In this most unusual of springs, we’ve been told to stay home. But that doesn’t mean we can’t go outside, and with time on our hands, our yards and gardens beckon.
Lawns are turning green, and perennials are poking their heads out of the soil. But think before you grab the rake or start planting melon seeds outside.
The danger of April in the garden, lovely though it is, is doing too much too soon. Nature has its own schedule, and curbing our enthusiasm will pay off later.
It’s a Minnesota ritual to mark spring with a vigorous lawn raking and application of fertilizer and crabgrass preventer. Be careful. If the lawn is wet — if you hear sucking sounds when you walk, if you can see your footprints, or if the grass looks brown and sodden — it’s too soon to rake. Let the grass dry, and when you do rake, do so gently so you don’t risk pulling up roots.
Fertilizing should wait until May. Crabgrass preventer, which is often combined with fertilizer, can be applied between mid-April and mid-May. Put down too early, it loses its effectiveness. One natural guideline is to apply crabgrass pre-emergent when the lilacs are almost ready to bloom. That usually means the ground is warm enough for crabgrass to sprout.
Don’t prune oaks — it’s not safe again until October. And unless you’re willing to lose this year’s blooms, don’t prune spring-flowering shrubs like lilacs and spirea now. They should be cut back immediately after blooming.
Gardens can be raked, and soil amendments like compost can be added now. But again, watch the moisture. If you’re getting mud on your boots or soil seems to be clumping into balls rather than crumbling as you work it, it’s too wet. Walking on wet soil will compact it and make it difficult to work when it dries. Come back later to dig or hoe.
Clean up perennials
So what can impatient gardeners do now? It’s cleanup time for perennials. Cut ornamental grasses back, first targeting early varieties like Karl Foerster feather reed grass that send up new growth at the first signs of warmth. Rake the garden lightly to collect dried leaves from tough perennials like hosta or daylilies; prune perennial stems from plants like sedums that can be uprooted if you rake.
If you left perennials with sturdy stems like asters, Joe-Pye weed and cup plant standing, be aware that bees may have overwintered their young in the stems by laying eggs inside them. If you want to protect those pollinators but still clear the garden, cut the stems and pile them in a corner of the yard until mid-June, when the new bees will have emerged.
Prune and shape hydrangeas. Varieties like Annabelle can be cut almost to the ground, and they will be sturdier after being cut back. Panicle hydrangeas like Quick Fire also bloom on new wood, but the stems are strong. You can cut branches back by a third to half or hardly at all if you want them to grow tall. For varieties like Endless Summer, wait to see where leaves emerge on branches, and then prune out dead wood.
Plant cool-crop veggies
Cold-weather vegetables can be planted now. Peas, radishes, carrots, arugula, kale, beets and lettuce can be sown directly in the spring garden. Vegetables that are usually planted as transplants like Brussels sprouts, cabbage, broccoli and cauliflower also can be planted outside, as can asparagus crowns. All can take a frost.
We still have time to start warm-weather vegetables from seed indoors. Planted now, peppers and tomatoes will be ready to go outside when the ground is warm. Though eager gardeners sometimes think getting these tender plants into the ground will result in an earlier harvest, they will sulk in cold soil and possibly die. If you want to play it safe, hold off on planting tomatoes in the garden until at least mid-May, and plant peppers in late May.
Don’t bother sowing seed from crops like cucumber, melons or zucchini indoors. You’ll get sturdier plants by sowing these fast-germinating seeds outdoors in mid-May. But if you want, you can plant annuals like marigolds and zinnias indoors now and they’ll be ready for the garden when the danger of frost has passed.
While most perennials are barely showing yet, early spring is an ideal time to divide tough plants like hosta. The small shoots mean you can split plants without damaging leaves, and they’ll look good even this summer.
Lastly, if you hunger for color now, buy a pot of pansies. They’re among the toughest flowering plants we have and will take temperatures down into the upper 20s without much damage. If it gets colder than that, shelter them in the garage or porch overnight.
Mary Jane Smetanka is a Minneapolis freelance writer, a Hennepin County Master Gardener and a Minnesota Tree Care Advisor.