Look up! Right now, the secret to a stronger, healthier garden is falling all around you. Autumn leaves are nature’s mulch, soil conditioner and fertilizer, all in one small package. And the only thing you need to do is scoop them up and add them to your soil or compost bin.
Using leaves to improve your garden is perhaps the most underutilized of all gardening techniques. People spend hundreds of dollars every year buying compost, mulch, soil amendments and fertilizers, when they could simply rake up the gold (and orange and red and brown) laying in their yard.
Incorporating leaves into the soil mimics what Mother Nature does in the forest. Leaves drop and, with time and weather, break down to become leaf litter. This litter adds microbial life to the soil, it improves its tilth (structure) and water-holding capacity, it helps prevent erosion and it provides a bit of phosphorous and potassium (among other nutrients).
When you use leaves in your garden, it gets these benefits, too. And did I mention they’re free?
Go For The Mold
As wet leaves decompose, they turn into this marvelous substance called leaf mold. This dark, crumbly material looks and smells like compost, which is essentially what it is: composted leaves. It’s good for the soil, which means it’s good for your plants. Leaf mold is your goal.
How To Shred Them
To speed up the process of making leaf mold, the leaves need to be shredded into small pieces. Depending on the tree species, intact leaves can take a long time to break down, longer than a single winter. Plus, piles of whole leaves mat and shed water, keeping rain and snow from reaching the soil. The smaller the pieces, the quicker they rot.
You can chop them up a number of ways. A shredder is the easiest and most efficient, of course, but there are others. You can mow over them with a mulching mower that has a bag attached to collect the pieces. Or you can put piles of leaves inside a 55-gallon garbage can (to ¾ full) and use a string trimmer to break them up. Whatever method you choose, be sure to wear work gloves and eye protection.
It’s easier to shred leaves when they are dry, not wet.
How To Use Them
Add to your garden beds. There are two ways to use shredded leaves in garden beds: one is as a mulch, the other as a soil conditioner.
In perennial beds, where it’s difficult to dig without disturbing plant roots, use the chopped leaves as mulch. Pile it no more than 3-inches deep. Take care to keep the mulch from touching the crowns, stems or trunks of herbaceous plants, trees or shrubs, as such contact can be a vector for pests and disease.
You can use them the same way in your vegetable beds, where the mulch will keep bare soil from eroding. Mixing the leaves into the soil not only speeds decomposition, it improves its consistency or tilth, lightening it so there’s less resistance for a plant’s growing roots. The leaf mold also holds moisture, so you’ll need to water less.
Condition your lawn. To condition your lawn, just mow over the leaves laying on it without the bag attached. Mow at a three inch height, and make sure the discharge chute blows the clippings onto the lawn, not impermeable surfaces. If the leaf pieces are still big, mow over them again. The small pieces will break down over the winter, and combined with the grass clippings, will add nitrogen and carbon to the soil.
Incorporate into your compost pile. This is the easiest way to use them. Even if the leaves are dry, you can add them to your compost pile. To cook properly, a compost pile needs a lot of dry “brown” material, the source of carbon, to mix with “green” material, the source of nitrogen. Leaves are ideal for this purpose.
Protect overwintering container plants. This is the one time whole, intact leaves work to your advantage. Hardy plants such as trees, shrubs and perennials can be overwintered outdoors in their containers, but the roots need to be insulated from freeze/thaw cycles, which can be fatal. Covering the plants with leaves protects them from temperature fluctuations. You’ll need a lot, preferably dry ones.
Group all the plants together in one protected spot and pile the leaves over, under and around the plants, covering not just the pot but the entire plant. Don’t pack them too tightly; air and moisture need to reach the plants. You can cover everything with chicken wire to keep the leaves from blowing away, if necessary.
Do you have too many leaves to use right away? Trick question! For gardening purposes, there’s no such thing as too many leaves. Store them in large plastic or paper leaf bags. Or rake them to an out-of-the-way spot in your yard and cover with a tarp. The moisture that collects under the tarp will help the leaves rot. You’ll find uses for them next spring and summer.
Don’t throw free money away. Instead of bagging up your leaves to put out with the trash – or worse, burning them – use them to create a healthier, more resilient garden.