If you like to add homemade compost to your potting soil mixes, or you want to use compost to side-dress your plantings, you will generally want to use a nice, sifted compost without any large chunks or bits of material that haven't fully decomposed. The easiest way to get this fluffy, sifted compost is to use a compost screen.
You can purchase compost screens through some garden catalogs, but it costs literally pennies to make your own, and you can make it whatever size you want. Maybe you would prefer a small one, one that's easy to just hold up over a bucket and sift compost into it. I have one that fits perfectly so it can sit on top of my wheelbarrow, and I can shovel compost right into it, then sift it into the wheelbarrow to take to the garden.
Here's what you need to make your own compost screen:
- Two by four lumber (I used pine, though you could use cedar if you want it to hold up longer), cut to whatever size you want your screen to be.
- Hardware cloth. This looks like chicken wire, but with squares. You'll want a small gauge -- I made mine with 1/2 inch hardware cloth, meaning the squares are 1/2 inch in size.
- Galvanized screws and a drill/driver.
- Staples and a staple gun.
- Narrow trim, such as screen molding, to cover sharp edges.
- Wire cutters
Once you've figured out what size you want your compost screen to be and you've cut your lumber to size, make a four-sided frame with the lumber. Set the pieces up on edge (you want the screen to be deep) and screw the corners together. You can get fancy and miter them if you want, but simple butt-joints work just fine.
Once your box is built, cut your hardware cloth to size. you want it to be about an inch larger on all sides than your frame, so you can wrap the screen up the sides and staple it. The easiest way to measure this is to just place your frame on top of some of the hardware cloth and mark around it. Then cut the hardware cloth with wire cutters. It would be a good idea to wear gloves -- it is sharp.
Once your hardware cloth is cut, bend it up around the sides of your frame and staple it in place. The best way to do this is to staple one side, then pull it as taut as you can and staple the opposite side. Then work on the last two sides.
Now you have a serviceable compost screen, but it has a lot of little sharp, ragged edges where the hardware cloth ends, and they are right on the sides of the screen, where you'll be holding the sifter screen. To cover them, cut small pieces of trim, such as screen molding or lattice stock, and nail or screw it onto your frame to cover all of those edges. Again, you don't have to get fancy with the cutting if you don't want to -- just fit it on there.
Now, you're done. You can get fancy and use a router to cut handles into the sides, or attach sturdy handles to the sides to give you something else to hold on to. I haven't done that with mine, so either way will work.
How to Use Your Compost Screen
To use your handy dandy new compost screen, just put a shovelful or three of compost in it, then either shake it to sift it into a container or onto a tarp or use your hands to push the compost around. The nice, small stuff will fall into your chosen container, and the big pieces will stay in the screen. Put those back into your compost pile to continue breaking down.
You can use your sifted compost right away, but you can also set it aside to continue breaking down if you want.
So, there you have it: an easy project to help you get finely sifted compost to add to potting mixes or garden beds!