Garden Calendar for April

Turnin the Soil

Turning the Soil

April brings warmer weather, longer days, and the first chance to do some outdoor gardening. Since a hard frost is possible into May, it's still a little too early to plant new annuals. But some varieties of hardy vegetables can be sown outdoors towards the end of the month, and it's not too soon to get things cleaned up in preparation for the gardening season ahead.

Shrubs and Trees

  • Fertilize woody plants before new growth begins.
  • Plant and transplant trees and shrubs as soon as the soil is dry enough to be worked. Bare root specimens should be planted before they break dormancy; balled-and-burlapped and containerized stock can be planted anytime during the growing season. After planting don't forget to water well and mulch!
  • Always read plant or nursery labels and instructions to determine the optimum growing conditions for new shrubs and trees. Improper location is the main reason plants fail to thrive.
  • Prune evergreens (except pines). Keep the pruning cuts within the green (foliage) parts of the plant. If cutting goes back into bare branches it is sometimes difficult or impossible for the plant to re-grow from the old growth.
  • Pines will produce new candle growth from terminal buds later this spring. In some cases, a pine that looks brown now may look much better when the new growth emerges. Take a wait and see approach with pines; do not prune them now, as the terminal buds will be removed and no new growth will occur on that branch.

Lawn Care

  • Rake your lawn to open up the soil and remove debris. If the lawn feels spongy under your feet, you may need to de-thatch it.
  • Prevent crabgrass and other grassy weeds before they start by applying a pre-emergent herbicide before the ground temperature reaches 55°F (i.e., before the yellow forsythia stops blooming and before the lilacs blossom). Crabgrass is an annual weed that re-seeds itself each year. It is difficult to control once it is up and growing, but a pre-emergent herbicide will kill the seed as it germinates. If you plan to reseed bare areas in your lawn, use a pre-emergent specifically labeled for new lawn establishment.
  • Avoid applying nitrogen-based fertilizers when your lawn is dormant and has not greened-up; the growing stimulant provided by the nitrogen could end up encouraging the growth of broadleaf weeds or other unwanted grasses in your lawn. Allow the grass to green up, grow, and be mowed once or twice before applying fertilizer in late April or early May.
  • The best method of applying fertilizer is to use the half-rate setting suggested on the fertilizer bag and go over the lawn twice in a crisscross or grid pattern. This will reduce the chances of creating dark and light green stripes in the lawn.
  • Products that combine fertilizer with a broadleaf weed (i.e., dandelions, thistles, creeping charlie, etc.) killer work through the leaf tissue, so control is achieved only when broadleaf weeds are actively growing. Wait until late spring, usually when the dandelions are blooming, to treat your lawn with this type of "weed-and-feed" product.
  • Snow mold may be highly visible as matted, crusty looking patches in your lawn. If your lawn is plagued with snow mold,
    • Mow your lawn shorter in the early spring (about 2" instead of 2.5") to help warm and dry the soil and roots. Just don't forget to raise your lawnmower back to its normal setting (about 2.5") by the first of May.
    • Fertilize at half the normal rate. Set your spreader at the setting described on the bag and then close the opening to half that size. Apply the other half of the fertilizer 3 weeks later. Then go back to your regular program.
    • Put down a lawn fungicide containing Daconil, Immunox, or Bayleton after the first or second mowing and every 2 weeks until the disease is gone.
  • You may have grubs if there are lots of birds feeding on the ground in your yard; if you have patches of brown grass that pull up easily; or if you've spent the time and energy to dig down a foot and have found adult grubs. There are several ways to treat grubs:
    • Systemics (Mach II or Merit) are granular and are applied on the surface of your lawn in the spring. The products will work about 12 weeks in the roots of the grub's favorite food.
    • Contact killers are most effective. Look for a product listing Bendiocarb in the ingredients and ALWAYS follow label directions when applying.
    • Milk Spore is the most natural and long-term method of grub control. Milk Spore is applied 3 times a year for 2 years, or 2 times per year for 3 years.
  • As soil temperatures approach 55° F, consider reseeding thin, bare spots in your lawn. Be sure to use mulch, as heavy spring rains have been known to wash grass seed away.
  • Confused? Make it easy on yourself. Let Reds prescribe a custom fertilizer / crabgrass / weed control / grub program for you.

Perennials, Annuals, and Bulbs

  • Fertilize perennials and bulbs. Use either a balanced fertilizer or one high in phosphorus to promote strong root growth.
  • Did you get a lily for Easter? Extend the bloom period by placing the plant in a location that gets moderate, indirect light and cool temperatures (65°F to 70°F). Remove the anthers (yellow pollen-bearing structures) from the center of the flowers, and keep the soil consistently moist. If you want to save the bulb for planting outdoors, continue to water regularly once the flowers have faded and feed with a regular houseplant fertilizer. The leaves will eventually yellow and die back to soil level. Plant the bulb outdoors once all danger of frost has past.
  • Place seedlings in cold frames towards the end of the month to harden off.
  • Remove mulch from roses, perennials, and bulbs shortly after new growth has started to allow air and light to reach the plants, promote hardiness, help the soil and foliage dry out, and avoid diseases that thrive in wet conditions. Keep plastic sheeting or mulch handy to re-cover plants if a late freeze is predicted.
  • Hostas and perennials should be divided before they leaf out. If they are not divided every few years, the number of blooms will be reduced.

Fruits and Vegetables

  • Know when to turn the soil. If the soil is still wet and clumps together, then tilling may cause soil compaction, drainage, and aeration problems later on in the season. If the soil crumbles when you work it around in your hands, then it's okay to till.
  • Once the soil is tillable, very hardy vegetables that can withstand freezing and hard frosts can be planted outdoors towards the end of the month. Crops in this category include asparagus, beets, carrots, lettuce, onions, peas, parsley, parsnips, potatoes, rhubarb, and spinach.
  • Think of where your vegetables were planted last year and try to rotate your crops; do not plant the same vegetable in the area it was planted last year.
  • Don't wait too long to remove mulches from strawberries. Once the leaves have emerged from under the straw and yellowing is evident, pull the mulch away from the tops of the plants and tramp it down between the rows.
  • Divide rhubarb plants as soon as the soil is tillable. Dig up the whole crown and break off the young side shoots, keeping as many roots intact as possible. Transplant the mother plant back in the original hole and plant the shoots in a full sun location. Harvest the young plants lightly, if at all, the first year.
  • Fertilize all fruits except strawberries using a high nitrogen fertilizer. Soft berries will form if strawberries are fertilized early.

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