Pros and Cons of Raw Wool as Garden Mulch

One mulch that has had many homestead gardeners excited in recent years is wool. After all, it is completely natural, and for those who raise sheep it is also readily available.

But before jumping on the wool-mulching bandwagon, it is best to take a look at the pros and cons of mulching with wool. What works well in one situation may not be desirable in another.

With this in mind, let’s dive in.

Pros

  • A use for low-value fleece. Part of shearing a sheep includes what is known as skirting—snipping off dirty or low-quality fleece, particularly from the belly and hindquarters. This fleece has very little value, but it is perfectly acceptable for mulching.
  • Long-lasting weed control. The density of raw wool makes it an effective weed barrier. It usually continues to serve this purpose for two years.
  • Steady moisture. Wool is exceptionally good at stabilizing the soil moisture supply. It absorbs rainfall like a sponge, protecting plants from drowning, then slowly releases this moisture over time. As an added bonus, this protection from pounding rains will help improve soil structure over time.
  • Slug control. For those who battle slugs in the garden, wool can be far superior to straw as a mulch because of its microscopic barbs, which serve as an effective deterrent.
  • Deer discouragement. Gardeners report that deer do not like the smell of wool.
  • Nitrogen boost. Many natural garden mulches are high in carbon, which can pull nitrogen out of the soil as they decompose. Wool, on the other hand, slowly releases nitrogen into the soil as it breaks down. Anecdotal evidence suggests that plants flourish when nourished by this slow-release nitrogen.
  • Soil temperature moderation. A wool mulch benefits plants much like a wool sweater does you when it comes to insulation. Wool keeps the soil cool in the summer and warm in the fall, extending your growing season.
  • Attractive appearance. Gardeners frequently comment that they find wool mulches aesthetically appealing, unlike newspaper and cardboard.

Cons

  • Availability. To mulch with raw wool, you must either keep sheep or be acquainted with someone who does.
  • Bulk. Wool is bulky (again, think of your favorite sweater). This means that it can be a pain to transport and store.
  • Seeding difficulties. Because wool forms a dense mat and does not decompose quickly, it can make direct seeding challenging. This is primarily a problem when succession planting fast-growing vegetables. It should not pose as much of a difficulty for seedlings that are transplanted into the garden, especially if they will remain in place for most of the growing season.
  • Squash incompatibility. Some gardeners report that squash fruits rot when in direct contact with the fleece.
  • Slow composting. If you decide to remove your fleece mulch, it will compost, but very slowly (often taking up to two years). Of course, if you plan to reuse your mulch from year to year, this will not present a problem.

Conclusion

As you can see, there are very few disadvantages to mulching with raw wool, provided that you have access to it and that you do not mind handling its bulk.

To avoid the remaining difficulties of mulching with wool, consider the following tips:

  • Use wool with perennials and transplants, not in areas where you will directly sow seeds.
  • Top the wool with a layer of straw to protect squash fruits.
  • Remove the wool as needed to rotate your garden crops, but put the used wool on a different plant instead of in the compost pile.

With these simple strategies, you should have no difficulty in reaping the benefits wool brings to soil and plant health.

Helpful Resources

Adding Value to Wool
More information on making the most of your fleece harvest.

Improving Your Garden Soil

Improving Your Garden Soil
Includes tips for working mulches into your broader soil improvement strategy for healthy plants and nutrient-rich food. Free sample pages are available.