When to Mulch

• Mulch your carrot plants after they have established, as suggested by Ohio State University. Thin the crop before mulching. Germination and growth may take up to two weeks after seeding, according to The University of Illinois Extension. Seedlings may not all emerge at the same time. Environmental factors, such as heavy rain, may delay or prevent germination. Failure to thin seedlings results in a crop of small carrots.
  
  

Thinning Out Carrots

• Gardeners plant two to three carrot seeds per 1 square inch. Thin carrot seedlings when they reach 1 inch in height, as suggested by the University of Illinois Extension. Pull out seedlings until there are one to two carrot plants per 1 square inch. With finger carrots, three seedlings may sprout in 1 square inch. Mulch the carrots immediately after thinning.
  
  

Mulch Types

• A number of mulch types are appropriate for the vegetable garden. Organic mulches, such as sawdust, compost, rice hulls, ground corncobs, animal manure, leaves and bark, may be used, according to Mississippi State University. Mulching with grass clippings controls pests like carrot flies, according to the Carrot Museum. Organic mulch contributes nutrients to the soil that benefit the carrot crop.
  
  

How to Mulch

• Spread mulch around the entire growing area. Apply a 2- to 5-inch layer of organic mulch around the carrot plants. The layer's thickness depends on the type of mulch used. Light, airy mulches, such as hay, must be spread to a 4- to 5-inch layer around the plants. Continue applying mulch to the carrot garden, as the organic material decomposes throughout the growing season.