the frost-free date have to be cold-hardy, plants that can tolerate frost and even some freezing weather. Plants that are tender or warm-weather plants should not be planted until three weeks after the frost-free date. Even waiting three weeks after the frost-free date allows for about a 5 percent chance of frost.

Vegetables that are frost-resistant include: leaf lettuce, onions, peas, spinach, Irish potatoes, Brussels sprouts, cabbage, cauliflower, broccoli, carrots and radishes. Examples of annual flowers that tolerate frost are: alyssum, pansies, violas, flower kale/cabbage, snapdragons, straw flowers, calendula, cornflower and dusty miller.

Warm-season or tender vegetables are beans, tomatoes, peppers, squashes, sweet corn, cucumbers and melons. Warm-season or tender annual flowers are rose moss, petunias, impatiens, marigolds, geraniums, begonias, dianthus, celosia, coleus, sunflowers and cosmos.


March 1, 2005

Source: Susan Grupp (630) 653-4114 Contact: Bob Sampson Extension Communications Specialist Phone (217) 244-0225; rsampson@uiuc.edu

Annuals to Brighten Garden

Annual flowers can color up a yard from spring through fall and can be used to fill-in voids of a newly-planted perennial garden, soften the edge of a walkway, or plant in front of a fence, said Susan Grupp, University of Illinois Extension horticulture educator based in DuPage County.

"When gardeners talk about annuals, they usually mean flowers," said Grupp. "Annual flowers are among the most versatile and rewarding group of plants to grow. Annuals can be used in many ways. They can be grown with perennials, shrubs and even under trees. They are also easy to grow in containers and window boxes.

"Annuals can add interest to a vegetable garden, too."

Flowering annuals complete their life cycle in one season. Compared to other plants, they produce an abundance of continuous blooms, which they hope will lead to lots of seed and a guarantee of their future.

"The proper growing conditions are important for annuals," she said. "Many annuals prefer full sun--at least six hours of sunlight. Others need a shady spot. Pay attention to soil conditions and wait until the weather warms for transplanting annuals into the garden."

Grupp said that annuals are sold in small cell packs, flats and individual pots. A flat or tray of annuals is priced at a lower cost per plant than if purchased as individual packs. Recently, annuals have been offered in larger pot sizes, such as four-inch and six-inch pots. These larger--and more expensive--plants have become quite popular.

"When shopping for annuals, be sure to pick out the healthiest ones you can find," she said. "Look for well-shaped plants with strong stems and leaves. Avoid tall, spindly plants. Instead, buy the shorter, stockier ones. Unless the plant is supposed to have unusual coloration, stems and leaves should be a healthy shade of green.

"Read the plant tags found in the packs. They have valuable information such as the plant height and spread and flower color, light and drainage requirements. Follow the spacing recommendations to avoid overbuying and overspending."

Grupp said it is best to pick plants that have not yet formed their flowers.

"A flat of cell packs deteriorates quickly, so be sure to time your purchases with your planting date," she said. "Store your transplants in a protected spot until you are ready to plant. They will dry out and need to be watered frequently."

Grupp recommended preparing the garden by digging in a complete fertilizer, such as 13-13-13, at a rate of 1.5--2.0 pounds per 100 square feet.

"Just before planting, water your transplants and allow the excess water to drain," she said. "Then, gently remove the plants from their pack and inspect the root ball. Often the root system is circling the pack and looks root-bound. If this is the case, gently roughen or 'tickle' the roots. This is a very important step and will encourage roots to stop circling and begin to grow into the surrounding garden soil.

"If roots fail to grow outward, plants will languish all season long."

Transplants should always be planted at the same depth they were grown.

"Gently tamp the surrounding soil and water immediately," said Grupp. "A starter fertilizer may be used at this time. Most annuals will benefit from a soft pinch to remove flowers or flower buds.

"These steps will encourage roots to develop and help plants get established in the garden."


March 1, 2005

Source: Sharon Yiesla (847) 223-8627 Contact: Bob Sampson Extension Communications Specialist Phone (217) 244-0225; rsampson@uiuc.edu


Pruning may seem like a natural thing to do in late winter and early spring, but a University of Illinois Extension horticulture educator cautions that it depends on what you want to prune.

"Some woody plants can be successfully pruned in late winter/early spring, but others should be pruned at another time," said Sharon Yiesla, who is based in Lake County. "Deciduous trees--those that lose their leaves in the winter--can be pruned while they are dormant. This is actually a good time, since it is easy to see the framework of the tree. Seeing the framework makes it easier to decide what needs to be removed."

Pruning trees that have been in the landscape for a while consists mostly of maintenance pruning. She recommends removing branches that have been damaged by fall and winter storms, any branches that are crossing one another and branches that appear to have been attacked by disease and insects during the growing season.

"After that has been done, remove branches that will help improve the shape and form of the tree," she said. "Do not cut just to be cutting. Always prune with a purpose."

Pruning shrubs in late winter/early spring takes a little thought, she noted.

"Shrubs that will bloom in the spring should NOT be pruned now," she said. "They formed their flower buds last summer and, if they are pruned now, spring flowering will be greatly reduced.

"Spring-flowering shrubs should not be pruned until after they are finished flowering. Shrubs that bloom mid-spring-to-summer can be pruned in March since they will not form their buds until spring time."

When pruning shrubs, it is best not to just "give them a hair cut," Yiesla said.

"Too often, shrub pruning consists of lopping off the top few inches of the shrub. Take time and do it right. Prune selectively."

There are two main types of cuts to make, she added. Thinning cuts are made to remove a branch at the point where it emerges from the ground. Cutting out older branches to the ground will not only stimulate new growth but will start to lower the height of the shrub.

"Doing this type of pruning on a yearly basis helps keep shrubs from becoming too tall while maintaining a natural shape," she said. "This type of pruning is perfect for shrubs with several medium to large stems emerging from the ground, like old-fashioned lilac and red twig dogwood."

The other type of cutting is known as 'heading back.'

"With this cut, only a portion of a branch is removed back to a side branch or bud," Yiesla said. "Making a number of heading back cuts at different heights helps to open the shrub to sunlight and air circulation, which can reduce disease problems and enhance future flowering.

"As you look to prune shrubs, remember that good pruning is often a combination of both thinning cuts and heading back cuts."

Yiesla said that pruning cuts do not need to be painted or sealed.

"Just be sure to make good, clean cuts with sharp tools," she said. "Do not leave stubs as these will not produce new growth and may be entryways for disease and insects during the growing season.

Your cut should be made near the bud, since this is the area from which new growth will emerge."


March 1, 2005

Source: Sharon Yiesla (847) 223-8627 Contact: Bob Sampson Extension Communications Specialist Phone (217) 244-0225; rsampson@uiuc.edu

Selecting a Tree

If you're thinking of planting a tree this spring, it is worth taking some time to select the right one, said a University of Illinois Extension horticulture educator.

"A little research can result in the right tree for your property and landscape," said Sharon Yiesla, who is based in Lake County. "A good place to start is University of Illinois Extension's Tree Selector web site, located at: http://www.urbanext.uiuc.edu/treeselector/ ."

Cold hardiness is an important factor to consider in tree selection, she noted. The size and form of the tree should also be considered.

"Ask yourself three questions," Yiesla said. "What will the height of the tree be at maturity? What will be the spread--width--of the tree at maturity? Will the mature tree be in balance with the house or will it dwarf it? Is there enough room in the landscape to allow the tree to attain its mature size without sacrificing its natural form?"

Conditions existing at the planting site will affect the selection process. The pH of the soil, moisture and drainage conditions, and the amount of sun available in the yard should be taken into consideration. Select a tree that can grow in the conditions available in your yard, she recommended.

"All trees require maintenance. Some have higher needs than others. Think about how much work you intend to put into the maintenance of the tree," said Yiesla. "When selecting a tree that fits the amount of maintenance you can give consider the following: are disease or insect problems common? Is the wood strong or is it prone to storm damage? Is the tree untidy, producing litter such as fruit, seeds or twigs? Does the tree produce large quantities of seed, leading many seedlings?"

The ornamental features of the tree--flowers, fruit, bark, fall color, attractive summer foliage, and the form of the plant--should also be considered.

"What is important to you?" Yiesla said. "Make a list, but keep it realistic. There are some trees that provide beauty in more than one season, but many do not."