Have you ever looked into your compost bin and asked yourself, “Is this really compost?” Well, if it doesn’t look like banana peels, eggshells, onionskins, and apple cores any more, it’s compost. When your whole pile looks like soil or humus instead of food scraps, it’s time to harvest.
One way to harvest compost is to dig it out of the pile and spread it on a tarp outside to dry. Compost is easier to spread evenly when it’s dry. Some gardeners screen their compost, tossing clumps into a new pile for more composting.
Once your compost is ready, you can use it in any number of ways.
Add compost to the soil
Compost improves soil aeration, enhances the soil’s ability to hold water, and slowly makes nutrients available to plants. Add up to six inches of compost to the soil each year, or add a little bit to a seed furrow or planting hole. The poorer the soil the more compost it needs. You can never add too much compost!
Make potting mix with compost
Screen the compost through a ½-inch mesh and mix it with equal parts sand (or perlite) and soil. You’ll have a well-drained potting soil that is high in organic matter. Use it to repot houseplants, in container gardeners, and as a thin layer on top of the soil of houseplants.
Mulch with compost
Two to six inches of compost spread around trees, shrubs, and other plants will keep weeds down, conserve water, help prevent erosion, and attract earthworms. Unlike some mulches, which can remove nitrogen from the soil when as they decompose, compost is already decomposed. In fact, compost actually adds nutrients to the soil. As with all mulching materials keep the compost away from plants stems and tree trunks.
Make compost tea
Composite tea is basically liquid organic fertilizer, providing plants with nutrients and beneficial microorganisms. To make your own compost tea, put some compost in a cloth sack and tie the sack shut. Place the sack in a bucket of water and let it seep until the water is the color of light tea. You can water houseplants, flowers, and vegetables with this healthful brew by pouring tea in the soil or spraying it on the leaves as a foliar feed. Compost tea doesn’t last long, so just make what you can use in a couple of days.
Spread compost on the lawn
Four to six inches of compost tilled to five to eight inches deep is excellent preparation for a new law. Apply a thin layer (less than an inch) on established lawns once a year. Compost reduces a lawn’s need for food and water and adds organic matter to the soil.
In addition to improving your soil and making your plants grow better, composting benefits the environment. When you send your scraps to the compost bin instead of to the landfill, you reduce landfill needs as well as the costs and pollution associated with trash hauling. And by using compost instead of chemical fertilizers you do your part to keep toxins out of the air and water.
There’s no doubt about it–making and using compost benefits everyone.
Want to learn more about composting?
If you want to find out more about the miracle of compost, check out these websites:
The City of Davis, California features this Backyard Composting Guide.
Santa Cruz County has a definitive guide on How to Use Compost.
If your main question in life is Why Use Compost – here’s a handy pdf file to help you answer that question.
This may be a silly question(s), but here goes. If I’m adding to my compost pile continuously, turning it regularly and the process is progressing nicely, when is it actually ready to use? I feel like I’m going to get a lot of undigested material mixed with my “ready” compost. Do I screen it and add the un-composted material back into the bin? Does the finished product just sift to the bottom naturally? Do I keep multiple piles at different stages of done-ness?
@thom
When continuously composting, one way to handle it is to just stop adding for a few weeks (or begin adding to a different bin or pile) until the last fresh materials are finished. You can also screen it and throw the other stuff back in, just like you mentioned. There’s not really a wrong answer, because it’s more about what you like better or is easier for you to do.
If you’re using a bin that has a door at the bottom, you can typically just keep throwing stuff in the top and scooping the finished material at the bottom. With a pile, it’s often a little harder to get the bottom stuff out that way.