Mulch⎯that is, material (usually organic) laid on the soil surface⎯is a tremendous ally in the garden. It helps protect plants during the growing season and soil in the off-season and adds organic matter, over time increasing soil microbial activity and improving soil health. Sheet mulching in particular is a very effective way to keep weeds under control and create new planting areas.
Of all the mulches out there, straw is our all-time favorite for edible garden use. It is functional and beautiful (especially when fresh-laid and golden), as well as very, very flexible. You can apply it in paths and in beds, in spring, summer, and fall. (You can lay it in winter, as well–but ideally, your garden would be tucked in before then!) You can lay it thick, move it around, and use it repeatedly; when you’re done using it as mulch, you can compost it to give it yet another useful life.
A few things to be aware of:
- Hay is not the same thing as straw. Straw is the stalks of grain plants–most commonly, wheat. Hay is used for feed, and contains viable seed-heads. Many of them. These will sprout and create a wheat carpet in your garden, and an innocent carpet can turn into a serious weed problem if not caught early.
- All types of mulch can smother small/young plants and cause rot on woody plant stems, so make sure to leave a “donut hole” around your plants, ensuring that the mulch is not touching them.
- A lot of people use straw as bedding for their chickens, and then turn that out into the garden. This is great in fall, to mulch beds that will be used for planting in spring. But don’t lay fresh chicken poo straw on areas that are currently growing things. It is too hot! Compost it first.
- We’ve occasionally encountered negative results from use of chemically-treated straw around town, so make sure you ask your feed store for organic straw and/or investigate thoroughly where your materials are sourced.
- Also, critters like to play and hide in mulch, so keep an eye out for slugs and snails and evidence of other visitors.
Here are a few pictures of straw-mulched areas that we’ve created with captions that describe how the straw functioned in each case.
For more ideas of how to use straw as mulch, check out this blog entry. But beware: this article refers to “hay” throughout, when I bet it doesn’t mean to.