Use and Application of Compost

Compost can be used to amend soil for lawns, gardens, ornamental plants, trees, and potted plants. The following application frequency and amounts are given as guidelines. Use your judgement and monitor your vegetation to determine the best rates for your environment. Application guidelines are given for the following areas:

Amend Soil with Finished Compost



On established lawns, apply compost once a year in layers 1/4 to 1/2 inch thick. Water well.

To prepare soil for a new lawn, till 4 inches of compost into 6 inches of soil.

Trees and Shrubs

Lay 1" compost around trees from one foot away from trunk out past the drip line. A 2" layer should be used for shrubs. Apply once per year.

To prepare soil for new shrubs, till the soil to a depth of 8 - 10 inches. The depth should be at least twice the width of the root ball. Apply a layer of 4 inches of compost and mix thoroughly into soil. If soil is very poor use 6 inches of compost instead.


Lay 1/2 to 1" compost on top of soil. If possible, till 2 - 4" into the top 10" soil. In large fields, apply between 900 and 1200 lbs. per acre as needed, depending on the current health of the soil.

To establish a new garden or prepare garden for planting, till the soil to a depth of 8 - 10 inches. Apply a layer of 4 inches of compost and mix thoroughly into soil. If soil is very poor use 6 inches of compost instead, mixing much of the additional compost into the top 3 - 4" of soil.

Potted Plants

Do not plant in pure compost. To root properly, plants must have the texture provided by soil. Your potting mix may be 1/4 to 1/3 compost. The remainder may be good potting soil. Many organic gardening books have "recipes" for potting soil which recommend a combination of compost, castings, potting soil, and other organic materials.

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Amend Soil with Organic Materials

This section covers soil amendment by addition of organic materials that are not yet fully composted. Such materials should not be added into soil which contains living plants -- see the discussion on nitrogen draft in the next section. Organic materials may be added directly into the ground and allowed to compost there if the ground will remain fallow for an appropriate time -- at least 6 months. For instance, organic materials may be tilled into a garden after the fall harvest and left fallow at least 6 months until spring planting. Because the appropriate mass is not achieved, composting in the ground takes longer than composting in a pile.

To prepare for a new lawn or garden, till 2 inches of compost into the top 6 inches of soil. Be sure to cover the ground with several inches of mulch.

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Mulch with Organic Materials

Mulch is matter that is placed on top of the ground (NOT tilled into the ground) as a covering. All bare soil should have a cover of mulch. Although some like to mulch for the appearance, the real purpose of mulch is to protect the health of the soil. Mulch lessens the effect of extreme temperatures. During summer months bare soil may reach 120 degrees F, but if that same soil were mulched, it would reach about 85 degrees F. In addition, mulch increases moisture retention, prevents top soil from washing away, and reduces soil compaction. One of the great benefits of mulch is that it shades out weeds. By covering the ground, weeds cannot get enough light to grow. The few that do survive are so weak, they can be easily removed. Before you lay down mulch, cover the ground first with newspaper. This will make it even harder for weeds to grow.

In addition to partially completed compost, there are many other organic materials which may be used as mulch: pine needles, various types of wood bark or chips, pecan or peanut shells, and shredded leaves.

Partially Completed Compost, Nitrogen Draft and the Forest Floor

There is controversy as to whether partially completed compost should be used as mulch. Opinions range from
"Never use compost that is not completely finished. After compost is finished, let it cure for several weeks to be sure the process is complete."
"One of the best mulches is partially decomposed compost."
Proponents against this practice claim that the compost will rob soil and existing plants to obtain nitrogen needed to complete composting. Other concerns are that there may be pathogens in the bacteria that have not yet been killed by exposure to the hot center of the pile, and that acids in the materials may be released as they compost and harm plant roots. Most experts agree that nitrogen will be stolen for composting if the materials are tilled INTO THE GROUND. The debate is whether or not this is true if the matter is laid on top of the soil. Other experts, including Howard Garrett (Texas Organic Gardening, p. 98) say that, as long as the partially decomposed matter stays on top of the soil, there is no damaging nitrogen draft.

For my own use, I believe it is good to mulch. I base this decision on the forest floor. The forest floor, from the bottom layer up, consists of soil, finished compost, partially finished compost, barely-started compost, and fresh organic materials. If it is OK for nature, it is OK for me. You must decide for yourself on this issue.


Place compost around trees or shrubs from one foot from trunk, extending out past the drip line. Don't place mulch right up against trunk. Recommendations as to the depth of mulch varies from 2 - 6 inches. I usually try to get it about 4 inches deep when I lay it down once a year. When I mulch the next year, I put the new mulch on top of the previous year's mulch, which is in the process of decomposing. An added benefit to mulching around trees is that the ground does not get compacted, nor the tree trunk damaged from mowing and weed-eating.

Annuals and Perennials

Partially completed compost can make a mulch for ornamental plants. Recommendations range from 1/2 to 3 inches over entire bed. Don't place mulch right up against plants.


Partially completed compost can make a mulch for food crops. Apply 1/2 to 1 inch over entire bed. Don't place mulch right up against plants.

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Application of Worm Castings

Earthworm castings are even richer in nutrients than compost, so they must be used more sparingly. Castings are rich in bacteria, calcium, iron, magnesium, and sulphur and 60 other trace minerals. N-P-K is about 1-.1-.1 according to one source.


Apply castings once per year at 20 lbs. per 1000 square feet.

Annuals and Perennials

Put a small handful of castings into each hole as you plant. Four times a year, apply castings at a rate of 10 lbs. / 1000 square feet -- OR -- once per year at 20 lbs. per 1000 square feet.

When preparing beds, mix 6 inches of compost into the soil, then mix in castings at the rate of 20 pounds per 1000 square feet.


When germinating seed, place in bottom part of soil. At transplanting time, put a small handful of castings into each hole as you plant. This is also true for bulbs, vegetables, herbs.

Potted Plants

Mix a small amount of earthworm castings to your potting soil. Remember that castings are very potent, so don't overdo it. No more than one-fifth of the ingredients should be castings.

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Compost Tea

Non-aerated Compost Tea

Put compost in a burlap bag and set in water. Agitate every once in a while. In a few hours to a few days (depending on amount of compost and water) you will have compost tea. You can make compost tea in containers from the size of a watering can to the size of a garbage can, or larger. For use, the tea should be a light amber color. If it is darker than that, simply dilute with water. Pour a pint each around shrubs, water your lawn with it, soak seeds in it before planting.

The compost used to make the tea is still potent. Use it as you would use fresh compost.

Aerated Compost Tea

A discussion of the benefits of aerating compost tea are available in pdf eBook format in a free book excerpt from booklocker.com. The full eBook is available for purchase from that site as well. Though making aerated compost tea is just a bit more trouble than making non-aerated, the benefits are greater.

The full eBook gives instructions for building a brewer for less than US$15, making the tea (with safety instructions), and applying the tea. See How to Build Your Own Compost Tea Brewer and Brew Compost Tea at Home! for more information.

Online Stores
Compost Tea Brewer
Build a brewer with a bucket and less than $15 worth of components, and make aerated compost tea.
Composting the Holidays
Compost fall leaves, hay bales, holly wreaths, pine trees, etc. Compost pumpkins (food waste) in a compost pile.



  1. Build a Compost Pile: Basics
  2. Build a Pile: Advanced
  3. More on Building a Pile
  4. Compost Ingredients
  5. ** Use Finished Compost **
  6. Leon's Composting


  1. Worm Composting
  2. ** Use Finished Castings **

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Return to Compost Site Contents

Make Your Own Brewer
Brew Compost Tea at Home!

eBook $9.95
Download Now!

Make Your Own Brewer
Brew Compost Tea at Home!

eBook $9.95
Download Now!

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