Garden Mulch Calculator

Two inches is plenty. It suppresses weeds and holds moisture without keeping the soil cold in spring or giving slugs somewhere to live right next to your seedlings. Ornamental shrub borders can take 3 inches; vegetable beds should not.

Straw, shredded leaves or compost. All three break down within a season and feed the soil, which is what you want in a bed you replant every year. Bark and wood chips last longer but are better suited to permanent plantings — they are awkward to work around annual crops.

A small square bale spreads to roughly 10 cubic feet, which covers about 60 square feet at 2 inches deep. A 12 by 4 foot bed needs about one bale. Bale sizes vary considerably, so treat that as a starting estimate.

After, once seedlings are established and the soil has warmed. Mulching cold spring soil keeps it cold and slows everything down. For direct-sown crops, wait until the seedlings are a few inches tall so you can mulch around them without burying them.

Measure the length and width in feet at the widest points and multiply them. For an irregular bed, break it into rectangles, circles and triangles, calculate each one separately and add the results together. Rounding up slightly is safer than rounding down.

Bulk is almost always cheaper per cubic yard once you need more than about 1 cubic yard — roughly 14 bags. Bags win when you need a small amount, have nowhere to dump a pile, or want to spread the job over several weekends.

A half-ton pickup can usually carry about 1 cubic yard of light material like mulch, but only around half a cubic yard of wet soil or gravel because of the weight. Check the weight figure above against your vehicle's payload rating before you load up.