Provide Water for Migrating Birds
Migrating birds are on their way through the Midwest, so make sure to provide water. A gentle dripper in a shallow birdbath will attract warblers, tanagers, orioles, and buntings to the yard. Make sure to keep the birdbath clean and the feeders well stocked.
Cut Back Ornamental Grasses
Cut back ornamental grasses as early in the month as you can manage. They are attractive left standing over the winter, but the foliage should be cut back to about 4 to 6 inches in spring before the new growth resumes. Leaving the old foliage can delay growth by as much as three weeks.
Prune Spent Lilac Blossoms
After lilacs bloom they will benefit from a light fertilization and pruning. Prune off the spent flowers and trim back any diseased or crossing branches. Make sure they are well mulched and given an inch of water a week. Every few years remove some of the oldest stems as close to the ground as possible and thin out the younger wood in the center of the plant. Next year you should have plenty of beautiful blossoms.
Spray Dormant Oil On Fruit Trees
When those precious warm days appear in April, be ready to spray fruit trees with dormant oil for insect control. Dormant oil goes a long way toward keeping populations of aphids, mites, and other insects in check. There is even some evidence that the oil may help protect against fungal diseases.
Watch for Cutworms
When setting out transplants, be ready to prevent cutworm damage. These caterpillars chew tender stems and the plants then fall over and die. Cultivate soil lightly to expose caterpillars that hide just under the soil and then destroy. Put cardboard collars around transplants until they have time to harden a bit.
Don't Work Wet Soil
Don't be tempted to get into the garden when the soil is too wet. Working or walking on wet soil compacts it and makes it hard for roots to penetrate. Take a clump of soil in your hand and squeeze. If it oozes water, walk away. If it stays in a tight clump, walk away. If it breaks apart easily, get to work.
If your houseplant has roots growing through the drainage holes, roots on the soil surface, smaller than normal new leaves or if it wilts between waterings, consider repotting. Plants recover best when in active growth, so do it now before putting it out for the summer.
Perennials can be divided now. Signs that a plant needs dividing include: flowering is reduced and flowers are smaller, the center of the plant dies out leaving a hole with all the growth around the edges, the plant loses vigor, the plant starts to flop or open up needs staking, or it just may have outgrown its bounds.
Rhubarb will begin showing later in the month. Harvest while plants have robust stems and put the excess in the freezer. Simply chop and put in a freezer bag for use in rhubarb bread and cakes. When stems become slender, stop harvesting and wait until fall. It's not necessary to remove flower stalks from plants.
Set up Cold Frames
Even if there's still snow on the ground, put cold frames over garden beds to start warming the soil. You can even sprinkle spinach and kale seeds on the snow and they will get a very early start. Use recycled windows, window well covers, or anything with a clear top as the covers for your cold frames.
Transplant Seedlings Early
If you've started seeds indoors, transplant the seedlings into individual pots when they produce two sets of true leaves. Increase the light and begin fertilizing with a weak fertilizer or fish emulsion solution. Keep fluorescent lights only a few inches away from the tops of the plants for stocky, healthy growth.
Start Garden Clean-up
Enjoy the periodic warm days by getting some of the spring tasks out of the way early. Gently remove dead foliage from around perennial crowns (no need to remove it entirely). Cut back to the ground all perennials and ornamental grasses that were left standing for winter interest.
Don't do Anything to Emerging Bulbs
Bulbs that begin to send up green shoots when the weather is prematurely warm will usually not be harmed by late frosts. There may be a bit of tip damage, but the flower buds are still protected beneath the soil and will bloom later just fine.
Prune on Warm Days
When you get the occasional warm day, get out and prune. However, be selective about which trees you prune. Avoid pruning trees whose sap runs freely in warm weather such as elms, maples, and birches. If pruned in spring they will "bleed" sap profusely. This won't harm the trees, but it is unsightly. Prune these trees when temperatures are very cold or wait until late June.
Soak Bare Root Plants Before Planting
Soak bare-root perennials, shrubs, and strawberries in a bucket of warm water before planting. Choose your planting site carefully, and dig a hole big enough to accommodate all the roots without crowding. Fill the hole after planting with the same soil you removed, and water well to remove any air pockets.
Wait on Summer Bulbs
Don't be too quick to bring out summer bulbs that you've started indoors. Frost and cold will damage them quickly. Wait until the weather has settled into warmer nights in May. Keep in a sunny windowsill until then, and don't forget to keep them evenly moist.
Even though it may seem early, put your perennial stakes in place. The spring will come on quickly and it's impossible to stake after the plants are six inches tall without damaging them. Collect twiggy branches and insert them in the ground just outside the crown for the most natural looking staking system.
Begin hardening off transplants of cold-weather vegetables such as broccoli, cauliflower, cabbage, and Chinese cabbage. After hardening, these plants can go into the garden even though you may still have several frosts. Transplant on a cloudy, calm day if possible.