How to Propagate Silver Feather Grass by Division

Silver Feather Grass grows into a generous clump that becomes stronger and more densely planted with each passing year. After 3 to 4 years, you may notice the center of the clump beginning to thin or die out, while the edges remain vigorous. Division is the natural solution. Dividing your Silver Feather Grass rejuvenates the plant, gives you new plants to expand your landscape, and takes only a couple of hours of work in early spring.

Why Divide Silver Feather Grass?

Silver Feather Grass is a long-lived perennial that persists in the garden for 10 or more years. However, as the clump matures, the center eventually dies back while the perimeter continues to expand. This is not a sign of failure; it is the plant's natural growth cycle. By dividing every 3 to 4 years, you can revitalize an aging clump and propagate new plants without spending money at a nursery.

Division also allows you to fill in bare spots in your garden or share plants with neighbors. A mature Silver Feather Grass clump, which typically reaches 3 to 4 feet wide (and occasionally up to 5 feet), can often be split into 2, 3, or even 4 vigorous new plants, each capable of reaching full size in 2 to 3 years.

Best Time to Divide

Early spring is the optimal window for dividing Silver Feather Grass. In USDA zones 5 to 9, this means late February through March, or as soon as the soil becomes workable and before new growth emerges from the base of the clump. Do not divide in fall or winter; the new divisions will not have time to establish roots before cold weather arrives, and winter frost can heave them out of the ground.

The reason spring works best is straightforward: the plant is about to enter its most vigorous growth period. Fresh roots will develop quickly in warming soil, and each division will have a full growing season to establish itself before autumn dormancy.

Materials You'll Need

• A sharp spade or garden spade (a round-nose shovel is less effective here)
• A mattock, pickaxe, or old kitchen knife (for prying and cutting through tough root tissue)
• Pruning shears or a hand saw (for cutting through dense rhizomes)
• Work gloves (leather, to protect from sharp leaf edges)
• A bucket or tarp (to contain the clump and soil as you work)
• Compost or well-draining soil amendment (optional, for planting divisions)
• Water source and watering can or hose

Step-by-Step Division Process

Step 1: Cut Back the Foliage

Before you dig, cut the entire Silver Feather Grass clump back hard to about 4 to 6 inches above ground level. This is the same height you would use for your annual late-winter or early-spring pruning. Cutting back first makes it much easier to see what you are doing, reduces the weight and bulk you have to handle, and prevents the long foliage from getting in your way as you work with the roots. Use sharp pruning shears or a reciprocating saw for speed on large clumps.

Step 2: Dig Up the Entire Clump

Use your spade to cut a circle around the clump, about 12 inches away from the visible foliage base. Go deep: Silver Feather Grass roots extend down at least 12 to 18 inches. Once you have cut all the way around, work the spade under the clump at an angle to loosen and lift it free of the surrounding soil. You may need to lever and twist to break the root ball free. Have someone help you lift if the clump weighs more than 40 or 50 pounds (a mature clump often does).

Step 3: Shake or Wash Off Excess Soil

Place the clump on a tarp or in a wheelbarrow and shake off loose soil. If the root ball is very compacted or muddy, rinse it with water from a hose to expose the rhizomes and root structure. You need to see the natural divisions and growth points before you cut. Do not fully clean away all soil; some clinging to the roots is fine and helps protect them.

Step 4: Identify the Natural Division Points

Silver Feather Grass grows from rhizomes (horizontal underground stems) that branch and create distinct shoot clusters. Look for the places where the rhizomes naturally separate or where you can identify individual "fans" of shoots. The center of the clump, if it has died back, will be obvious. The living portions around the perimeter are what you want to propagate. Avoid pieces that contain large areas of dead tissue in the middle.

Step 5: Split the Clump

Use a mattock, pickaxe, or heavy-duty knife to split the clump along the natural divisions. Start from one side and drive the tool into the clump with firm, deliberate blows. The goal is to break the root mass into manageable pieces, each containing 3 to 5 healthy shoots and plenty of attached rhizomes and roots. You can make 2 to 4 divisions from one mature clump, depending on its size.

Discard any portions of the clump that consist mainly of dead tissue or very thin, weak shoots. These will not establish well and are not worth the space or effort.

Step 6: Trim Damaged Roots

Once you have your divisions, use pruning shears or a sharp knife to trim back any roots that were torn or badly damaged during the splitting process. Make clean cuts at healthy-looking white or light tan root tissue. Remove roots that are mushy, dark, or obviously dead. Healthy roots are firm and pale; diseased or dying roots are soft and dark brown or black.

Aftercare and Establishment

Plant each division in a hole that is at least as wide as the root mass and deep enough so that the rhizomes are about 1 to 2 inches below the soil surface. Space new plants 3 to 4 feet apart if you are creating a mass planting or screen. Backfill with amended soil (topsoil mixed with compost is ideal) and water thoroughly to settle the soil around the roots and remove air pockets.

Water newly divided plants consistently during their first growing season, aiming for about 1 inch of water per week if rainfall does not provide it. Once the plants are established (typically by the second growing season), Silver Feather Grass becomes quite drought tolerant and needs water only during extended dry spells.

Do not fertilize heavily. Silver Feather Grass is a light feeder, and excess nitrogen can cause weak, floppy stems. If you choose to fertilize at all, apply a balanced spring fertilizer at half strength.

Tips for Success

Sharp tools make the job faster and cleaner. Dull spades and knives tear roots and make splitting harder. Sharpen your spade and have your knife honed before you start.

Divide on a cool, overcast day if possible. Bright sun and heat can stress newly divided plants. If you must divide on a sunny day, keep the exposed roots shaded and moist until they are planted.

Do not let divisions sit around for hours or days after splitting. Plant them as soon as practical after digging. If you must delay, keep the roots moist by covering them with burlap or placing them in a shaded location with soil or compost heaped around them.

Handle the divisions gently when carrying them. Avoid dropping or crushing the shoots or root mass.

Common Mistakes to Avoid

Dividing at the wrong time is the most frequent error. Fall or winter division rarely succeeds because the new plants do not have time to develop roots before cold weather. Always divide in early spring.

Creating divisions that are too small will slow their recovery. Aim for divisions with at least 3 to 5 healthy shoots each. Tiny divisions with just one or two shoots take much longer to reach mature size and are more vulnerable to stress.

Planting divisions too shallow or too deep causes problems. The rhizomes should sit 1 to 2 inches below the surface. If they are planted deeper, they may rot; if too shallow, they may dry out or frost heave.

Overwatering newly planted divisions is tempting but counterproductive. Keep the soil consistently moist, not waterlogged. Waterlogged soil promotes root rot, especially in clay soils.

Expected Results

Each division should send up new shoots within 2 to 4 weeks of planting in spring. Growth will accelerate as soil warms. The first year, do not expect the division to reach its full mature height of 6 to 8 feet (which includes flower plumes). Instead, divisions typically gain roughly 1 to 3 feet of height during their first season as the root system becomes established.

By the second and third growing seasons, your divisions will reach close to full mature size and will produce abundant silvery-pink plumes that mature to silvery-white in late summer and fall. The long-term lifespan of a properly maintained division is the same as the parent plant: 10 or more years in the garden.

Quick Reference Checklist

Task	Timing / Details
Choose Division Season	Early spring (late Feb.–Mar.), zones 5–9
Cut Back Foliage	4–6 inches above ground before digging
Dig Clump Depth	12–18 inches deep to capture all rhizomes
Wash/Expose Roots	Rinse to see natural division points clearly
Division Size	3–5 healthy shoots per division; discard dead center
Trim Damaged Roots	Remove torn, dark, or mushy root tissue
Planting Depth	Rhizomes 1–2 inches below soil surface
Spacing	3–4 feet apart for new divisions
Initial Watering	Consistent moisture; 1 inch/week first season
First-Year Height Gain	Roughly 1–3 feet (not full 6–8 ft)
Full Size Achieved	By year 2–3 after division
Re-divide Mature Clump	Every 3–4 years to rejuvenate

For more on caring for your Silver Feather Grass after division, see our complete growing guide.