May Gardening Tips for the Northeast
May is a busy month in the garden. As you prepare to dig into the growing season, double-check your to-do list against our monthly chore calendar.
Pots to Welcome Spring
Give your entry an easy facelift by filling pots with colorful flowers and herbs. Make designing them easy by choosing flowers that complement the color of your home's exterior.
Early in the month, plant flowers that won't wilt during chilly spring nights. Pansy, snapdragons, sweet alyssum, or fragrant flowering stock all thrive in cool weather and grow well in pots.
Be cautious hanging baskets of frost-tender annuals for Mother's Day. Fuchsia, bacopa, and viola will shrug off cool nights, but tender annuals like sweet potato vines, impatiens, and nasturtium won't withstand even a light frost.
Herbs can hold their own in early spring containers. Snip leaves to season dishes and create salad dressings.
Test Garden Tip: Mediterranean herbs such as sage, rosemary, lavender, and thyme, tend to grow especially well in unglazed terra-cotta pots, which help keep roots on the dry side.
Lettuce and other greens tend to grow particularly well in the cool weather of April and May. These crops are easy to grow -- and allow you to make your own salads from fresh, homegrown leaves!
If rabbits are a problem, try growing your lettuce in containers. Simply tuck lettuce seeds or seedlings into shallow pots; place pots in a location that receives up to a half-day sun. Plant lettuce at tighter-than-recommended spacing -- when seedlings start to crowd each other, thin them and eat the thinnings.
Go for the gourmet look and select a blend of lettuce types, including romaine, butterhead, and leaf. With leaf lettuces, plant a variety of hues to craft colorful salads.
Maximize harvests using the cut-and-come-again technique. Begin by picking outer leaves only from young plants. As plants mature, cut off every other plant just above soil, leaving a 1-inch stem stub. A small pair of scissors works well for this task.Fertilize lightly with liquid feed after harvest. The stubs will resprout.
Harvest remaining uncut plants when leaves are large enough, leaving a stem stub to resprout. You'll get several harvests using this technique.
Test Garden Tip: Lettuce and other greens love cool weather -- but crops like tomatoes and peppers don't. Wait to set heat-loving vegetables -- including eggplants, cucumbers, squash, pumpkins, or okra -- into the garden until all danger of frost has passed.
Tackle weeding while invaders are small. Hand-dig offenders with an Asian hoe, putty knife, or other favorite tool. Weeds pull easiest when soil is wet.
Wait to prune spring-flowering shrubs (such as lilacs, mock oranges, weigelas, many types of viburnum, etc.) until after blooms fade. Prune immediately after flowering to avoid hindering next year's show.
Give the compost pile a turn or two after spring rains start. Turning the pile even a little helps work moisture throughout, which jump-starts spring decomposition.
Test Garden Tip: Wait to mulch planting beds and vegetable gardens until later this month -- when soil has warmed. Don't cover soil until after self-sowers have sprouted and there's a need for mulch to retain soil moisture and shade weeds.
Care for Perennials
Divide summer- and fall-flowering perennials before plants exceed 6 inches tall. If spring rains are scarce, don't forget to water newly transplanted divisions.
Add a shovelful (or two) of compost to roses, clematis, butterfly bush, and delphinium. You'll be rewarded with more blooms and bigger plants.
Start pinching garden mums as soon as shoots are 4 to 6 inches long. Remove the last inch of growth until early July and you'll enjoy bushy plants loaded with flowers in fall.
You can also pinch back other late-blooming perennials such as sedum to keep them more compact in autumn.
Test Garden Tip: Insert stakes now to prevent flopping later with plants like peony, aster, or false sunflower. To avoid accidentally spearing dahlia tubers, add stakes at planting time when you still tell where the tubers are.
Mow Like a Pro
Time mowings so you're not removing more than one-third the length of grass blades at any one cutting.
A mulching mower chops grass finely so you can leave clippings on the lawn -- no need to bag.
Keep your mower blade sharpened to avoid tearing grass and creating entry wounds for disease.
Use a half-moon edger to freshen lawn edges on planting beds and along paths. Slice cleanly through grass, holding the edger at a right angle to turf.