Mulch is any material that can be placed onto your existing soil to reduce wind erosion, increased water retention, and protection for your plants. On top of these benefits, mulching creates a ‘warm blanket’ over your soil, increasing microbial and fungal growth whilst providing a slow-release fertilizer. Any organic material can be used for mulch–leaves, straw and more. However, in our experience local arborist wood chips from untouched forests are typically the best form of mulching that can be acquired.
Knowing all of the benefits of organic mulching, there are a few special steps you must take in establishing fresh-mulched gardens. Many people have mulched their existing gardens only to have difficulty growing new plants. It is important to do it correctly the first time.
The first year you lay your wood chips down you will not be able to plant directly into it; this is called the ‘establishing year’. You can plant underneath the mulch layer directly into the soil if you must. However, in our experience, it is best to lay the mulch down for a season to ‘activate’ it and allow for some additional composting.
When mulching a new garden or over grass, be sure to lay down newspaper to cover the existing grass or soil. This allows the mulch to settle onto the paper with no weeds or the like growing through the mulch.
After the newspaper is laid, begin spreading fresh wood chips on your desired area. Allow for eight inches of wood chips. Typically we want to plant with four inches of wood chips but we have found that after raining and settling, the six inch mark is a better starting point.
After the mulch is laid down, we prefer to top dress with a lightly amended compost. We use our homemade earth worm castings combined with kelp, crustacean meal, alfalfa meal and glacial rock dust. We spread a very light ‘dusting’ layer of this over the wood chips and allow to settle for the year.
After the first season it is time to plant. Gently remove all of the mulch around the plant site. Do not dig anything. On top of the soil/composted newspaper, put a large handful of earth worm castings. Dust the EWC or root zone of the plant or the seed itself with mychorrizal fungus. Plant directly into the earth worm castings, allow a small half inch layer of wood chips to rest on top. Keep moist for a week. Once the plant is established, slowly add a 2-3 inch layer of mulch around the plant. Do not but the mulch directly against the stem. On areas not near the plant, you can build the mulch to 4-6 inches for better moisture retention.
If you plant directly into the mulch your plants will not do well. The bacteria and fungal dominance of the soil will ‘latch’ onto the wood chips and will utilize their energies to break that matter down before working in the soil and with the plant itself. If you do plant in the mulch we typically see wilting and/or dying as well as major nutrient deficiencies–most notably nitrogen.
At the end of the growing season and well into fall, we dig small holes directly in the mulch and ‘plant’ whole dead fish. We typically use mackerel for this, but any fish will do. The fish will breakdown in the soil during the winter season and will be almost completely gone come Spring. In the Spring, we dust the mulch with kelp and alfalfa meal.
This post was written by sperling