Ornamental grasses add texture, movement, and visual interest to any landscape. As the seasons change, knowing when and how to cut back ornamental grasses is key to keeping them looking their best. Here is a comprehensive guide on cutting back ornamental grasses.

When to Cut Back Ornamental Grasses

Timing is crucial when cutting back ornamental grasses. Here are the optimal times:

Spring

Cut back warm-season grasses in early spring before new growth emerges. This includes grasses like miscanthus, pennisetum, and panicum.
Leave any dead foliage in place over the winter for insulation. Cut it back to 4-6 inches from the ground as soon as you see new green growth emerging.

Summer

Leave cool-season grasses like festuca, deschampsia, and calamagrostis untouched in summer. Cutting back too early can damage new growth.
If desired for aesthetics, trim off summer Flower stems after blooming finishes. This encourages lush green regrowth.

Fall

Cut back cool-season grasses after several hard frosts when foliage starts to look unsightly. Leave 3-4 inches of stubble.
For miscanthus and other large grasses, wait until late fall after foliage browns completely.

Avoid Cutting

Never cut grasses back in winter or early spring growth will be compromised.
Don’t cut grasses shorter than 3-4 inches or you risk damaging the crown.

How to Cut Back Ornamental Grasses

Proper technique is important when cutting back ornamental grasses to avoid harming the plant. Here are some key tips:

Use Sharp Blades

Invest in good quality, sharp garden shears, grass shears, or hedge trimmers.
Dull blades will tear and shred grasses rather than making clean cuts.

Cut at an Angle

Cut leaf blades and stems at a 45 degree angle rather than straight across.
Angled cuts better facilitate water runoff.

Work Outward In

Start by trimming outer grass blades first, working inward toward the center.
This helps prevent the trimmer from getting gummed up.

Remove No More Than 1/3

Never remove more than one third of the total foliage height when cutting back.
Taking too much in one pass can stress the plant. Make successive passes for heavy cutting.

Leave Some Foliage

Always leave at least 2-3 inches of leaf growth after cutting ornamental grasses.
Never cut down to the very base or you risk damaging the crown and stunting regrowth.

Rake Away Trimmings

Rake or blow away trimmings promptly after cutting for a neat appearance.
Leftover debris can harbor pests and diseases.

Fertilize Afterwards

Applying a balanced fertilizer after cutting back gives grasses a boost of nutrients.
This fuels regrowth and helps plants bounce back quickly.

When and How to Cut Back Specific Ornamental Grasses

The timing and technique for cutting back ornamental grasses depends on the variety. Here are tips for some of the most popular types:

Maiden Grass (Miscanthus)

Cut maiden grass back to 4-6 inches in late winter before new shoots appear.
Remove old stems and leaves carefully with grass shears, starting from the outside and working inward.

Pampas Grass (Cortaderia)

Trim pampas grass foliage to 6-8 inches in early spring as new growth resumes.
Use sharp pruners to cut away old leaf blades close to the base without damaging new shoots.

Fountain Grass (Pennisetum)

For fountain grass, cut back foliage to around 4 inches in early spring.
Use hedge trimmers to remove old growth down to just above the crown.

Moor Grass (Molinia)

Cut moor grass back hard in late winter, leaving just 2-3 inches of stubble.
Rake thoroughly to remove the substantial debris this variety generates.

Tufted Hair Grass (Deschampsia)

Wait until early spring to cut back tufted hair grass as growth resumes.
Remove tattered, wintery foliage, leaving fresh green tufts 4-6 inches tall.

Caring for Ornamental Grasses After Cutting Back

Proper aftercare once grasses are cut back is crucial. Here are some tips:

Inspect for any damage or signs of disease and prune accordingly.
Water well after cutting to reduce transplant shock.
Apply a balanced fertilizer to nourish and stimulate new growth.
Top dress with fresh mulch to conserve moisture and suppress weeds.
Stake or trim back any grasses that become unruly or collapse after cutting.
Monitor for pest problems and treat promptly if any are found.

Conclusion

Learning the optimal time and techniques for cutting back ornamental grasses is essential maintenance. With the right approach, you can keep your ornamental grasses looking healthy and vigorous year after year. Always remember to use sharp blades, cut at an angle, and avoid overcutting. Proper follow-up care after cutting back also helps grasses recover and thrive.

FAQs About Cutting Back Ornamental Grasses

How short can you cut ornamental grasses?

Aim to cut ornamental grasses down to 3-4 inches above soil level at minimum. Cutting any shorter risks damaging the crown and stunting regrowth the following season.

Should you cut ornamental grasses in the fall or spring?

Cut back warm-season grasses in early spring as new growth resumes. For cool-season grasses, wait to cut back until late fall after several hard frosts.

What is the best tool for cutting ornamental grasses?

Quality shears, trimmers, or pruners with sharp, clean blades make cutting back grasses easy. Dull tools will shred and tear instead of making clean cuts.

Do you have to cut back ornamental grasses every year?

Yes, ornamental grasses should be cut back yearly to remove dead growth and maintain an attractive form. Proper annual cutting keeps grasses full and vigorous.

Should you fertilize ornamental grasses after cutting back?

Applying a balanced granular fertilizer after cutting back is recommended. This provides nutrients that nourish new growth and aids recovery.

What do you do with ornamental grass clippings?

Always rake or blow away trimmings promptly after cutting ornamental grasses. Debris left on the crown can lead to pest and disease problems.

How do you cut back large ornamental grasses?

For overgrown grasses, cut in multiple passes starting from the outer edges, removing no more than one third of growth at one time. This reduces shock to the plant.

Can you leave ornamental grass stands for the winter?

Leave ornamental grass foliage in place over winter for insulation, only cutting back once new growth resumes in spring. Removing it too early risks cold damage.

How do you revive ornamental grasses that flop over?

Cut back any collapsed foliage, then fertilize and keep watered. Staking may be needed temporarily to support regrowth that is top heavy or floppy.

What is the best way to dispose of ornamental grass clippings?

Compost grasses trimmings, use for mulch, or dispose with other yard waste. Do not leave large piles that can mat and inhibit new growth.

How and When to Cut Back Ornamental Grasses