Here is another great article from our member, Anne Patterson. Thank you, Anne, for going the extra mile to get this article to us.
Feature photo credit: Winsom Farm
Studies of the effect of treating soil with wool pellets compared with commercial fertilizers have found that tomatoes fertilized with wool were up to 69% larger than unfertilized plants. (Bradshaw and Hagen, 2022)
When it comes to getting ready for winter weather, what is good for the gardener is also good for the garden. An attempt to help small sheep farmers to boost their incomes by using scrap wool as a soil amendment has given gardeners an organic soil additive that slowly releases nitrogen and other nutrients, greatly increases soil water-holding capacity. Wool is like a sponge, and can hold up to 30 times its weight in water. It can also be used as long-lasting mulch on the soil surface.
Sheep farmers in Europe, the US, and Canada face the same problems: the demand for wool is dropping and the market for meat is limited. Most sheep breeds have to be sheared, resulting in a significant amount of waste wool that has to be stored or disposed of in landfills at the expense of the farmer.
How wool pellets are made
Wool pellets were first developed by Utah sheep farmer Albert Wilde in 2016.
They’re made using low-quality wool that is shredded and compacted into pellets of roughly six millimetres in diameter, which can be sprinkled on the surface of pots and gardens, or worked into the soil. For farmers, the cost savings offered by this method of pelletizing wool is that the raw wool does not have to be washed or prepped prior to processing. The raw fleece is first put through a shredder, and then a pelletizer using intense heat. The heat kills any pathogens or pests.
Photo credit: South Dakota State University
How to use, where to buy pellets
Wool pellets can be mixed into the first few inches of soil in pots, raised beds or in-ground beds. They decompose over a period of 3 to 6 month. Here’s the suggested ratio of pellets to soil:
- When mixing into soil: Blend ½ cup of pellets with 4 litres of soil before planting.
- For garden beds: Apply 1 kg of pellets per 2 square metres and work them into the top layer of soil.
- As a mulch: Spread enough pellets to completely cover the surface of the soil around your plants.
Pellets are very light and can be mail ordered from producers around BC. Winsom Farms in Chilliwack sells 1 kg bags for $25., 2 kg for $46. Lee Valley in Kelowna sells 350g for $12.50 online or in-store.
Wool mulch mats/raw fleece
Another promising application for wool in gardens is as a mulch. There are now felt-like wool mulch mats on the market. Less expensive is the application of wool fleece acquired from local farmers and applied directly on soil.
Preliminary studies suggest that the effectiveness of wool mulch in lowering water usage depends on the type of soil. In fast-draining, sandy soil it does not reduce the need for irrigation noticeably. In medium-draining soil it is effective.
Applying wool on top of the soil in the form of mulch mats or raw fleece makes it difficult for weeds to penetrate. Anecdotally, people have also seen a reduction in the number of slugs in their garden when using wool as mulch. Wool mulch may help to regulate soil temperature. It can take at least two years for wool to fully decompose, so it can offer benefits for multiple growing seasons (Broda, et al., 2023).
Wool mulch mats are being produced locally by Amanda Simmons, of Oliver-based Quail & Vine farm.
(You can find them on FaceBook and Instagram.)
