Gardeners, it’s time to test your mettle. If temperatures are cooperating, the merry, merry month of May may be your busiest until September, with planning, planting and patio projects to lead the way into summer.
Don’t be fooled by a late frost: Find out the mean freeze date in your area, and be sure soil is warm and workable — not too wet, not too dry — before putting tender plants in the ground.
Bulbs
Get those showy summer sprays of color started by planting bulbs of dahlia, lily, tuberous begonia and gladiolus.
Plant a few “gladdie” corms every week from now until early July for continuous summer cuttings.
- As their blooms fade, remove the flowers from tulips and daffodils and give them a dose of fertilizer. But leave those leaves where they are: They’re needed to produce next year’s buds. Peonies, too, will be hungry for fertilizer now.
- Got mums? From now until the beginning of July, you can make chrysanthemums bushier and more productive if you pinch a half-inch off of each stem when they’re 6 or 7 inches high.
Annuals
Early in the month, get a jump on flower planting with hardy annuals such as dianthus, petunias, snapdragons and pansies.
- If another frost threatens to sneak up on you, cover annuals overnight with thin burlap or newspaper.
- Most summer-flowering annuals can also be put in the ground now.
- Hang mixed baskets of fuchsias, geraniums and impatiens when the evenings warm up, and plant zinnias, lobelias and marigolds in the ground or in containers.
- When you’re safely in the no-frost zone — probably midmonth or a bit later — you can set out those six-packs of seedlings to harden them off before transplanting.
With any project, 80 percent of the work is done in the planning stage. We have simple checklists to help you get organized and make sure you’re prepared for every step along the way. Download them now for FREE:
Perennials
As the shoots of your old friends start peeking up through the soil, give them a light dose of fertilizer. Then head for the nursery to start selecting this season’s new perennials, many of which can be planted now if you’re sure Jack Frost has left town.
- There’s still time to plant the early birds such as primroses, coral bells, candytuft and saxifrage.
- In mild climates, start adding summer-flowering plants such as phlox, daylilies and delphiniums.
Lawn Care
If you haven’t done so already, assess the needs of your lawn now.
- Toss the moss, thatch and weeds.
- Aerate, feed and overseed to get rid of bald patches.
- Around mid-month, feed grassy areas with an even coat of high-nitrogen fertilizer.
- Unless spring showers are on their way, follow up with a good thirst-quenching dose of water.
- Anxious mowers, get out your measuring tape: When grass reaches 3 1/2 to 4 inches, bring out your tuned-up machine and let ‘er rip, leaving grass 2 1/2 to 3 1/2 inches high. A bit of extra height is good for its health, leaves shorter clippings (leave them in place to nourish the lawn) and cuts down on weed growth.
Vegetables
As you’re planting your vegetable garden, consider planting times as well as plant compatibility.
- In most climates it’s safe now to seed or plant hardier vegetables such as beans, peas, potatoes, lettuce, carrots, corn and chard.
- When you’re sure the soil is thoroughly thawed and warm (at least 60 degrees), go ahead and sow cucumbers, squash, melons, peppers, tomatoes and other tender annuals.
- Plant celery and cucumbers near your bean starts — they make good neighbors!
- Beans also get along well with peas, corn and potatoes, but keep them away from “aromatic” vegetables such as leeks, garlic, onions and shallots.
- Carrots, tomatoes and lettuces also like each other’s company — just be sure not to mix them with dill.
- Seeds of corn, pumpkins, squash, beans and melons can be sown directly into the ground now.
- If you sow vine crops for later transplant, use peat pots. At planting time, bury the whole pot so fragile roots don’t become damaged.
Planting
Shop for new plants as well as replacements of plants that didn’t make it through the winter, then transplant them when the soil warms up to 60 degrees.
- If you’re transplanting seedlings, introduce them gradually to their new environment to harden them off: Set them outdoors for longer and longer periods for a week or so before planting. Choose sheltered, shady areas at first, and work up to sunnier, breezier spots.
- You can buy and plant new trees and shrubs in May. Whether you purchase them in a container or they’re burlapped, their planting holes should be twice the circumference of the root ball.
Pruning
Pruning needs vary by climate zones.
- In cooler climates, May is the month to finish up your pruning duties on sap-oozing shrubs and trees; waiting until June can cause new growth to appear. Without a chance to mature, new growth won’t survive the winter.
- In milder climates, such as the Pacific Northwest, you’ll want to hold off on pruning evergreens until early June.
Weeding
In many areas, weeds have already begun flowering and seeding all that rich soil you’ve prepared so carefully.
- Nip weeds in the bud now, or get ready for some extra workouts this summer — and for up to seven years to come.
- If you use sprays to control weeds, especially morning glory and other resistant pests, be sure to choose a warm day without wind.
Fertilizing
Fertilizer is your garden’s friend. Don’t neglect to feed your little green ones.
- Start using a liquid fertilizer on recently set-out annuals after they’ve had a chance to get established.
- In mild climates, trees and shrubs such as rhododendrons, azaleas, camellias, roses and junipers can still take fertilizers for a while to come.
- Use rose fertilizer or an all-purpose garden fertilizer on roses, perennials and deciduous and annual trees and shrubs. In most climates, new growth should now be popping up on roses. If you don’t see signs of life at or above the graft, the bush may have kicked the bucket.
- Beware of overapplying fertilizer, which can be fatal — or at least cause leaf burn.
- After applying, give fertilizer a thorough watering-in.
Pest Control
The slugs crawl in, the slugs crawl out … and so do all those other persistent garden pests.
- Make it a last call for as many slugs as possible: Set out stale beer in shallow saucers or jar lids, especially around tender transplants. Slugs will drink, get drunk, fall down and drown. Or pick slugs by hand. Whatever your method, today’s slug war will reduce their numbers later in the season so the vegetables you sow will make it to table.
- Give aphids their walking papers: Hit them with a heavy dose of hose water, or wipe aphids off plants, then saturate problem areas with a spray of insecticidal soap.
- You can also use insecticidal soap to reduce damage on plants suffering from ash plant bugs.
- If you find tent caterpillars in tree branches (they’re especially fond of crabapple and fruit trees), prune out the limbs and destroy the cocoons.
Preparing your Patio
If you’re expecting a warm Memorial Day weekend, early May is a great time to get your patio picture-perfect for entertaining.
- Spruce it up with an easy-to-build wall lattice or trellis for clematis, climbing roses, kiwi or even hops.
- Finally ready for a striped table umbrella? Shop for this first, then choose container plantings to complement its colors.
- Container plants and trees can be moved around to create a variety of colorful seating borders.
- To cozy-up outdoor cocktail parties, break the ice with a chimenea, or potbellied clay fireplace.
- Dress nearby trees in strings of lights for evening entertaining.
There’s still plenty of time before summer for bigger projects: Add a flagstone path, create a water element, build a wraparound bench, or add a stone or rail enclosure around your deck or patio.
Almost June? Just Want to Keep Going?
Don’t worry, we’ve got a fresh checklist for you of the many June gardening tasks too, jump over to our June Gardening Checklist now!
thewriteDuffy
At home, April is a mom, wife, and DIY darling. Among other home projects, she helped her husband Dan renovate their 1986 bungalow and is currently designing and decorating the 2023 custom home they are building themselves. Professionally, April is a writer, author, and online marketer with 15 years of experience writing for newspapers and magazines, building online authority websites, and publishing books.
With any project, 80 percent of the work is done in the planning stage. We have simple checklists to help you get organized and make sure you’re prepared for every step along the way. Download them now for FREE: