Useful Garden Projects for Autumn Leaves
Despite having spent many of my most recent years in the tropics, and despite having grown up in Louisiana, where the number of seasons is pretty wishy-washy, I’ve always kind of assumed that autumn could possibly be my favorite time of year.
My birthday is in right in the middle of autumn. It’s a time when the weather slowly cools down to a comfortable temperature, which seems better than slowly warming up from freezing as happens in spring. At least theoretically, the colors of leaves changing—something that hasn’t been the norm for me—sounds beautiful. There is Halloween, Thanksgiving, and all of those other harvest-derived festivals: apple, pumpkin, corn, beer, etc.
Now, I find myself in western North Carolina, not far from the Blue Ridge Parkway, which by many measures is the place to see autumn settle in. Showy golds, fiery reds, and vibrant oranges take over the Appalachian Mountains, and the roads become clogged with rubberneckers vying for time to see the leaves. It’s nothing short of magical.
Then, they fall. And, that, I’m coming to realize, is when I really like autumn. I’m a sucker for organic material, the type of guy who’ll rake up the neighbor’s grass clippings to put them to good use. While many people fret over and detest the leaves falling, I’m blown away by the potential. I can’t get enough of them. I’m dreaming of what they’ll mean to next year’s garden.
Pile of Leaves, Photo by Elliot Brown courtesy Flickr via CC 2.0
Why Leaves Are Great & How to Make the Most of Them
Leaves are top quality organic material. Having come from trees, many of which have deep roots, they are loaded with minerals. More minerals in our organic matter equates to richer soils in our gardens which means more nutrition and flavor in our food. Leaves are also very fibrous, and that helps to create a good humus. Humus makes clay soils airier and makes sandy soils more absorbent, so it’s a winner either way for the plants. From this annual harvest of leaves, I can make rich compost, excellent mulch, and first-rate soil conditioner.
Leaves (and needles) come in many shapes and sizes, and this can make a difference in how to deal with them. The general consensus is that its best to shred leaves. Shredding the leaves speeds up their decomposition, and whole leaves, particularly large ones, have the reputation of matting into an impermeable layer over time. Some trees—beech, oak, pine, etc.—can be particularly acidic, and the best way to counteract that is, like compost, to allow them to decompose first. Once the freshness of the leaves is gone, the acidity has moved much closer to neutral.
Shredding leaves, because it adds an additional step to leaf harvesting, is tepting to overlook, but it is time well spent. The mulch is better, and the compost happens more quickly. They can be shredded in a wood chipper, which adds the bonus of including small branches in the mix. Or, a leaf shredder (often a combined tool with leaf blowers), both devices that can be extremely useful when gardens are your game, is an obvious choice. They can also be shredded with typical lawn mowers by simple running over them a few times and collecting the results. Even a string trimmer and a large container, like a garbage can or an old storage bin, can work in a pinch.
Some trees, and consequently their leaves, have allelopathic qualities, which prevents many other plants from growing. Black Walnut, common in North Carolina, is considered one of the worst, and I dealt with a tropical offender, teak, while building gardens in Panama. Eucalyptus is another tree with allelopathic characteristics. When dealing with these, it’s best to avoid their leaves altogether and strive to minimize what accidentally gets put into the mix. However, if they are around, they can be processed separately and utilized for mulching areas far away from growing spaces where nothing growing is a positive thing, such as beneath picnic tables or on walking paths.
Compost Heap, Photo by Graibeard courtesy Flickr via CC 2.0
More Than One Option for Leaf-ing
Nowadays, people go out and buy their mulch and compost by the truckload, or more commonly and worse yet, by the plastic bagful. They use chemical soil amendments and import mixes for creating fertility garden beds. Sadly, many of those same people will gather up leaves in the fall and send them away in garbage bags to burden the landfills with useful, organic matter. Of course, in permaculture, that sort of thing couldn’t be further from our ethics, and I wouldn’t dream of it, particularly with so many high-quality leaves around. Here’s what I’m doing:
- Making Compost
Except for rare occasions when the Berkley method soothes my soil, I’m a lazy composter, a contented cold composter. I’m happy to pile stuff up, let it sit and rot for ages, and use it when nature has taken its course. Leaves work with both hot and cold methodology. The main thing to remember is that nitrogen material will need to be added. In this case, I’m layering kitchen scraps with leaves. It’s just going to decompose in its own sweet time.
On the other hand, I’ve made quick composts a few times with leaves, and they’ve worked really well. In this case, the leaves must be shredded, and the pile should be turned every couple of days. It’s more work, but for those in need of compost, it’s the answer for doing it in under a month at home. It might not be a bad idea to pile up a lot of leaves and get to that when the moment feels right.
- Making Mulch
Sometimes I feel like mulch is worthy of worship. I’m thinking about mulching before garden beds are even created. It’s like a blanket for the soil, sure, but knowing I won’t have to weed and water so much makes me feel warm and fuzzy inside as well. I was really enthused this past year when the 72-year-old man I work with/for, sent me to gather tarps full of leaves to spread over his gardens. He’d put a little circle of fencing in which he’d piled fall leaves each season. By early summer, it was time to mulch.
Though he has a more conventional approach than I sometimes do, i.e. tilling is still a large part of the program, he covers the entire garden in a blanket of leaves each spring once the crops have established themselves, and then again in the fall once everything has been pulled. Before planting next year, he tills all of the organic matter in. His organic garden puts out a serious bounty every year. I’ve put up my own little circular fence this year.
- Making Leaf Mold
Making leaf mold is somewhat like building a compost pile solely out of leaves. Once the leaves are gathered, it calls for no other work, requires no nitrogen element, but takes a lot of patience. Again, it’s just a pile of leaves in a circle of fencing. This time, they stay there for longer and don’t get nitrogen added. Where compost is good for adding nutrients and texture to the soil, mulch is good for protecting the soil, leaf mold is the bee’s knees when it comes to soil amending.
Essentially, leaf mold is what we find just above the soil on the forest floor, the layer where leaves—pure carbon—have been sitting for a year or three and have largely decomposed into a sort of spongy situation. This spongy stuff works similarly to peat moss or coconut coir, holding a lot of water. I’ve collected it in small quantities from the wild a time or two, but now I’ll be making my own.
- Building Beds
Finally, I’m just piling up leaves to prepare new garden beds. These gardens are going to be put together like slow motion lasagna beds. They began with trimming the grass for the last time and raking it into the spaces where the beds will be going. Then, after the leaves fall, I put a thick layer (a foot or more) over the grass clippings. This will sit over winter, breaking down.
In the spring, I’ll use a lawnmower or string trimmer to shred the leaves where they are, and I’ll add whatever nitrogen-rich material is around: spent coffee grounds collected over the winter, food scraps, early spring weeds, manure if I can muck some from a neighboring farm. I’ll cover that with a layer of newspaper or cardboard, mulch that with some spent hay or straw. It’s the beginnings of a really fertile, productive garden.
Autumn Leaves, photo by Brian courtesy Flickr via CC 2.0