Compost International
Saving the earth one compost heap at a time




 This is the easy part.  You just spread it around!

 For any application needing fine particles, you will want to sift the compost.  This can be done with any type of screen material fixed to a frame.  They come in various shapes and sizes, from 14” metal rings with mesh bases to litter box like plastic pans with interchangeable screens of different gauges.  Most commercial sifters use a ½ or ¼” mesh.

My sieve/sifter is the lid of a galvanized garbage bin through which I laboriously hammered concentric rings of holes.  The holes are not very big so I get a very fine product. 

 The scientists offer some caveats, and warn that you should only use mature or stable compost. My biggest gripe with the United States is that as soon as there is the slightest chance that something may, under certain circumstances, be dangerous to a very small population, a law is passed to make it illegal.  No one is permitted to take even the smallest calculated risk. With that off my chest, let me say that there may be some negative effects when using immature compost.  The best known of these is that immature compost can temporarily rob the soil of nitrogen.  That is why you should wait a few weeks between amending the soil with young compost, and planting.  In those few weeks, the balance changes and microbes begin to release nitrogen.

Immature compost is not good for seedlings because it may contain competitive seeds, it may still be absorbing nitrogen and it may still contain phytotoxic (poisonous to plants) elements such as volatile organic acids and salts. For these reasons commercially prepared compost is carefully regulated as to when it may be used in nurseries.

On the other hand, immature compost applied as a mulch provides all the benefits of mulch – temperature control, moisture control, – and seems to have a mild herbicidal effect, thereby adding to the other benefit of mulch, namely, weed control.

Suggested uses for varying degrees of maturity in compost are:
Very mature compost is a well-cured compost, which has c
ompleted the rapid decomposition process, the original materials are unrecognisable and there is no odor.  When screened (sifted) this is perfect for seeds and seedlings. Many resources suggest that it can also be used as part of a soil and peat-based mix for container plants.  I have mentioned my aversion to peat, and I would use perlite or similar to lighten the mix.

It is very good for top dressing a lawn or dense planting such as groundcover, where you can scatter the very fine product on top of the plants and then shake them to drop it down to soil level.

Mature compost has undergone some curing. It is unlikely to produce odors, and has minimal impact on nitrogen in the soil. It can be used when planting trees, shrubs, perennials, and to prepare a bed for annuals. Good also for general field use (pastures, hay), if you are into farming, or for vineyards.  This is the compost to use for you vegetables.

Immature compost may produce odors and still contains some recognizable materials such as stalks and twigs, large leaves. Its main uses are to amend fallow soil, and to add organic matter to depleted soils, with the assumption that the area will be left unplanted long enough for the curing process to complete. Immature compost is also a very good start for the next compost pile. As mentioned above, you can successfully use it as a mulch. My gardening guru in Rome used to say: “You don’t have to dig it in: the worms will take it down.”  And they do.

 A word here about mulch.  There is no one thing that is mulch, although there are many materials that can be used as mulch.  Straw, woodchips, plastic sheeting, shredded newspapers are just straw, woodchips, plastic sheeting and shredded newspaper until you decide to put them to good use as a great way to preserve moisture and soil structure, while keeping down weeds.

Compost tea.

Compost tea is easily made by soaking or steeping compost in water. The resulting compost tea is used for either a foliar application (sprayed on the leaves) or applied to the soil. Many websites and books insist that it needs to be artificially aerated in order to be effective.  In fact there is a minor industry supplying all kinds of  equipment with which to aerate the tea.

However, the Co-operative Extensions of both Maine and Washington maintain that additional aeration is not necessary.

Compost tea is a great way to make a little compost go a long way, and the foliar application in particular, has good anecdotal and research-based evidence of disease fighting qualities, including against the dreaded late blight.

On the purely anecdotal level, in 2009 when upstate New York had serious late blight, I surveyed our Garden Club members.  In all but three cases, tomatoes had been wiped out, more or less overnight.  The three  exceptions did not escape completely, but our compost-fed tomatoes survived for the entire season, producing until the end, albeit in limited quantities.