Divide And Transplant Ornamental Grasses
Want to divide Ornamental Grass like a pro? Here’s your step-by-step guide to dividing Ornamental Grasses, when to split warm-season grasses vs cool-season grasses, how to transplant clumps, the best tools, and easy aftercare.
Learn how to rejuvenate tired clumps, fix the donut effect, multiply plants for free, and keep your landscape full of tall ornamental, perennial grasses!
This is an easy, fast project that pays off! You’ll improve vigor, boost bloom, and get more plants for your mixed borders with Perennials, Catmint, Salvia, Russian Sage, Zinnias, and Lantana. Ma Nature loves a good refresh, and your beds will too!
Key benefits of dividing Ornamental Grasses:
- Renews vigor and fuller shape
- Fixes a dead or thin center
- Multiply plants for free
- Improves drought-tolerant performance by balancing roots and shoots
- Eases transplanting to new spots or containers
- Keeps tall grasses upright and less floppy
Tools you’ll need:
- Spade or transplant spade with a sharp, flat edge
- Root saw, old bread knife, pruning saw, or a reciprocating saw for big clumps
- A garden fork or two forks to pry apart heavy masses
- Hori hori or hand pruners for roots and stolons
- Long-handled shovel, tarp, and wheelbarrow
- Hose with a spray nozzle or a bucket of water
- Gloves and eye protection
- Compost, pine bark fines, and arborist mulch
- Optional: mycorrhizae inoculant and starter fertilizer at half strength
Best Time To Divide - Warm-Season vs Cool-Season Grasses
Warm-season grasses
Examples: Miscanthus sinensis (Maiden Grass), Panicum virgatum (Switchgrass), Muhlenbergia capillaris (Pink Muhly), Pennisetum alopecuroides (Fountain Grass).
When to divide: Late spring, once new growth is 3 to 6 inches tall and the soil has warmed. Avoid doing this in the fall if you are in cold climates, so new roots have time to establish.
Cool-season grasses
Examples: Calamagrostis x acutiflora ‘Karl Foerster’, Festuca glauca (Blue Fescue), Helictotrichon sempervirens (Blue Oat Grass).
When to divide: Early spring, just as growth starts, or early fall, at least 6 weeks before a hard freeze. Skip dividing Ornamental Grasses during peak summer heat.
Tips: Aim for an overcast day. Water the clump the day before for easier digging.
Read more on the differences Warm and Cool Season Grasses have and their care.
Step-by-Step Division and Transplant Guide
1. Prep the plant
- For mature clumps, shear last year’s stems to 4 to 6 inches. This reduces stress, improves visibility, and makes lifting safer.
- Water thoroughly the day before.
2. Outline your dig
Use your spade to slice a wide circle 4 to 6 inches outside the living crown. For giant clumps, make it 8 to 10 inches. Stomp the spade straight down to sever outer feeder roots cleanly.
3. Lift the clump
- Slide the spade under the root plate. For heavy clumps, use two garden forks back-to-back to pry up. Tip the clump onto a tarp.
4. Clean the crown
- Spray soil off the roots with a hose to see the natural seams. Trim away dead thatch and the exhausted center debris if it is hollow.
5. Make the splits
- Divide into pie-wedge sections, each with a healthy fan of shoots and plenty of roots.
- Small clumps: pull apart by hand.
- Medium clumps: use a hori hori or hand saw.
- Large, woody crowns: drive the spade through or use a reciprocating saw. Keep divisions 6 to 10 inches across for quicker recovery.
6. Refresh the planting hole
- Loosen the soil 2 shovel blades deep. Work in 1 to 2 inches of compost or pine bark fines for drainage.
- Do not overdo it with nitrogen.
7. Replant at the right depth
- Set crowns at the same soil line as before. Backfill, firm gently, then water to settle.
- Water following our recommended watering tips.
8. Space smart
Proper spacing is key to healthy plants that won't need to compete for nutrients or air flow.
- Warm-season fountain and Maiden Grasses: 30 to 48 inches apart, depending on variety.
- Karl Foerster: 18 to 30 inches for tight hedges.
- Blue Fescue and small tuft-type grasses: 12 to 18 inches.
9. Mulch and stake if needed
Arborist mulch reduces weed competition, holds soil moisture, and insulates plant roots from heat and chill.
- Mulch 2 to 4 inches, keeping it off the crown.
- Stake tall, top-heavy divisions in windy sites for the first season.
10. Aftercare
- Water deeply, then allow the top 1 to 2 inches of soil to dry before watering again. Use the Finger Test to check moisture.
- In hot spells, water 2 times a week (or more) until rooted. In cool, moist weather, weekly is plenty.
- New divisions usually root in 4 to 6 weeks.
Troubleshooting
- Flop or lean: cut taller divisions a bit shorter and stake for a month, or consider moving to a full sun location if your grass is planted in less than 6 hours of direct sun a day.
- Slow rebound: keep evenly moist and avoid heavy fertilizer.
- Rot at crown: lift, remove soggy mulch, and replant into well-drained soil.
Landscaping Uses
Fill your garden with Ornamental Grasses! Now that you’ve got a collection of fresh new grass divisions, it’s time to get creative! Dividing ornamental grasses isn’t just maintenance; it’s free landscaping material waiting for a new home!
Fill bare spots and freshen beds: Use your new clumps to fill thin or tired areas in existing borders. Plant smaller divisions near walkways or at the front of mixed beds where their texture softens hard edges and ties everything together in a mixed perennial border.
Create repetition and rhythm: Plant matching divisions in drifts or repeating patterns throughout the garden. Repetition brings flow and visual harmony, especially with grasses like Big Bluestem or Miscanthus.
Form natural screens or living fences: Tall divisions like Miscanthus or Switchgrass are perfect for instant privacy. Stagger them in a zigzag pattern for a lush, layered screen that still moves with the breeze. An attractive privacy and screening solution that also adds noise reduction.
Edge pathways or patios: Compact types like Blue Fescue or dwarf Fountain Grass make beautiful living borders for walkways and patios. Their tidy habit and fine texture contrast perfectly with pavers or gravel, great for a soft cottage garden look.
Refresh containers: Divide small grasses like Blue Fescue or Japanese Forest Grass and tuck them into pots or window boxes with summer annuals such as Zinnias, Sunpatiens, or Lantana for a destination spot feel.
Anchor new planting areas: Start a new island bed or landscape feature with your divisions as the backbone. Combine tall Ornamental Grasses with Perennials like Catmint, Salvia, or Russian Sage for a layered, low-maintenance focal point.
Stabilize slopes or erosion-prone spots: Use divisions to quickly cover slopes where you need sturdy roots and drought-tolerant plants. Grasses knit soil together beautifully and handle full sun like champs! Try this for erosion control or rain garden areas.
Share with fellow gardeners: Dividing gives you the gift of abundance, so trade or gift your extra clumps! Ornamental grass divisions make perfect pass-along plants that spread joy (and texture) in every direction.
Naturalize meadows or rain gardens: Plant groups of Ornamental Grasses in open, sunny areas. Their graceful sway and wildlife-friendly seeds make them a natural fit for low-water spaces and restoration gardens or edible landscaping designs.
A Graceful Wrap-Up
Divide and conquer is the name of the game. A sharp spade, good timing, and a little muscle will turn one clump into many and keep your borders swaying in style.
Happy Planting!
