Some perennials can get a little wild if you don’t keep them in check—I learned that the hard way. What started as a neat, tidy garden turned into a tangled mess by midsummer.
A bit of smart pruning made all the difference and brought everything back to life. I’ll show you which plants need a trim and exactly how I handle mine without going overboard.
If your garden’s ever looked more chaotic than charming, this list should help.
1. Lavender
Left unchecked, those fragrant purple spikes will eventually grow woody and sprawling, with bare patches in the middle. The plant loses its compact, attractive shape that makes it so garden-worthy.
Prune lavender back by one-third after flowering, avoiding cutting into old wood. For rejuvenation, cut back by half in early spring. This encourages bushier growth and prevents the leggy, open-centered look that makes older plants appear neglected.
2. Russian Sage
The silvery-blue clouds of Russian sage quickly turn from dreamy to droopy without intervention. Stems flop outward creating a messy, sprawling appearance that can overtake neighboring plants.
Cut back stems to about 6 inches above ground in early spring before new growth appears. Consider installing plant supports early in the season. Selective mid-summer pruning helps maintain its shape and prevents the plant from splitting open in the middle.
3. Yarrow
Yarrow’s flat-topped flower clusters look stunning initially but quickly become ragged as they fade. Without pruning, the stems weaken and sprawl outward, creating an untidy mound with a hollow center.
Deadhead spent flowers regularly to encourage reblooming and prevent self-seeding. Cut the entire plant back by half after the first flush of flowers fades. In early spring, remove any winter-damaged stems and divide overcrowded clumps every 3-4 years.
4. Catmint
The soft, billowy growth of catmint turns from charming to chaotic as stems elongate and flop over. What starts as a neat mound transforms into a sprawling mess that smothers neighboring plants.
Shear plants back by half after the first flowering to promote a second bloom and maintain shape. Consider the Chelsea chop in late May to create bushier growth. For severely overgrown plants, cut back to 2-3 inches above ground in early spring.
5. Coreopsis
These cheerful daisy-like flowers produce non-stop blooms that eventually turn brown and scraggly. The once-compact plant spreads outward, developing a messy, unkempt appearance with fewer flowers.
Regularly deadhead individual spent blooms to encourage continuous flowering. When plants look tired, shear back by one-third to stimulate fresh growth. Cut the entire plant back to basal foliage in late fall or early spring to maintain its compact form.
6. Salvia
Those striking purple spikes eventually fade to brown, creating an eyesore in your garden. Without pruning, the plant develops a leggy, open habit with fewer flowers concentrated only at the stem tips.
Cut back flower stalks once blooms fade to encourage a second flush. Shear the entire plant by one-third after main flowering period. For woody varieties, prune in early spring, removing about one-third of the old growth while avoiding cutting into woody stems.
7. Sedum
Those charming succulent rosettes and flower heads eventually become top-heavy and prone to splitting open from the center. The once-upright stems splay outward, creating a messy, fallen-over appearance.
Pinch back stems by one-third in late spring (the “Chelsea chop”) to create bushier growth. Remove spent flower heads in late winter rather than fall to provide winter interest. Divide overcrowded clumps every 3-4 years to rejuvenate plants and prevent center die-out.
8. Shasta Daisy
After their cheerful blooming period, Shasta daisies develop brown, spent flower heads and floppy stems. The once-tidy clumps become sprawling and unkempt with bare spots in the center.
Deadhead regularly to extend the blooming period and prevent self-seeding. Cut back stems to basal foliage after flowering finishes. Divide crowded clumps every 2-3 years in spring to maintain vigor and prevent the hollow center that makes plants look neglected.
9. Echinacea
Those beautiful coneflowers eventually develop dark, dried seed heads that can look messy. Without pruning, plants become leggy with fewer blooms concentrated at the top of increasingly taller stems.
Deadhead spent flowers to encourage continued blooming, unless you want to attract birds with the seeds. Cut back the entire plant to about 4 inches above ground in late fall or early spring. Divide crowded clumps every 4 years to maintain vigor.
10. Phlox
Tall garden phlox becomes increasingly leggy with sparse foliage at the base and flowers only at the top. Spent blooms turn brown and mushy, especially during rainy periods.
Cut back stems by one-quarter in late spring to encourage branching and stronger stems. Deadhead spent flowers promptly to prevent self-seeding and encourage reblooming. Thin out one-third of the stems in early spring to improve air circulation and reduce powdery mildew issues.
11. Asters
Fall-blooming asters grow increasingly tall and floppy throughout summer, often requiring staking by bloom time. Without pruning, they develop a sparse, leggy appearance with flowers only at the top.
Pinch back growth by one-third in late May and again in late June (the “Chelsea chop”). This creates bushier plants with more flowers. Cut back stems to about 2 inches above ground after flowering or in early spring to maintain neat appearance.
12. Bee Balm
Bee balm’s square stems tend to grow tall and floppy, creating a wild, untamed appearance. After flowering, the spent heads turn brown and scraggly, detracting from the garden’s appearance.
Pinch stems back by one-third in late spring to encourage branching and reduce height. Deadhead spent flowers promptly to extend the blooming period. Cut plants back to ground level in fall and divide every 2-3 years to prevent center die-out.
13. Delphinium
The tall, majestic flower spikes eventually fade, leaving behind brown stalks that detract from the garden’s beauty. Secondary growth often appears sparse and weak without proper pruning.
Cut flower stalks back to the ground after blooming is complete. This encourages a second, smaller flush of flowers in fall. Remove all foliage to ground level in late fall. Divide plants every 3-4 years in spring to maintain vigor.
14. Veronica
The striking blue spikes of Veronica eventually turn brown and seed heads form, creating a messy appearance. Plants develop a sprawling habit with bare centers if not properly maintained.
Deadhead spent flower spikes promptly to encourage reblooming and prevent self-seeding. Shear plants back by half after the main flowering period to promote fresh growth. Cut back to basal growth in late fall or early spring.
15. Baptisia
False indigo develops a rounded, shrub-like appearance that can become unwieldy without pruning. After flowering, the seed pods turn black and rattle in the wind, which some find unattractive.
Cut back by one-third after flowering if you don’t want the decorative seed pods. For a neater appearance, prune the entire plant back by half in mid-summer. Avoid dividing due to its deep taproot; instead, control size through regular pruning.
16. Hollyhock
These cottage garden favorites produce tall flower stalks that eventually become brown and unsightly. The large leaves often develop rust spots, adding to the messy appearance.
Remove spent flower stalks at their base to maintain a tidy appearance. Cut away any diseased foliage promptly to prevent spread. After flowering completes, cut the entire plant back to a rosette of basal leaves to encourage fresh growth.
17. Peony
After their spectacular spring show, peonies develop seedpods and the foliage eventually turns yellow and unsightly. Without pruning, the plants become susceptible to diseases and look unkempt.
Deadhead spent flowers back to a strong leaf node to prevent seed formation. Cut stems at an angle just above a bud to encourage branching. In fall, cut all foliage to ground level and remove it to prevent disease carryover to the next season.