Buying Straw

• Straw is widely available in rural areas, but hard to find in urban settings. Look at feed stores or nursery centers. Don't confuse straw with hay, though. Straw is the byproduct of wheat or leguminous crops and contains few weeds. Hay, on the other hand, is grown to feed livestock and contains weed or grass seeds. Buy certified weed-free straw when possible for mulching tomato plants.
  
  

Application

• Lay 6 to 8 inches of straw mulch around tomato plants when the plants stand at least 6 inches high. Apply the mulch only after the ground has warmed, because straw acts as an insulator. When applied too early, straw mulch reduces the soil's ability to warm in the spring. Tomato plants grow best in warm, slightly moist soil, and growth may be stunted in cold soils. Straw breaks down quickly in the soil. Reapply it once or twice during the growing season as the mulch wears thin.
  
  

Benefits

• Straw mulch promotes strong, vigorous tomato growth by conserving moisture. Weed growth is reduced, and gardeners spend less time weeding. As the straw breaks down, it improves the structure of the soil. Alfalfa straw adds nitrogen to the soil as it breaks down, providing fertilizer for the tomato plants. Dig any remaining straw mulch into the soil in the fall after harvesting the tomatoes.
  
  

Alternatives

• If straw is not available in your area, mulch tomato plants with untreated grass clippings. Spread a 1/4-inch layer of grass clippings on the soil around the tomato plants each week. The thin layer of clippings dries quickly and has the same benefits as straw. Do not use clippings treated with an herbicide, and don't apply thick layers of grass, which can become slimy and smelly. Black plastic spread over the soil in the spring warms the soil and can increase fruit yields and ripening rates. Do not dig black plastic into the soil in the fall.