Gardeners already understand the importance of mulching flower gardens. Mulch helps regulate the soil temperature, improves water retention, and prevents soil erosion. But should you mulch your vegetable garden? If so, with what?
Studies show that mulching your vegetable garden can increase (or even decrease) yields by as much as 30%, so as important as mulching may be, the type of mulch used is an even greater factor contributing to gardening success. While there are many types of mulch that work well in vegetable gardens, here are four popular options based on crop type.
Black plastic
Black plastic is a good mulch for crops that love heat such as tomato plants, eggplant, peppers, melons, cucumbers, squash, and potatoes. Lay plastic in early spring to help warm up soil temperatures, potentially extending your gardening season. Plastic will require extra security to remain in place during windy times.
The major concern with plastic is ensuring adequate watering, since water cannot penetrate the plastic (this is an example of how mulch can decrease crop yield). Take note of the ways in which your plants can get water: Are you in the rainy season? Do you have sub-mulch irrigation? If not, you may want to remove the plastic mid-summer to allow plants to get extra moisture during hot months.
Other downsides to using plastic? It’s not biodegradable, can be unattractive, and can be difficult to handle. Avoid plastic altogether in extra-hot regions.
Leaves
A guaranteed-free mulch. Leaves are an ideal mulch for broccoli and peas, which prefer cooler temperatures. The permeability of leaf mulch can actually lower soil temperatures by 20-25 degrees; be sure not to mulch your heat-loving plants as well. Since soil may experience a decrease in temperature, don’t apply this mulch type until the soil has reached an adequate temperature, perhaps mid-summer.
Hopefully you have a large stock of leaves available, as this type of mulch will blow away easily. Once wet, leaves mat down into an unsightly soggy mess, so the best option is to shred them before applying.
Burlap
Burlap bags (such as those that hold food products like coffee beans or rice) are an efficient mulcher for a variety of crops including blueberries and carrots. The advantages to burlap are both cosmetic and practical. Burlap can give your bed a clean, polished appearance. If secured properly, it will stay put with little effort, even during wind. It also allows plenty of moisture through, making this a great all-season mulch choice. It’s also an easy way to protect against occasional early frosts.
Burlap can be expensive for large gardens, so ask for donations from local vendors. Due to its permeability, it is not an effective weed barrier, so burlap lacks as a mulch in that respect.
Another option? Try growing potatoes right in burlap bags. And don’t forget, burlap is compostable!
Straw
Straw is effective for both delicate crops like leafy greens and robust potatoes. It should be applied in mid-summer once soil has reached an ideal temperature. Straw may actually reduce the temperature of soil by 20-25 degrees, so consider applying in layers so as to not shock crops. Straw can also be used in the winter to protect soil.
Why might you not want to use straw? Two major reasons. One, unless you have access to free straw, this mulching method can be quite expensive for larger areas. Two, if you’re not a diligent weeder of your vegetable garden, you may find that you cannot keep up with the growth of oats, unless you use seed-free straw. Like any mulch (but even moreso with lightweight straw), it may blow away and need reapplication.
For more resources, visit:
http://www.ext.colostate.edu/mg/gardennotes/715.html
http://extension.uga.edu/publications/detail.cfm?number=C984
Creative Commons Flickr photos courtesy of USDAgov, Mike Linksvayer, benhosking, and jessicareeder.
Good site. Lot of information. Thank you..
There are so many more good (and cheaper) mulching materials. Pine straw is excellent for both flowers and vegetables, and looks beautiful as well (that myth about pine straw being too acidic has been dispelled). Black plastic (or red if you’re a tomato grower) is fine but it adds nothing to the soil and is expensive. Instead of expensive straw that is full of seeds, try old hay. Old rotted hay is wonderful, full of nutrients and composts right in the garden while it mulches. Grass clippings (fresh) add nitrogen to the soil as well as deterring weed growth, however, make sure that they don’t touch the plants you actually want to protect with them, as they compost fast and easily and can literally burn your plants. Cardboard is also a wonderful and free first layer mulch. Water can go through it but light cannot, so no weeds can germinate – and as an added bonus, earthworms love cardboard. They come up to eat the glue in it and enrich your garden soil. It will rot easily and add nutrients to your soil as it does. As for leaves, use them, swipe bags from the side of the road, rake your own, use that shredder attachment on your leaf blower (you know, that big weird vaccuum thing that you stuck in the garage and never used). It’s pure fertilizer for your garden and will stop you from weeding as well. Be creative with your mulches and you’ll save tons of money doing it. Lay on mulch thickly (an 8 inch layer to start is good – keep adding!) and, if you see a weed poking through, simply lay more on top of it – weeds can’t grow in the dark! Your back will thank you for not having to weed and your garden soil will be much happier, too.
I found a weird mulch, if you can call it that, which does not degrade and stops water evaporation, it is gravel. The plants need watering much less frequently.
I have more conventionally dug straw into my beds and it makes a big improvement, as I was gardening on builders rubble before.
@ Claire Cheskin:
Stone mulching was/ is a method used quite a bit on Easter Island. One of the benefits of it is that the stone cools overnight, and condenses moisture from the air: Easter Island has few or no streams, so the moisture helps add to whatever rainfall happens there.
The islanders in the past had vast areas covered with stone mulch. They worked with hoes and sticks, or similar hand tools, so weeding around the stones wasn’t the problem it would be with machinery.
I first learned about this tradition this past winter, and was very impressed by it, and think it could be a valuable permaculture tool I have since heard from friends that they have also noticed the dew collecting and larger yields in gardens they have patches of stone mulching on.
On Easter Island, the stones also gave some shelter from the strong winds to young plants (trees included).
In some locations, trees were… and are again… being planted in pits several feet deep, lately in field tests by local scientists studying pre-contact agriculture.
Im a big fan of a lucerne mix for mine, particularly in the veggie patch! I also use it to make sure that my garden doesnt suffer too much from dryness during the hot Australian summer! http://bit.ly/1Gj4J1C
Im in AZ and just planted from the organic seed i bought, i planted tomato,(beefsteak kind) brocolli. okra, squash(kombacha) and I transfer it to a 2×2 raised bed, and the other to couple of tires. i applied pine mulch from my pine tree although i dont really know why, i just heard it. anyways i water every morning, and some in the afternoon after sun down.. Im an amateur here i still learning and dont know… any advise will be appreciated. thank you.
What about slugs?
Is cardboard ok in the vegetable garden for mulching.