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How to Mulch Garden Beds

By Jack S. Waverly ; Updated September 21, 2017
Properly mulched beds retain moisture and fend off pests and weeds.
rose bed. image by mdb from Fotolia.com

Mulching your garden beds can save you time, energy and money. Mulch also helps your garden to look its best and keep pests away from roots of young plants. Mulch adds protection from pests, controls weeds, moisture and temperature, improves the appearance of the garden and can add beneficial nutrients.

Measure the length and width of the garden bed by measuring from corner to corner. Break down the measurements of irregular beds into smaller squares and rectangles; add the totals from these smaller measurements to get the total area of the garden bed. Measure curved beds using the same method, but use the farthest points from the center of the bed to find the total area. Measure circular gardens using the radius.

Multiply the total size of the garden by the total depth of the garden in inches to get the total square feet of the garden. Divide the total square feet by 324. This is the total cubic yards of mulch required for the garden.

Choose either organic or inorganic mulch. Examples of organic mulch include bark, leaves and straw. Examples of inorganic mulch include gravel and stone or plastic. Use inorganic mulch when you don't need to hold moisture in the soil, such as in wet climates or with cactus. Use organic mulch when you need to control moisture or temperature, such as colder, wet climates.

Make necessary structural changes to the garden before mulching. Repair or replace damaged sections of the bed. Re-define borders with fresh edging. Build a raised bed. Level off the bed to avoid standing water. Improve the drainage by adding a layer of gravel or amending the soil.

Prepare the garden for planting. Test the soil with the pH test kit. This will help determine the acidity of the soil; this in turn helps determine the type of mulch you choose--pine straw and some barks may be more acidic than needed. Remove all dead material, plants and debris. Pull all weeds or intrusive grass, both in the garden bed and nearby, including crabgrass, Bermuda grass, English ivy, dandelions or other fast-spreading weeds.

Turn the soil. If you have organic mulch on the garden bed from the previous year, fold this into the soil to help fertilize the soil this year. Use a rototiller to break up the soil to a depth of 6 inches. This will aerate the soil and provide enough loose dirt for root systems to establish themselves. Put any fertilizer onto the soil. Mix the fertilizer into the soil. For smaller beds, use a hand tiller or shovel to turn the soil over.

Place all of the plants into their locations before applying the mulch. Water the plants at the base to a depth of 1 inch. Water the soil until it is damp but not wet. Water in the morning so the moisture doesn't evaporate before you get the mulch on.

Apply up to a 4-inch layer of mulch, recommends the University of Missouri. Keep the mulch away from the base of plants, trees and shrubs because this could hold moisture directly against the roots which can cause root rot. Shovel the mulch onto the garden in small piles across the entire garden. This will make the mulch easier to handle. Spread the mulch evenly with a rake.


Things You Will Need

  • Measuring tape
  • Edging
  • pH test kit
  • Rototiller
  • Shovel
  • Garden hose