Fall is the perfect time for Ohio gardeners to divide perennials before winter sets in. Dividing overcrowded plants helps them thrive by giving roots more space to grow and absorb nutrients.
Your garden will reward you next spring with healthier plants and more abundant blooms if you take time now to split these perennials.
1. Bearded Iris
Bearded irises develop thick, crowded rhizomes after a few years, resulting in fewer flowers. Carefully dig up the entire clump with a garden fork, and cut the rhizomes into sections with a sharp knife.
Each division should have healthy roots and at least one fan of leaves. Replant with the rhizome sitting at soil level – never bury them deeply! Ohio’s clay soils drain better when these beauties sit high.
2. Black-Eyed Susans
These cheerful yellow blooms spread like wildfire in Ohio gardens! When the center of your Black-Eyed Susan patch starts looking bare or blooming less, it’s crying out for division.
Dig around the perimeter, extracting chunks of the plant with roots intact. Younger, outer portions produce the most flowers, so focus on those. Toss the woody center sections and replant the vigorous edges for a magnificent golden display next summer.
3. Hostas
Magnificent in Ohio’s shady spots, hostas eventually form massive clumps that benefit from division every 4-5 years. Wait until after the first light frost when leaves begin yellowing but before the ground freezes solid.
Lift the entire plant and use two garden forks back-to-back to pry the root ball apart. For larger varieties, a sharp spade can slice through the crown. Each division needs several healthy leaves and roots to thrive in its new location.
4. Daylilies
Practically bulletproof in Ohio landscapes, daylilies still need occasional rejuvenation when flowering decreases. Autumn division gives them time to establish before winter dormancy.
After digging up the clump, shake off excess soil and pull apart the fans with your hands. No special tools needed! For stubborn clumps, use a garden fork to separate them.
Each division should have at least 3-5 fans of leaves with healthy roots attached for best results next summer.
5. Bee Balm (Monarda)
Bee balm’s spreading habit makes it perfect for division every 2-3 years. When the center starts dying out, leaving a donut-shaped plant, it’s definitely time to rejuvenate.
Dig up the entire clump and separate the healthy outer portions with strong roots. Discard the woody middle section that’s past its prime.
Ohio’s native pollinators will thank you next summer when your refreshed bee balm puts on a spectacular show of fragrant blooms!
6. Coneflowers (Echinacea)
Native to the Midwest, coneflowers thrive in Ohio’s climate but can become overcrowded after several years. Fall division keeps these prairie plants vigorous and blooming abundantly.
Use a spade to slice through the outer edges of established clumps, leaving the main plant intact if desired. Each division needs a portion of crown with roots and several growth points.
Leave the seedheads on undivided plants – goldfinches love them during winter!
7. Peonies
Unlike most perennials, peonies rarely need division – they can thrive for decades! But when you want more plants or they’ve stopped flowering well, September to October is perfect timing in Ohio.
Carefully dig around and under the entire root ball. Wash off soil to see the pink “eyes” (buds) on the roots. Using a sharp knife, cut sections ensuring each has 3-5 eyes and good roots.
Plant divisions with eyes just 1-2 inches below soil surface for best flowering.
8. Ornamental Grasses
Miscanthus, feather reed, and other ornamental grasses develop dead centers as they age in Ohio gardens. Early fall division keeps them looking their best.
Cut back foliage to about 6 inches tall first – much easier than wrestling with full-sized plants! Use a sharp spade or saw to cut through the tough root mass.
Replant the vigorous outer sections and compost the woody center. These divisions establish quickly before winter in Ohio’s typically moist autumn conditions.
9. Astilbe
Shade-loving astilbes create breathtaking plumes in Ohio gardens but need division every 3-4 years to maintain vigor. Their shallow root systems make them easy to lift in early fall.
Gently tease apart the clumps with your fingers or use a small trowel for tougher sections. Each division should have several growth buds and a good portion of roots.
Replant immediately and water thoroughly – astilbes hate drying out! A layer of mulch helps them establish before Ohio’s winter arrives.
10. Shasta Daisies
Those cheerful white blooms start to diminish when Shasta daisies become overcrowded. After about 3 years in Ohio gardens, the centers often die out, signaling division time.
Lift the entire clump and pull apart the outer growth into smaller sections, each with roots and several shoots. The old center can be discarded.
Fall division gives these summer bloomers time to settle in before winter, resulting in stronger plants and more flowers next year.
11. Yarrow (Achillea)
Drought-tolerant yarrow thrives in Ohio’s variable conditions but tends to spread aggressively. Division every 2-3 years keeps it contained and rejuvenated.
Simply dig up portions from the edges of established plants – no need to remove the entire clump. The fibrous root system separates easily by hand or with a garden fork.
Yarrow establishes quickly when divided in fall, and Ohio’s native butterflies will appreciate your efforts when fresh blooms appear next summer!
12. Garden Phlox
Tall garden phlox creates spectacular summer color but becomes susceptible to powdery mildew when overcrowded. Division every 3-4 years improves air circulation and plant health.
Dig around the clump and lift the entire plant. The root ball can be split with a sharp spade or pulled apart by hand into smaller sections.
Each division should have several stems with roots attached. Replanting in fall gives them time to establish before Ohio’s hot, humid summers return.
13. Coral Bells (Heuchera)
Heucheras develop woody stems that rise above the soil surface after several years in Ohio gardens. This “legginess” means it’s time for division to rejuvenate them.
Lift the entire plant and cut through the crown with a sharp knife, ensuring each section has both roots and foliage. Replant divisions deeper than they were originally growing, covering those exposed woody stems.
Fall division allows these colorful foliage plants to establish strong roots before winter.
14. Siberian Iris
Unlike their bearded cousins, Siberian irises form dense, fibrous root systems that can become woody and unproductive in the center. When blooming decreases, typically every 4-5 years, division rejuvenates them.
Dig the entire clump and use a sharp spade or saw to cut through the tough roots. Ohio gardeners often need to employ serious muscle for this job!
Smaller divisions establish faster than large chunks. Trim the foliage to about 6 inches to reduce moisture loss while roots reestablish.