Straw Mulch: Uses and Benefits

When you're starting a new lawn, planting a strawberry bed, or wanting to improve your soil, straw mulch is a practical, inexpensive choice. It's a natural product, packaged in two standard-sized, rectangular bales made up of flattened flakes bound tightly with string. Dimensions vary depending on the size of the machine used, but a small bale is a 2-string with the larger size sold as a 3-string. You can find straw mulch at home improvement stores, garden centers, and feed stores.

What Is Straw Mulch?

Straw mulch is a by-product of grain plants; rye, barley, oats, rice, and wheat. Threshing removes the grain and chaff, and stalks are baled and sold as mulch, animal bedding, and for other purposes.

Using Straw Mulch

Straw mulch is added to lawns, vegetable gardens, and small fruits. Its messy appearance doesn't offer an aesthetic appeal in ornamental flower beds, so landscaping use is limited. It is, though, an efficient insulator for winter protection—it breaks down rapidly and enriches soils which makes it ideal for edible gardens.

Straw Mulch in the Vegetable Garden

A small standard bale of straw covers about 80 square feet with a 2-inch layer of mulch. It's spread, usually by hand, and aids seed germination by keeping the soil moist. It also spreads easily around established plants. Bales are fairly lightweight; a 2-string weighs around 60 pounds. When the string is cut, the compacted straw separates into flakes that pull apart easily.

Use this mulch under squash, cucumbers , and melons to keep fruits off the ground. It prevents soft spots, molds, and rot that can sometimes appear in wet conditions. Use it in strawberry beds for winter protection. Straw insulates the roots and later keeps berries off the ground.

Add a layer of straw around cool-weather crops like broccoli, cabbage and cauliflower to keep soil temperatures down. It slows bolting and extends the growing time for better harvests.

Potatoes often break the soil surface, leading to sun exposure which causes solanine, a toxic substance, to develop. Straw mulch spread 3 to 4 inches deep and acts as a sunscreen around potato plants.

Straw mulch used around fruits vulnerable to soil-borne diseases, like tomatoes and peppers, limits splashback that causes the disease to spread.

Straw Mulch for Lawns

Straw is used almost exclusively to mulch new lawns or make repairs. Retained moisture supports germination and young shoots grow through when the straw is spread correctly. This is usually done by hand with smaller lawns or spot repairs. Contractors often use a machine called a thrower to distribute mulch evenly across the planting bed. To find out how much straw you need to cover a lawn area, websites are available to help you calculate. As the lawn fills in, mulch becomes less visible—it breaks down rapidly once mowing begins and any mats or clumps that remain can be removed by hand and composted,

Straw Mulch in the Landscape

Even though it's not visually appealing as a permanent mulch, straw is used in the landscape for winter protection. Hydrangeas, roses, ornamental shrubs, young trees, and any frost-tender plant can benefit from a layer of straw. Spread 3 to 4 inches at the base of the plant and remove it in the spring. For vulnerable shrubs, build a wire cage around the plant and pack it with straw for winter insulation.

Benefits of Straw Mulch

1. Inexpensive
2. Organic
3. Lightweight and easy to use
4. Breaks down easily and adds nutrients to the soil
5. Regulates soil temperature
6. Improves moisture retention and reduces evaporation
7. Aerates soil to improve the structure
8. Keeps fruit from soil contact
9. Prevents soil crusting
10. Winter protection

Tips for Buying Straw Mulch

Condition

Look for signs of moisture or the presence of mold or dark color in the flakes. Straw is often overwintered for seasonal sale in the spring. When stored properly, it has a clean, dry appearance and texture and should be odor-free with just a light scent. Flakes should be tightly packed and not separate within the bale.

Look for Local Sources

Check internet sites and newspapers for sources in your area. Grain is harvested during summer and local farmers may offer baled straw after processing. You can find out exactly what grain was threshed to make up your straw and possibly get a better price. Most commercially sold straw comes from wheat which can be seedy and more prone to matting.

Uniform Size and Shape

If you're purchasing multiple bales, look for uniform size and shape. Stalks of fairly even lengths and widths are less likely to mat and easier to separate and distribute. Grab the strings and give each bale a slight lift to test for even weight. The bale should feel compact without flake separation or loss.