Spring Gardening Tips - U of I Extension

News Release

Spring Gardening Tips

This article was originally published on April 4, 2010 and expired on June 1, 2010. It is provided here for archival purposes and may contain dated information.

With warmer weather predicted, gardeners are itching to get into their gardens, said a University of Illinois Extension horticulture educator.

"So grab your shovel, rake and hoe and get ready for spring with the following tips," Ron Wolford urged.

Save the mesh bags that oranges come in and use them this summer to dry herbs and gourds. Save pantyhose to enclose individual veggies like melons, corn, cabbage, cucumbers and small pumpkins to protect from birds and insects. Tie the pantyhose off at both ends of the veggie to keep insects out. The pantyhose will stretch with growth and dry off quickly after rain.

"Save orange juice and tuna fish cans to use as barriers around newly transplanted plants to protect them from the cutworm," he said. "Cutworms will chew through the stems at soil level. Cut both ends from the cans and push cans about an inch into the soil around the plants.

"After two to three weeks, the cans can be removed because the stems will have thickened enough to withstand any cutworm damage."

Wolford suggested making homemade seed tapes for small seeds like carrots, lettuce and beets by following these directions:

Cut plain paper or copy paper into long one-inch wide strips

Mix flour and water to the consistency of gravy to make glue.

Using a small watercolor paintbrush, pick up a small dot of glue, and then touch the brush to a seed and place seed with glue on the paper.

Space the seeds on the paper according to the directions on the seed packet.

Air dry the tapes, roll them up and store in a plastic sandwich bag.

"Avoid damping off disease when starting seeds," he added. "This fungus disease kills plants at the soil line, causing them to collapse."

To head the disease off, use a sterile soil medium. Sterilize pots and containers in a 10 percent bleach solution. Sink the containers in the solution for a few minutes and rinse with water. Keep the temperature around 65-70 degrees F for best germination and provide bottom heat if possible. Most of all, avoid overwatering. Allow the soil to dry before watering and always drain saucers under containers after watering.

"Don't rush the growing season," he cautioned. "The frostfree date for Chicago is around April 25 near the lake and May 15 away from the lake. The term frostfree means that there is still a 50-50 chance of frost on the frostfree date.

"Be prepared for late spring frosts. Cover tender plants with row covers, cardboard, blankets, hot caps, or newspaper. Do not use metal or plastic for protection; they can conduct cold to plants. We have had frost as late as Memorial Day."

In the spring, never work your soil when it is wet. Tilling or digging when the soil is wet will cause it to dry into concrete-like clods. Pick up a handful of soil before digging and squeeze. If it crumbles easily, it is ready to be tilled. If it doesn't crumble, it is too wet. Allow the soil to dry for a couple of more days and test again before digging.

Buy healthy vegetable transplants, Wolford said.

"Leaves and stems should be green and healthy without any signs of yellowing or browning," he noted. "Yellowing or browning leaves may indicate an insect or disease problem.

"Gently remove transplants from their tray and check the root system. Roots should be white with visible soil. Transplants with brown dead roots should not be purchased. Check for insects such as whiteflies or aphids. Be sure to gradually introduce your transplants to the outdoor environment over a period of days, especially plants grown and purchased in a greenhouse. When you do plant, water your transplants in with a starter fertilizer that is high in phosphorus that helps to promote root development."

Harden off cool-season vegetable transplants before exposing them to cool temperatures, wind and sun. Gradually introduce them to the outdoor environment over a seven- to ten-day period.

Wolford recommended using a water-soluble starter fertilizer to water in vegetable transplants. A starter fertilizer is high in phosphorus, which helps to promote good root development, getting the plant off to a good start. The most common water-soluble starter fertilizers like 5-10-5, 10-52-17 or 8-32-16 should be used at the rate of one to two tablespoons per gallon of water. Use one to two cups of the fertilizer to water around the roots of the plant.

"When your lettuce begins to bolt, consider leaving the plants in the garden," he said. "The bolted leaf lettuces with their flowering stalks make a striking display. Red-leaf lettuces are particularly spectacular. Pull the lettuce in late summer for a second planting for the fall."

Cut back the foliage of ornamental grasses to about four to six inches. Not removing the foliage will delay the warming of the crown of the plant and will slow new growth. Ornamental grasses can be divided in the spring, especially if the center of the plant has died out or if it has overgrown its space.

"Divide perennials in the spring," he said. "Divide plants when flowers get smaller, when the center of the plant dies out or when the plant outgrows its space. Dig around the plant and lift the clump out of the ground.

"Break the clump into sections. Larger sections will re-establish quicker than smaller sections. Keep the clumps moist until ready to plant."

Do not plant Zoysia grass, even though you will see glossy ads touting its benefits, said Wolford. Zoysia grass is a warm-season grass more suitable for lawns in St. Louis. It is dormant and brown in the spring and fall. It also forms thatch and has to be de-thatched every year. Zoysia grass is planted using plugs that may take three to four years to establish.

"Don't apply a nitrogen fertilizer to your lawn too early in the spring," Wolford said. "Research has shown that in the early spring grass roots thrive, forming a network of deep roots. Deep roots will help your lawn survive hot, dry summer weather.

"Applying fertilizer too early will promote grass shoot growth at the expense of root development. If you usually apply a pre-emergent crabgrass killer combo with fertilizer in April, try to find a crabgrass killer without fertilizer to apply, and wait until mid-May to put down a nitrogen fertilizer to the lawn."

Spring is the time to kill creeping charlie. Creeping charlie has kidney-bean-shaped leaves and blue flowers. It is most susceptible to weed killers when it is in flower in the spring. It tends to establish itself in parts of the lawn that are too shady for grass. Control with hand removal or hoeing before it sets seed.

Prepare lawn for the mowing season. Rake away all twigs and debris. Have the lawn mower blades sharpened, replace the spark plugs and change the oil. Apply the first application of fertilizer in early May. Have your lawn core aerified. This process will pull up small cores of soil to the surface. Core aerification helps to reduce thatch problems, soil compaction and poor drainage. Machines can be rented. Make two trips across the lawn, the second trip perpendicular to the first. An average of 15 to 20 aeration holes per square foot is recommended.

"Seed bare spots in the lawn," he said. "Dig up the soil and add a starter fertilizer. Sprinkle on a good seed mix of bluegrass and fescue. Rake lightly to mix seed with soil. Tamp to assure seed-soil contact. Keep well watered for two to three weeks until the seed has germinated."

Spring is prime feeding time for rabbits. There are several methods of control that you can use.

"Almost any type of garden center sells rabbit repellents and sprays," he said. "These may work for a short period of time, but will have to be applied often, especially after rains. Remember that new growth since the initial spraying is not protected."

The most effective protection against rabbits is a chicken-wire fence. It may not look good, but it works. Wolford recommended the following:

Purchase a three-foot high roll of chicken wire

As you set up the fence, bend the bottom six inches outward at a 90 degree angle.

Bury this under two inches of soil.

You want to make sure that you follow these steps because this will keep the rabbit from burrowing under the fence. The remaining 2-1/2 foot fence is high enough that even the strongest rabbits can't hop over. Since rabbits won't usually eat squash, tomatoes, or potatoes, they can be planted outside the boundaries of the fence, but if rabbits are really hungry they will almost eat anything.

Extend the life of your Easter lily by placing it in indirect light. Bright sunlight may burn the flowers and shorten the bloom time. Keep at temperatures of 65-70 degrees F. Remove the lily flowers as soon as they die. Plant outside in a sunny spot as soon as danger of frost is past. Water thoroughly. Fertilize with a 5-10-5 fertilizer. The old top will die back and new shoots will emerge. The plant will flower in July or August.

"Groundcovers can be mowed to remove winter-burned foliage," Wolford said. "Raise the mower to its highest setting, fertilize and water after mowing to ensure rapid re-growth."

Source: Ron Wolford, Extension Educator, Horticulture, rwolford@illinois.edu

Pull date: June 1, 2010