Using the Chelsea Chop for Native Plants
Native plants have a reputation for being “wild”, but that doesn’t mean they can’t be managed for aesthetics. Simple maintenance techniques can prolong flowering, minimize flopping (plant stems toppling sideways under their weight), and promote new growth throughout the growing season. In this post, I’ll focus on one gardening technique known as the Chelsea chop.
Spotted Joe Pye Weed (Eutrochium maculatum) produces many flowering stems after a Chelsea chop.
What is the Chelsea chop?
The Chelsea chop name derives from the traditional late spring cutting at the Chelsea Flower Show in London. Herbaceous perennials, plants with annual foliage and root systems that survive through winter, are cut to one-third or one-half their size. This encourages plants to continue devoting energy to flowering, helping prevent early dormancy during summer stress.
In London, the Chelsea chop typically occurs in the third week of May. However, that can be too early for gardens in climates with shorter growing seasons. In a place like northern Minnesota, where the average growing season is 115-125 days, I recommend using the Chelsea chop in the first or second week of June. Significant cutting before June may weaken plants that can’t start their aboveground growth before May.
It’s worth noting that Chelsea chops can be staggered to encourage varied bloom times. To use the Chelsea chop to stagger bloom times, chop only half of each planting section in the first chop. Two weeks later, chop the remaining halves. This will encourage variety in bloom times, extending the flowering season and exploring new bloom combinations.
Black-eyed Susan (Rudbeckia hirta) will produce profuse flowers after a Chelsea chop.
Native plants to Chelsea chop
Many native plants respond well to the Chelsea chop technique. There’s no hard and fast rule, but generally plants with a mounded growth habit (growing vertically and horizontally) respond well to a Chelsea chop. These plants will reinvigorate after cutting and sprout many flowering stems. The reduction in foliage may also help prevent summer flopping and common diseases like powdery mildew.
Here are a few landscape-friendly Minnesota native plant species that respond well to the Chelsea chop technique. I’ve consolidated some plants by genus, using the “spp.” abbreviation to denote multiple species in a genus.
Agastache spp. - Native hyssops, like Anise Hyssop (Agastache foeniculum) and Giant Purple Hyssop (Agastache scrophulariifolia)
Aster, Eurybia, and Symphyotrichum spp. - Native asters, like Aromatic Aster (Symphyotrichum oblongifolium) and New England Aster (Symphyotrichum novae-angliae)
Boltonia asteroides - False Aster
Coreopsis spp. - Native coreopsis, like Lance-leaf Coreopsis (Coreopsis lanceolata) and Prairie Coreopsis (Coreopsis palmata)
Eupatorium perfoliatum - Boneset
Eutrochium spp. - Spotted Joe Pye Weed (Eutrochium maculatum) and Sweet Joe Pye Weed (Eutrochium purpureum)
Euthamia, Oligoneuron, and Solidago spp. - Native goldenrods, like Showy Goldenrod (Solidago speciosa) and Grass-leaved Goldenrod (Euthamia graminifolia)
Helenium autumnale - Sneezeweed
Helianthus spp. - Native sunflowers, like Western Sunflower (Helianthus occidentalis) and Showy Sunflower (Helianthus pauciflorus)
Heliopsis helianthoides - Early sunflower
Monarda spp. - Native bee balms, like Wild Bergamot (Monarda fistulosa) and Spotted Beebalm (Monarda punctata)
Penstemon spp. - Native penstemons, like Foxglove Beardtongue (Penstemon digitalis) and Large Beardtongue (Penstemon grandiflorus)
Physostegia virginiana - Obedient Plant
Pycnanthemum virginianum - Virginia Mountain Mint
Rudbeckia spp. - Native rudbeckias, like Black-eyed Susan (Rudbeckia hirta) and Brown-eyed Susan (Rudbeckia triloba)
Scutelleria spp. - Native skullcaps, like Mad-dog Skullcap (Scutellaria lateriflora) and Marsh Skullcap (Scutellaria galericulata)
Verbena spp. - Native vervains, like Hoary Vervain (Verbena stricta) and Blue Vervain (Verbena hastata)
Vernonia spp. - Native ironweeds, like Prairie Ironweed (Vernonia fasciculata)
Zizia spp. - Native Alexanders, like Golden Alexanders (Zizia aurea) and Heart-leaved Alexanders (Zizia aptera)
Hoary Vervain (Verbena stricta) will bloom through late summer if Chelsea chopped.
Do I need to Chelsea chop native plants?
No! The Chelsea chop is an optional technique for native plants. Some gardeners choose to use the Chelsea chop to create a tidier aesthetic, versus allowing naturalistic growth. Using the Chelsea chop can help native plant landscapes mimic the “neat” garden aesthetic traditionally achieved through non-native, cultivated plants. This is a helpful maintenance technique for native landscaping in formal environments and neighborhoods with restrictive planting rules.
Don’t worry if you choose not to Chelsea chop native landscaping. It’s A-okay to maintain a lower-maintenance native landscape that follows each year’s environmental conditions. Your landscape will have a naturalistic, rural look that provides big ecosystem benefits by restoring native habitat. While plant foliage may be more susceptible to flopping and fungal disease in wet seasons, this will not significantly impact the plants’ perennial health.
If you need help maintaining, restoring, or creating a native landscape, schedule a consultation! We’ll work together to make a plan for your site, and consultation fees are always deducted from the final cost when you sign a design, maintenance, or restoration contract. Together, we can create a beautiful native landscape that functions for you and serves local ecosystems.
