An easy way to separate your composting worms from the organic fertilizer is to screen compost. Putting the finished compost through a screen also makes higher-quality compost, because it’s fluffier and free of stickers, pits, sticks, and debris. Where do you get a screen? Can you make it yourself, or buy it? How do you screen compost?
Best Time to Screen Compost
When the weather is fair and you are prepping for spring planting, you will be looking for fertilizer. Any starts will need finished compost in their little pots to grow strong. The garden would love organic fertilizer mixed in with the topsoil, sprayed on as “worm tea” or used as a side-dressing. And lawns are praying for the nutrients and soil-friendly bacteria that “worm poop” provides.
If you have been composting faithfully with worms all winter, you should have built up a treasure trove of organic fertilizer in your worm bin. Some keep their worms cozy and productive indoors. Others leave them outside – those bins may need more time to bounce back if the temperatures were below freezing. When the worm bin has enough black material that looks like coffee grounds, the fertilizer is ready to harvest. Now you can get your screen ready!
How to Get A Screen
The trick to a composting screen is the diameter of the holes. You have a choice: either buy a screen, or make your own. Either way, Uncle Jim is here to help! Therefore, you really can’t go wrong if you keep reading.
Our 16-Inch Round Steel Compost Sifter is perfect for screening compost. The sifter lets organic fertilizer through, leaving worms and debris in the sifter. Specifically, the mesh openings are approximately 1/4 inch in size. Its galvanized steel framing and stainless steel sifting screen ensure many years of use with proper care. Just keep it clean and dry.
If you are handy and have the time, making a composting screen takes about 20 minutes. The payoff is that the screen will last many seasons. You will need scrap wood, a staple gun, hardware cloth with 1/4″ mesh or 1/8” mesh, and a clipper, plus a few more tools. Read our article about How to Make a Screen to Separate Worms from Compost, which includes an instructional video.
Harvest the Compost
If composting worms are mixed in with your compost, the screening process will remove them. You will add them back to the worm bin, ready to get to work again. Of course, you can use another technique to harvest your finished compost. For example, you can use a special tray-based composter designed for composting with worms. Most of the worms will be in the top bins, so the fertilizer in the bottom bins will be mostly worm-free. Or, read our article on harvesting your compost
How to Screen Compost
Screening compost requires a little time and patience. However, screening makes the compost “fluffier,” which means it can hold air better. It is also better at holding the right amount of moisture. Screened compost is very easy to work with versus compacted compost.
To screen compost, make sure the contents of the bin are not too damp. It should have the consistency of a wrung-out sponge. Find out what to do if it’s too wet. Take an empty container and put the screen over it. Use a trowel to move some finished compost into the screen. Shake the screen in a side-to-side motion. Worms and larger objects will stay on top of the screen. Finished compost will drop into the new container. See our article and video about screening compost for more details.
Now you are ready to reap the rewards! Get busy gardening with your composting worms’ incredible organic fertilizer.
Uncle Jim’s Worm Farm is the #1 supplier of composting worms and worm composting accessories in the USA. You can buy our worms year-round from our website. We carry the Red Worm Mix for composting, Super Reds for composting and fishing, and mealworms for pet and bird food.