Flower and Garden Beds
Cover your planting area with a one- to three-inch layer of compost. Incorporate it thoroughly using a spade, hoe, or rototiller with the top 5-6 inches of soil. If necessary, repeat this process one or more times. Rake the soil smooth and level. Water thoroughly after planting. Condition the soil this way every one to two years depending on overall soil quality. Remember, compost can also be used as mulch.
New Grass or Turf
Depending on the results of your soil test, apply a one to three inch layer of compost to the soil and incorporate it to a depth of five to seven inches. Apply seed to amended area then rake and water.
Apply a one-quarter to one-half inch layer of compost evenly to the grass or turf surface. Add the additional benefit of core aeration to your turf maintenance program if the soil is overly compacted – if it is difficult to push a screwdriver into your lawn it needs some aeration. The compost will stimulate new root growth.
Trees and Shrubs
Dig a hole two-thirds the depth of the root ball and at least twice as wide. Mix one part compost with three parts soil obtained from the planting hole. Place the tree or shrub into the planting hole and apply amended soil around the root ball. Water thoroughly then firm up the soil around the base of the plant. Be sure that the pH of your amended soil does not conflict with the pH requirements of your new plantings.
Mix twenty to fifty percent compost into your existing soil. Adjust your blend depending on the condition of the existing soil type and plantings that you will be installing.
Did You Know?
University of Washington research found the best plant growth results with 5 inches of pure compost added to the top 8 inches of existing unimproved soil for a total mixture depth of 13 inches, plus another 2 inches of compost as top dressing mulch. This soil improvement strategy increased plant biomass by between 580 percent and 860 percent without the use of chemical fertilizer. The improved soil also held twice as much water as the unimproved soil.