Watch the step-by-step video here.
Step 1 — Measure and spread or mix
For containers, add about half a cup of wool pellets to every four cups of potting soil. You can mix them right into the soil before planting, or sprinkle them on top of an already-potted plant.
For raised beds and in-ground gardens, spread a thin layer of pellets across the soil surface or work them into the top few centimetres. There's no need to bury them deep. They'll expand and settle once watered.
If you're top-dressing an existing bed, just scatter the pellets around the base of your plants. Over time the pellets will expand and form a dense crust on the soil's surface.
Step 2 — Water to activate
Once the pellets are in place, give them a good soak. Water is what triggers the expansion. Dry pellets are compact, but they swell and soften as they absorb moisture.
This is the step that makes the difference. The expanded wool acts like a sponge in your soil, holding water near roots and releasing it as the surrounding soil dries out. You should notice the pellets puff up within a few minutes of watering.
Step 3 — Let the pellets work through the season
After watering in, the pellets do their job quietly. They hold moisture between waterings, which may mean you water less often, though how much depends on your climate, container size, sun exposure, and soil mix.
Over weeks and months, soil organisms begin to break the wool down. That slow decomposition is what releases small amounts of nitrogen and other nutrients back into the soil. It's not a replacement for a balanced fertilizer program, but it's a helpful contribution, especially in containers where nutrients wash out quickly.
You don't need to remove the pellets at the end of the season. Whatever hasn't fully broken down can stay in the soil or get turned into next year's bed.
What to expect
In the first week or two, you'll see the pellets expand and settle into the soil surface. Over the following months, they'll gradually felt and soften as they decompose.
Moisture retention is the most noticeable benefit early on. Many gardeners report longer intervals between waterings, particularly in containers and raised beds that tend to dry out fast. Results vary with application rate, weather, and soil type.
Rhubarb in clay soil with wool pellets mixed in around the base, June 2025.
From my garden, June 2025
I've been incorporating wool pellet mulch into the clay soil around my spring transplanted rhubarb, and I'm loving the results. I'm seeing healthy plant growth, better moisture retention, and weeds that are easier to remove, roots and all.
— Lindsey, WoolGrown
Wool felt products (sheets and rolls) work differently from pellets — they sit on the soil surface as a weed-suppressing mulch. If you're curious about those, the WoolGrown shop has details on sizing and application.
FAQ
How do I use wool pellets in potting soil?
Mix half a cup of wool pellets into every four cups of potting soil. Blend them evenly through the root zone, then water well after planting.
Can I add wool pellets to plants that are already potted?
Yes. Sprinkle them on the soil surface, keep them away from stems, gently work them into the top of the soil, and water them in.
Will I water less with wool pellets?
It may help. The wool soaks up water and releases it as the soil dries, so many gardeners go longer between waterings. How much depends on your climate, pot size, sun and soil mix.
Do I need to remove the pellets at the end of the season?
No. Whatever hasn't broken down can stay in the soil or get turned into next year's bed.
Ready to plan your next bed? The WoolGrown Usage Guide has the starting rates for every kind of planting.
If you want a starter bag sized for containers and small beds, WoolGrown's wool pellets are made in Ontario from Canadian wool. Start with a small mix ratio, water well, and adjust next season.
Written by Lindsey Weber, founder of WoolGrown
WoolGrown turns Ontario sheep wool into garden products, including wool pellets, felt and mulch.