Bare, exposed soil rarely exists in nature, so why should it be in your garden? Mulching with an organic mulch like straw will build healthy soil, conserve water, and help keep weeds at bay. In other words, it creates less work for you! Mulch is truly a gardener’s best friend!
It seems like all I’ve been doing lately is weeding and mulching. It’s taken longer than I wanted, but slowly but surely my garden beds are enjoying a nice layer of straw to help insulate the soil, form a layer that’s harder for weeds to penetrate, and retain moisture. I usually wait until plants are established before mulching, but I’ve recently learned about year-round mulching, which doesn’t sound like such a bad idea.
What is mulch? It’s basically any material (usually organic matter) that is used to cover exposed soil in the garden, and can be used for beds, containers, and even paths. Exposed soil can dry out quickly and be easily eroded by water and wind, so a covering helps keep it moist and healthy. The type of mulch you choose depends on the needs of the area you’ll be mulching, but I recommend staying away from unnatural materials like black plastic and choosing organic materials like straw, hay, decomposing leaves, rice hulls, or even dead & dried out weeds. Organic material will break down slowly and help add humus to the soil, making it richer and healthier for gardening.
You can mulch at any time of year, though I usually wait until plants are established so I don’t cover any emerging seedlings. It’s especially beneficial to mulch in the fall to protect the soil from the elements during the winter and warm it up a little for earlier spring growth. To mulch a bed, it may help to weed it first, then cover all exposed soil with a layer of 2 – 4 inches (or more) of your organic material. You can even mulch with compost, though it will break down faster, or a combination of materials. Leave a little bit of space around the base of plants or places where you’ve planted seeds.
Be careful to research the material you choose to mulch with and make sure you know what effects it may have on your soil’s pH. It’s a good idea to use an acidic mulch, like pine needles, around acid-loving plants like blueberries, azaleas, and rhododendrons. (I have learned from living in the redwoods to avoid using redwood needles in the garden – redwoods fight off competing plants by leaching substances from their needles that deter plant growth). Also be wary of wood chips – I would avoid using them in garden beds, but they work well for paths. Wood chips take a long time to break down, and in the process they leach nitrogen from the soil, which plants need. If you’re mulching with bark or wood chips, be sure to add a high-nitrogen organic fertilizer before adding the bark, and try not to mix them in with the soil.
To convert lawns and areas that are very overgrown with weeds into garden space, try sheet mulching. There are various ways to do this, but basically you’re covering the weeds or grass with a thick layer that will kill them and break them down into organic matter that benefits the soil. Start by laying down a layer of manure or compost to aid the breakdown process, then add a layer of recycled cardboard (make sure to avoid anything heavily printed, and peel off all the tape), followed by more manure and a thick layer of straw or hay. You can add wood chips instead of the straw, but they won’t break down as fast and with straw you can turn everything into the soil in a few months. It does take a while for sheet mulching to do its job, but it’s a great thing to do in the fall so you’ll have a perfect garden bed ready in the spring.
Almost anything can be used for mulch, so see what you can find locally. A few ideas are: spent hops from a local brewery, thick layers of recycled newspaper covered with straw or wood chips, rice hulls, compost, weeds that have been left in the sun to dry, straw or hay (try to find some without weed seeds) from a local farm, decomposing leaves, grass clippings, or even coffee grounds. Cocoa bean shells make an attractive mulch, but it can be lethal to dogs, so avoid it for front yard gardens where neighborhood dogs may walk by or if you or your neighbors have pets. Mulch can also be used for paths to keep them free of weeds (you may want to choose something with a slower breakdown time for this).
So if you want to protect and build your soil, reduce your garden’s water usage, and save yourself some work weeding, mulch is your answer. Your garden will thank you. Happy mulching!
Photo: My garbanzo and pole beans enjoy having a nice thick layer of straw mulch.