Mulching Vegetable Gardens: Hay vs Straw

Lee Royer
Frederick County Master Gardener

I am a huge fan of Ruth Stout, the Mulch Queen, whose method, in short was: mulch is wonderful, put it everywhere, and even spread it naked if you like, just not during rush hour. Mrs. Stout recommended an eight inch layer of hay mulch between plants to discourage weeds, improve the quality of the soil, conserve moisture, preserve temperature, and create a pleasing appearance.

My vegetable garden is mulched with old or moldy hay and soiled bedding from stalls, which is our hay with added "pony pooh power". I’ve used hay for years with great results. Most garden authorities recommend using straw rather than hay but we make our own hay so I use what we grow following Mrs. Stout’s method, just not in the buff.

What’s the difference between hay and straw? Hay is a short word for grass, commonly Timothy or Orchard Grass, grown to proper height, cut at the peak of nutrition (ideally before it goes to seed), dried, bundled, and stored safely. The best hay is grown for sale to livestock owners because they value it and are willing to pay the premium price it commands. For various reasons, primarily weather related, it is difficult to cut hay without at least some of the grass going to seed.

Straw is the bare stalk remaining after a nutritious seed head, such as barley or wheat has been harvested. The stalks are then dried, bundled and stored safely. The best straw is sold as high quality animal bedding (think race horses). Farmers make every effort to harvest the grain from straw, leaving straw bales relatively seed free especially when compared to hay.

Knowledgeable gardeners should be able to make informed decisions on which is best for their needs. If your goal is simply to cover the soil, as for paths, then straw is fine. If your goal is to enrich your soil, then the nutritious hay is much better.

Using good quality of either is important, so learn basic evaluation of bales. Hay or straw may be excellent, good, or poor quality. Lesser qualities will have more seeds and weeds. If poorly made Certified Organic straw or hay may be worse than conventional bales in terms of seeds and weeds. Gardeners should keep in mind the lesser quality products are usually what they are offered because farmers can’t sell it at a higher price to livestock owners, especially Certified Organic.

Where to learn? Go on line to search out photos of hay and straw. This is only a start. How it feels, how it smells, and true color are essential factors you won’t be able to learn on line. Another idea is to attend local hay and straw auctions to see what brings the best prices. Talk to farmers; politely ask them to show you why they paid more or less. Westminster Livestock Auction has a weekly hay sale. Another idea is to study the results of hay competitions at local fairs, such as our Great Frederick Fair in September.

Ted Lambert, FCMG from Middletown, has a method for preparing bales which will work for either hay or straw. Ted says "I always solarize them by sealing moist bales in clear plastic then leaving them in full sun for at least 2 weeks. This seems to kill off most of the weed seeds."

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