Can You Compost Straw and Hay?
Yes. Straw is a classic brown, roughly 75:1 C:N, that keeps piles airy. Hay is greener and richer in nitrogen but may carry seeds. Chop both if you can, and ask the supplier whether the field was sprayed with a persistent herbicide.
At a glance
| Home compost pile | Yes |
|---|---|
| Green or brown | Brown (carbon-rich) |
| Carbon to nitrogen | about 75:1 (straw) (approximate) |
| Moisture | Dry |
| Prep | Chop into small pieces |
| Worm bin | Yes |
| Bokashi | No |
How to compost straw and hay
Loosen flakes and chop or mow straw into shorter pieces, then layer it with greens at about 2–3 parts straw to 1 part greens. Hay needs fewer greens alongside it. Straw is ideal for covering fresh kitchen scraps.
Farms and feed stores often sell old or spoiled bales cheaply. Ask how the field was treated before you buy.
What goes wrong
Long, dry straw sheds water and can sit unchanged for months. Wet it thoroughly as you add it and chop it shorter. Some hay and straw carry persistent herbicides, such as aminopyralid, that survive composting and damage tomatoes, beans and potatoes.
Worm bins and bokashi
Worm bin: Chopped straw makes good worm bin bedding mixed with shredded paper or cardboard.
Bokashi: Straw and hay aren't bokashi material, but they make a good cover when you add fermented bokashi to a pile.
This counts as a brown. Adding a lot of it? Check the balance with the compost mix calculator.
From hopcompost.com/can-you-compost/straw-and-hay/ · General guidance, not professional advice.
Frequently asked questions
What's the difference between straw and hay for compost?
Straw is the dry, hollow stems left after a grain harvest: carbon-rich, with few seeds. Hay is dried grass or legumes cut for animal feed: more nitrogen, often with seeds.
Can you compost moldy hay?
Yes. Spoiled hay composts well and is often cheap. Wear a dust mask when handling it, since the spores can irritate your lungs.
How do I test hay or straw for herbicide residue?
Grow a few pea or bean seeds in pots of compost made with it, next to pots of plain potting mix. Cupped, curled or twisted new leaves suggest herbicide residue.