Cover that Soil! Mulch 101
What do permaculturists cringe at most?
Is it people throwing out their cardboard instead of sheet mulching it?
Is it seeing water tankers filling up homes' water while it's raining and could easily be harvested?
Is it watching veggie scraps get binned and destined for landfill instead of compost?
While we certainly don't like to see those thing either, the thing that really makes us cringe is...
When we leave our soil bare (exempt times would be after freshly seeding a garden bed), we are telling all of our soil food web friends, like worms, that we don't care if they live or get snatched up by birds. We are telling the soil that we don't mind if its nutrients get leeched out by sun rays. We are telling our plants that it's just fine if they dry out and suffer for moisture, because the sun has taken that too.
One of the first things we learn in permaculture is to observe nature & mimic patterns of nature in our systems. Welp, nature is just about always dropping leaves & covering up her soils with organic matter. Mulching our soil (aka covering exposed soil with dried carbon material like fallen leaves or straw) is the replication of this functional pattern of nature.
There are soooo many benefits to this simple, yet impactful, act. Let's review them.
Mulch provides protection for the soil & her billions of organisms from harsh UV rays and wind erosion. Protection from evaporation means a more water efficient garden and reduced watering demands. It also helps regulate soil temperatures (warmer in temperate climates and cooler in tropicals ones) which benefits the microbes, root growth & plant nutrient uptake.
Because the soil is specifically covered around our crops, we are reducing the possibility of weed seeds photosynthesising. Thus mulch is a natural weed-repellent.
Mulch is made of organic materials. Organic materials are full of nutrients. As mulch breaks down naturally with time and watering, it becomes, guess what? SOIL! It is like a slow release fertilizer that benefits the soil structure and adds nutrients.
The best best best part, mulch is FREE and usually considered a waste product.
Now let's not feel intimidated that we have to go hunting for a particular material called mulch. Mulch is, simply, dried organic material. Most abundantly this shows up as leaves, which are falling all around us every day. It can also be straw or crop waste from growing things like rice, wheat, millets, sugar cane and bananas. If you or a neighbor happens to have a chipper machine, then mulch is the wonderful bi-product of any hardy wood that gets put through the chipper. If the tree branches getting chipped were from nitrogen-fixing trees, even better.
Leaves from almost any tree make fabulous mulch. Pine needles and eucalpytus leaves are acidic, and thus should only be used if you are trying to lower the pH of particularly alkaline soils, and otherwise should be avoided. At The Odd Gumnut, with acidic soils lacking calcium, our mulch of choice is bamboo leaves, which are rich in calcium & silica, to slowly create more balanced soil.
For those on farms with chickens, straw material with seed heads can be first sent through the chicken coop and later used as mulch once they have scratched around and picked out the seeds.
Friends with balcony gardens, you can still mulch your pot plants and raised beds! AND you will have surplus dried leaves to add to your compost piles & worm bins, which really are the key to successful gardening at a terrace & apartment level.
As permaculturists, we know that priority is soil health. If our soil is hydrated, aerated, balanced and full of life, then our plants will be healthy, abundant and thriving without much extra effort.
Go get mulching. Got questions on what might make good mulch or bad mulch? Comment below!