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How to Add Compost to Soil in Back Yard

By Contributing Writer ; Updated September 21, 2017

Compost improves soil by adding nutrients, nitrogen and organic matter. It can improve almost all soil types, with the exception of loam soils, which are nearly perfect. Compost increases a soil's water-holding capacity, while allowing the soil to drain excess water quickly. Compost also adds nitrogen, potassium and phosphorus, the "big 3" needed for plant growth, plus micro-nutrients like calcium and magnesium that help plants thrive. Good, finished compost looks like dry brownie mix. It is dark brown with a crumbly texture and has an earthy, slightly sweet smell.

Established Lawns

Fertilize lawns with compost in early spring, just as the grass begins to turn green. Choose a dry day with little wind and temperatures between 50 and 60 degrees F.

Remove debris from the area you wish to fertilize by raking leaves and discarding branches. Fill in any holes.

Screen the finished compost to remove clumps and pieces of incompletely composted material. Place a compost screen over a wheelbarrow and shovel compost onto the screen. Shake the screen or run your hand through the compost forcing the smaller particles to fall through the screen. Replace incompletely composted material back in a working compost pile. Keep screened compost separate from unsifted compost.

Adjust the flow rate of your broadcast spreader to broadcast 1 cubic yard of compost per 1,000 square feet, or to broadcast enough compost to form a 1/3-inch layer.

Fill the broadcast spreader with screened compost. Push the broadcast spreader slowly over the lawn to distribute an even layer of compost over your grass.

Gently sweep your lawn with a broom, either a push type or regular, to move compost off the grass down to the soil.

Apply 1 to 2 inches of water to your lawn. Watering after fertilizing keeps compost from blowing away and helps move compost from grass blades to the soil.

New Lawns

Seed or use sod to establish new lawns when both daytime and nighttime temperatures remain above freezing. The best time to establish a new lawn is in mid-to-late spring and early fall when growing conditions are perfect for grass.

Remove weeds and debris from the planting area and rake the soil smooth.

Apply 3 to 4 inches of compost over the planting area.

Till the compost into the top 4 inches of soil and rake smooth.

Apply grass seed or sod according to package directions.

Flower Beds, Trees and Shrubs

Cover new flower beds, gardens or areas that are planted with annuals with 3 to 4 inches of compost. Till into the top 6 inches of soil and gently rake the bed smooth. Plant as usual.

Surround established perennials, trees and shrubs with 2 to 3 inches of compost in spring. Gently mix the compost into the top 1 to 2 inches of soil or use the compost as a mulch. You can do this several times during the growing season depending on the plant's needs.

Mix enough compost with the soil removed from holes when planting trees, shrubs and perennials to make a 50-50 compost-soil mix. Back fill the hole with this mix.


Things You Will Need

  • Compost screen
  • Shovel
  • Wheelbarrow
  • Broadcast spreader
  • Broom
  • Rake
  • Tiller
  • Ruler


  • Test your soil regularly, as some nutrients may be depleted at a rate faster than compost can replace them.
  • Broadcast spread compost over lawns by hand rather than use a broadcast spreader. Take a handful of compost and, using an arcing motion, gently release it over the area in front of you. Take a step backwards to spread more.
  • Use compost as an organic mulch. Apply 1 to 2 inches more around plants than you would shredded bark.


  • Always use finished compost. Unfinished compost may temporarily take nitrogen and other nutrients out of the soil as it is decomposing.
  • Don't fertilize established plants in late summer or fall, as this will encourage new soft growth that may be killed over the winter.
  • Rake mulch away from the area you want to apply compost. Reapply mulch after the compost is spread around the plant.
  • Do not use compost or other fertilizers around plants that need a lean soil. Plants like lavender, cacti, aloes and ice plants will die if over fertilized.