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Building the Soil: Part Two - Layering, Mulching and Vermicomposting

Acorn and ThistleLayering your beds (sometimes also referred to as “lasagna gardening”) in the late summer/early fall is a great way to prepare an area for planting in the spring while building the soil below. Like cold composting, you just let nature take its course over the winter while the worms, fungi and bacteria do all of the work for you. It’s a great way to reclaim gardens overrun with weeds, or to start a new garden over an existing lawn without the backbreaking work of digging out or turning over the sod.

Layering can be done inside a frame for a raised bed, or just in a pile for a more freeform approach. I particularly like raised beds for a number of reasons (here’s a link to yesterday’s post, where I talk about my setup) and I think that if you’re just getting started, layering in a raised bed or two is a great way to get your feet wet.

Potato plants - 


First, frame in your bed. I recommend starting with a 4-by-4-foot square; we used untreated 2-by-6-inch cedar boards for ours. Then, put down a layer of cardboard or several layers of newspaper. If you’re doing this over a lawn, make your cardboard/paper layer a little bit larger than 4-by-4 feet, and put your frame on top of it. This will help keep the grass from creeping back up under the edges. Pro tip: Wetting down the newspaper as you go will keep it from blowing around while you’re working.

Once you have your frame and base situated, start layering on your greens and browns, alternating even layers several times until the box is completely full. Things will settle as they break down, so don’t be afraid to mound it up just a little bit. End with a layer of mulch (weed-free straw works great for this) and let it be until spring – with just a little surface weeding, your beds will be ready to go!

Mulching is an important part of soil building, as well.  In addition to retaining moisture in the summer and suppressing weeds for bare areas, using mulch (like straw or shredded leaves) feeds the soil as it breaks down. I do use wood chips as mulch around my trees and shrubs, but I avoid it in my veggie beds – mainly because it ties up quite a bit of nitrogen in the soil while it’s breaking down. Vegetables need a lot of nitrogen during the main growing season, and I’d rather leave it for them instead of the chips.

Applying mulch is simple: your goal is to create an even layer over the entire surface of a bed, around 2 inches deep. If you’ve been fighting a lot of weeds, put down a layer of newspaper before loading on the mulch. It will buy you some more time and help keep new seeds from germinating. Just avoid piling up the mulch around the stems of existing plants; while some, like potatoes and tomatoes, won’t mind, it’s also an invitation to some garden pests to come in closer. Slugs, pill bugs, millipedes … they all love mulch! That’s not a bad thing, though – in a healthy garden, even these guys have their place.

Mulch - Fotolia/GalinaSt 

Photo: Fotolia/GalinaSt

But what if you don’t have a lot of space, or garden on a balcony where having a compost pile or lasagna gardening isn’t practical? Enter vermicomposting, a self-contained bin system that uses worms to break down kitchen waste into a container gardener’s best friend: worm castings, which is just a nice way of talking about their poop. Worm waste, however you choose to refer to it, is a nutrient-rich soil amendment that can easily be used to top dress container plants. A “tea” can also be made from the droppings (or drained periodically from the bins themselves) that can be used to feed the plants while you water.

There are a ton of great DIY tutorials out there on how to build worm bins, and there are also a number of pre-fab kits available. Both of which make vermicomposting very accessible. They also require some protection from freezing, which is an added benefit to having an indoor setup. I don’t have a worm bin of my own yet, but I have been looking at plans to build one of my own. Between our house rabbit’s litter box and our regular kitchen scraps, a worm bin would sure be nice in the rainy winter months when I’m not particularly interested in slogging out to our main compost pile! If you’re interested in vermicomposting, let me know – I’ll happily chronicle my worm bin experiment in a series of posts, later this year.

Compost, layering mulching and vermicomposting are just a few simple ways (and certainly not the only ones) to naturally increase your soil’s health. Whichever route you go, the end result is the same: Feed your soil first, and it will feed you in return.

What about you? What kinds of things do you do, in order to build your soil?