Pruning is a crucial May gardening task, but knowing which flowering plants to trim, and how to do it properly, can make all the difference to your blooms come summer. Although May signals the start of the blooming season for numerous plants, it is also the time when we need to be a little ruthless and cut back certain varieties that have already flowered or are currently doing so. Giving some plants a bit of care now through pruning or deadheading will benefit their shape and future growth.
Expert Advice for May Pruning
Noah Mabey, senior gardener at Thornbridge Hall, stated that May is "the best time" to begin pruning several key plants, but cautioned that "it has to be done carefully." He highlighted that plants such as ribes (flowering currant), forsythia, spiraea, and choisya can all be trimmed back now — but only gently. To tackle this job, Noah advised starting by "deadheading spent flowers" before you "prune around a third of the older woody stems" — this maintains the plant's health without going too far. Here are four essential plant varieties to get pruning before May draws to a close.
Tender Perennials
Once the threat of frost has passed, May is the ideal moment to cut back tender perennials such as penstemons, fuchsias, and salvias. Noah said, "These plants respond really well to a cut back after frost risk has gone. It encourages strong new growth and better flowering later in the season." He also recommends trimming any unusually long or 'leggy' stems, cutting back to a bud to encourage more controlled growth. "I also advise gardeners to remove any reverted growth on variegated shrubs to maintain their colour and structure. It's a simple job, but it keeps plants looking their best."
Climbing Plants
As climbing varieties such as honeysuckle develop, Noah urged gardeners to secure new stems and continue "deadheading to extend flowering." He said, "Try tying stems horizontally to encourage more flowering shoots and reduce wind damage." It is also vital to inspect anything growing up walls — whether fruit trees, roses, or climbers — and carefully release stems that might have become trapped behind wires. Tackling this now is far simpler while the growth remains pliable.
Rhododendrons and Wisteria
Rhododendrons reach their finest in May, but once the flowering period ends, they require deadheading and gentle pruning. Noah said, "Removing spent flower buds helps the plant put energy into next year's blooms instead of seed production. Wisteria also needs attention after flowering. Once it has finished blooming, deadhead and shorten long shoots to encourage flowering spurs. If you're still training it, now is the perfect time to tie in new growth."
