May is the prime time to give your plants a little TLC with some well-timed pruning. A quick trim now can set the stage for flowers that are bigger, brighter, and ready to impress.
Trust me, I’ve seen how the right cut can turn a mediocre bloom into a garden standout. These 20 plants need a little snip before the month’s over to ensure they bloom their best.
Skip the pruning, and you’ll miss out on the full potential of your garden’s brightest stars.
1. Snip Those Sleepy Roses
Nothing transforms a garden like properly pruned roses. Rose bushes need a good spring cleanup to remove any winter damage and stimulate gorgeous summer blooms.
Cut away dead or diseased branches, then shape the plant by trimming about 1/3 off healthy stems at a 45-degree angle just above an outward-facing bud.
Look for crossing branches that might rub against each other and remove the weaker one. Clearing the center of the plant improves air circulation, reducing the risk of fungal diseases that can plague these beloved flowers throughout the growing season.
2. Wake Up Your Hydrangeas
Garden experts agree that timing matters tremendously with these showy bloomers. Hydrangeas fall into two main pruning categories depending on whether they bloom on old or new wood.
For those flowering on new growth (like Annabelle or PeeGee varieties), late May is perfect for removing dead stems and shaping.
Be careful with mophead and lacecap types that bloom on old wood—only remove dead branches and spent blooms. A light touch now ensures those big, beautiful flower heads will make a spectacular showing when summer arrives in full force.
3. Freshen Up Lavender Mounds
Early bloomers deserve special attention as spring temperatures rise. Lavender plants benefit from a gentle but decisive pruning in May to prevent them from becoming woody and sprawling.
Cut back about one-third of the green growth, but never into the woody stems, as they won’t regenerate. Focus on creating a nicely rounded shape that will fill out beautifully as summer progresses.
Regular pruning keeps lavender compact and promotes more of those wonderfully fragrant purple flowers that attract beneficial pollinators and provide material for dried arrangements throughout the year.
4. Shape Those Butterfly Bushes
May offers the perfect opportunity for a serious cutback of these pollinator magnets. Butterfly bushes (Buddleia) grow rapidly and benefit from aggressive spring pruning to maintain an attractive shape and encourage more flowers. Cut stems back to about 12-24 inches from the ground, removing any dead or crossing branches.
The seemingly harsh pruning might look alarming, but don’t worry! New growth emerges quickly, producing more flowering stems than unpruned plants.
5. Revitalize Tired Clematis
Climbing beauties need strategic attention before summer arrives. Clematis vines fall into three pruning groups, but many summer-flowering varieties benefit from May trimming.
Group 3 clematis (those flowering after June on new growth) can be cut back to about 12 inches from the ground.
Group 2 varieties (large-flowered types blooming in early summer) need gentler treatment—just remove dead stems and trim back to a strong pair of buds.
The difference proper pruning makes becomes apparent when your fence or trellis bursts with spectacular blooms instead of a tangled mess of woody stems.
6. Rejuvenate Leggy Geraniums
Overwintered plants need special care to perform their summer best. Geraniums that survived indoors often become stretched and sparse, making May the perfect time for a rejuvenating trim.
Pinch or cut back leggy stems by about one-third, making cuts just above a leaf node to encourage bushier growth.
Remove any yellowed leaves or spent flower heads while you’re at it. The plants might look temporarily smaller, but they’ll quickly respond with fresh, compact growth and more abundant blooms throughout summer.
For potted geraniums, combine this pruning with fresh soil and slow-release fertilizer for spectacular results.
7. Groom Early-Flowering Shrubs
Flowering shrubs bring incredible color to spring gardens but need post-bloom attention. Forsythia, weigela, and mock orange produce flowers on old wood, making May the ideal time to prune after their spectacular spring show concludes.
Cut back about one-third of the oldest stems at ground level to encourage new growth. Shape remaining branches by selectively removing any crossing or awkwardly positioned stems.
Unlike some shrubs that resent pruning, these vigorous growers appreciate the attention and respond with more flowers next year.
8. Trim Back Fading Bulb Foliage
Spring garden stars need attention as their blooms fade away. Daffodils, tulips, and other spring-flowering bulbs should have their spent flower heads removed promptly, but the foliage requires patience. Wait until leaves turn yellow (usually by late May) before trimming them back to ground level.
During this waiting period, the leaves photosynthesize and store energy in the bulbs for next year’s flowers. Resist the urge to braid, fold, or cut green foliage, as this reduces the plant’s ability to prepare for next spring.
Once properly yellowed, a clean cut at the base keeps your garden tidy without sacrificing future blooms.
9. Refresh Tired Salvia Plants
Early-season performers need encouragement for repeat blooming. Salvia plants, with their vibrant spikes of blue, purple, or red flowers, benefit from a post-bloom haircut in May.
After the first flush of flowers fades, cut stems back by about one-third to encourage a second and even third round of blooming.
Make cuts just above a set of healthy leaves or a branching point. This practice not only stimulates more flowers but also keeps these perennials compact and prevents them from becoming floppy or splitting open in summer rains.
The bonus? Pollinators will thank you for providing additional nectar sources throughout the season.
10. Invigorate Evergreen Perennials
Year-round garden anchors need seasonal refreshment too. Evergreen perennials like lavender cotton (Santolina) and germander (Teucrium) benefit from a spring trim to maintain their compact form and encourage fresh growth.
Using sharp shears, remove about one-third of the previous year’s growth, cutting just above where new leaves are emerging.
Pay special attention to any winter-damaged sections, removing them completely. May pruning allows plenty of time for new growth to develop before flowering begins.
The result? Denser plants with more blooms and a tidier appearance throughout the growing season, plus less maintenance required later in summer.
11. Pinch Back Chrysanthemums
Fall bloomers need spring attention for spectacular autumn displays. Chrysanthemums benefit from early-season pinching to create fuller, more floriferous plants.
When stems reach about 6 inches tall in May, pinch off the top inch using your fingers or small pruners to encourage branching.
Repeat this pinching every 2-3 weeks until early July, then stop to allow flower buds to form. Each pinch might seem like you’re delaying flowering, but you’re actually multiplying potential bloom sites.
The difference between pinched and unpinched mums becomes dramatically apparent in fall—think dozens of flowers versus just a handful per plant.
12. Shape Flowering Vines
Climbing garden stars need direction and encouragement. Morning glories, black-eyed Susan vines, and other annual climbers benefit from a May pinching to promote branching.
When vines reach about 6 inches in length, pinch off the growing tip to encourage side shoots that will produce more flowers.
For perennial flowering vines like honeysuckle or trumpet vine, May offers the perfect opportunity to remove winter damage and thin out congested growth.
Cut back any wayward stems and train the remaining vines onto their support structure. Strategic pruning now prevents a tangled mess later while maximizing the summer flower show.
13. Encourage Bushy Petunias
Popular summer bedding plants benefit tremendously from early pruning. Petunias naturally tend to become leggy as they grow, with flowers appearing only at the ends of increasingly long stems.
Combat this by pinching or cutting back stems by about half their length in late May, just above a set of leaves.
The trimming might look drastic initially, but plants quickly respond with multiple new stems where each cut was made.
Regular deadheading throughout summer extends the flowering season, but this more substantial May pruning sets the stage for truly spectacular container displays and flower beds bursting with color rather than sprawling, sparse plants.
14. Manage Flowering Herbs
Dual-purpose garden plants need special attention for both beauty and flavor. Herbs like oregano, thyme, and sage produce lovely flowers but benefit from pruning to maintain vigorous, compact growth. Cut back about one-third of the previous year’s growth in May, before flower buds form.
For culinary use, regular harvesting serves as ongoing pruning. Snip stems just above a growth point or set of leaves to encourage branching.
Flowering herbs attract beneficial insects, but removing some flower buds concentrates the plant’s energy into leaf production for better harvests. The aromatic clippings can be dried or used fresh in spring cooking.
15. Control Rampant Groundcovers
Low-growing spreaders benefit from containment strategies in spring. Groundcovers like creeping phlox, sweet woodruff, and hardy geraniums can become overgrown or invade neighboring plants without regular maintenance. May provides the perfect opportunity to edge these enthusiastic spreaders and thin interior growth.
Use sharp shears to cut back by about one-third, especially where plants have flopped or become woody in the center. Many groundcovers respond to this treatment with fresh growth and a second flush of flowers.
The trimming also prevents them from smothering neighboring plants while maintaining the carpet-like effect that makes groundcovers so valuable in garden design.
16. Deadhead Spring Bloomers
Early performers need attention as their first show concludes. Pansies, violas, and other cool-season flowers often begin to look tired by May but can be rejuvenated with proper pruning. Remove spent flowers along with a few inches of stem rather than just picking off the faded blooms.
This more substantial pruning encourages new growth from the base and sides of the plant. Follow up with a light application of fertilizer to fuel the new flush of flowers.
While these cool-season bloomers will eventually succumb to summer heat, proper May pruning extends their season significantly, bridging the gap until summer annuals reach their peak.
17. Prune Spring-Flowering Trees
Ornamental beauties need attention after their spectacular shows. Flowering cherries, crabapples, and magnolias should be pruned immediately after blooming finishes in May.
Remove any crossing, damaged, or diseased branches, making clean cuts at branch collars rather than leaving stubs.
Avoid heavy pruning that removes more than 20% of the canopy in one season. Since these trees form next year’s flower buds in summer, May pruning allows plenty of time for new buds to develop before winter.
The reward for this timely attention comes next spring with a balanced canopy and abundant blossoms that aren’t crowded by excessive growth.
18. Refresh Potted Pelargoniums
Container favorites need regular attention to maintain their appeal. Pelargoniums (often called geraniums) benefit from pinching and pruning throughout the growing season, starting in May.
Remove any leggy growth by cutting stems back by about one-third, always making cuts just above a leaf node.
Don’t forget to deadhead spent flower clusters by snapping them off at the base of their stems. Regular removal of yellowing lower leaves keeps plants looking fresh and improves air circulation.
May pruning sets up these popular container plants for months of continuous blooming rather than short bursts followed by periods of sparse flowers.
19. Shape Summer-Flowering Spireas
Medium-sized shrubs need attention before summer arrives. Spirea varieties that bloom in summer (like ‘Goldflame’ or ‘Anthony Waterer’) flower on new wood, making May the perfect time for pruning.
Cut back all stems by about one-third to encourage dense, compact growth and maximum flower production. For older plants, remove a few of the thickest, oldest stems at ground level to rejuvenate the shrub.
20. Encourage Reblooming Daylilies
Garden workhorses benefit from strategic trimming for extended performance. Daylilies, particularly reblooming varieties, respond well to May pruning that removes spent flower stalks and tidies foliage. Cut flower scapes down to the base after blooming to prevent energy waste on seed production.
For daylilies with winter-damaged foliage, a light trim of leaf ends refreshes the plant’s appearance. Dividing overcrowded clumps in May also counts as a form of pruning that rejuvenates plants.
The combination of removing old growth and dividing when needed results in more abundant flowering throughout summer rather than a brief, disappointing show.