In addition to being a passionate handspinner, Dr. Sabine Schröder-Gravendyck is a naturalist and educator in the north of Germany. For years, she has been finding ways to put wool to work in natural spaces. She has so many great tips for using wool in gardening and landscaping that we’ve created a two-part series. This first article is about using unspun wool; a companion piece will follow soon with ideas for spinning specifically for outdoor uses. Enjoy! —Spin Off Editors
Many of our needs can be met with wool: warmth from cozy sweaters, protection from durable winter coats, creative fuel for self-expression, and more. Spinners working with fleeces also accumulate wool that seems less useful. What should we do with the parts of our fleeces that are very dirty, are cotted (felted), or have fibers of lower quality? I want to share with you the many ways you can use “waste” wool to create habitats, feed your garden, and put this beautiful resource to work.
Rhubarb with wool mulch held in place by thin sticks.
Tips for Using Unspun, Unwashed Wool in the Garden
1. Wool as fertilizer
Wool is a protein fiber containing high amounts of nitrogen. As wool decomposes and returns to the soil, the nitrogen slowly and steadily becomes available for plants. As a 100% organic product, wool is 100% biodegradable.
Sulfur (S), phosphorus (P), and potassium (K) are also parts of the highly complex fiber structure. These nutrients are released as wool degrades, which makes wool a great fertilizer. It can be mixed into soil in raised beds or other garden spaces. Studies have found that waste wool is an excellent nutrient source for high-value crops in both greenhouse and field-production systems. Additionally, research shows that wool used as a soil amendment improves the soil’s biological and chemical properties.1
While this practice has gotten more attention lately, it isn’t new. For example, in Shoddy: From Devil’s Dust to the Renaissance of Rags, author Hanna Rose Shell describes shoddy—recycled wool mechanically torn into lint—being traditionally used to nourish various crops in England, from hop fields in Kent to rhubarb in Yorkshire. In addition, shoddy refers to “scraps and leftovers from the wool scouring industry.” The author says that these were the two main components of the shoddy heap (in the landscape).2
2. Wool as mulch
Placing a layer of wool on the soil surface as a mulch keeps moisture in the soil by reducing evaporation. It reduces erosion and runoff by protecting the soil surface, allowing water to more easily soak into the soil. A moderate woolly layer suppresses weeds and hosts little creatures working away in the soil. Wool as mulch also releases nutrients and lasts longer than many other materials used for mulching.
Wool mulch needs to be held in place by something: thin sticks stuck diagonally into the ground through the wool layer, twigs or stones as a weight—whatever you have at hand to prevent the wool from being blown away by the wind.
Two of the “three sisters”: corn and squash.
3. Wool to facilitate germination
A thin layer of wool keeps humidity in the soil to provide the perfect germination environment and to prevent seeds from being eaten by birds. After germination, the little plants need air and light, so the wool cover can be gently rearranged into mulch around the plants.
4. Wool for water management in pots
Wool is known for its ability to hold water. When blended with potting soil or placed in the base of a pot, wool stores and releases water.
Wool added to the base of a pot or in thin layers with potting soil can help retain and release water.
5. Wool for spot protection
One spring, a friend planted a young Cornelian cherry tree in the well-drained, sandy soils of our local area in northern Germany. In summer, she called me because the little tree was drying up in front of her eyes. It was hot and dry, and no rain was in sight.
I took some wool to my friend and made a thick wool cover around the tree—thicker than typical mulch. She then thoroughly watered the tree in the morning and evening. The wool stopped the water from evaporating and improved the soil quality, allowing the tree to recover and grow new leaves. A woolen cover, thicker than a moderate mulching, can help protect your perennial plants from low temperatures as the seasons change as well.
A newly planted dogwood tree was losing leaves despite being watered. A dense layer of brown wool at the base of the tree saved it.
6. Wool to enrich your compost
Retaining humidity, adding nutrients, and hosting little humus-producing creatures makes wool the perfect supplement to your compost. Place a layer of one or two inches as a cover on your compost to maintain a good working humidity for the composting process. Add a layer of dry leaves and grass clippings, veggie peels, tea leaves, or whatever you have on hand. Then add a thin layer of wool and so on.
7. Wool protection against snails, slugs, and more
A layer of fiber can be useful as a kind of repellent, because it makes it less comfortable for bugs to crawl across. Some gardeners are very satisfied with this method while others are not, it can also be a partial success. Give it a try to see how it works in your garden.
A thick layer of wool covering a compost pile.
Ready to start destashing fleece to your garden beds? Here are some things to keep in mind.
- Wool does an excellent job holding moisture, so take care when placing it around plants and trees. Leave space around stems and trunks so moisture is not held directly against the plant or tree. Just a bit of breathing space helps.
- Wool insulates! It can keep soil temperatures cool in the early spring, so you might need to remove last year’s wooly mulch if you want damp spring garden beds to be ready for planting.
Notes
Valtcho D. Zheljazkov, “Assessment of Wool Waste and Hair Waste as Soil Amendment and Nutrient Source,” Journal of Environmental Quality, 34: 2310–2317, November 7, 2005.
Hanna Rose Shell, Shoddy: From Devil’s Dust to the Renaissance of Rags (Chicago: The University of Chicago Press, 2020), 159.
A. Sabine Schröder-Gravendyck, DVM, makes her home on Germany’s North Sea coast, where she works as a naturalist and educator in sustainability and ecology. She is always looking for new ways to help people merge their personal spaces with nature. Learn more at florafauna.pro.