How To Make Your Own Compost Sifter
Composting at home is not only fun and easy, but it’s one of the best things you can do at home to lead a more sustainable lifestyle. Not only is it extremely important that we divert food scraps from the landfill, it’s rewarding to convert them into nutrient-rich compost that can be used to amend the soil and feed your plants.
If you’ve ever worked with your own compost, you might’ve noticed that not everything breaks down at the same rate. Not only does this result in unevenly sized particles, but unfinished compost can actually lock up nitrogen in the soil, making it unavailable to plants.
This is where a compost sifter comes in handy: it breaks up the compost into a fine mixture and separates out any larger chunks that need more time to break down.
Fortunately, a compost sifter is easy and inexpensive to make with just a few tools and materials, most of which you probably already have laying around. In this article, we’ll walk you through the process and tell you everything you need to know about compost sifters so you can make your own with confidence.
Why use a compost sifter?
If you’ve ever harvested your own compost, you’ve probably noticed clumps of unfinished material. Not everything breaks down at the same rate, so while most of your scraps may have turned into compost after a few months, there could still be pits or pieces of wood that could use some more time to cook.
Although there’s little harm in adding some chunks along with finished compost to the garden (especially as mulch), there are certain benefits to screening your compost first. Not only does it break up these clumps, it also separates unfinished material from finished compost. These larger bits of material can then be returned to the compost pile to continue breaking down instead of locking up nitrogen in the soil.
Sifting your own compost is especially important when using it as part of a seed starting mix. Seeds, especially small ones, would have a difficult time sprouting around or through a piece of wood, for example. To avoid interfering with germination, make sure that your compost has been sifted through a ¼” or even ⅛” screen.
A compost sifter is an essential tool for the home gardener, no matter what kind of composting you do. As you might imagine, you can’t just use the sieve in your kitchen—these are too small, too lightweight, and too fine to sift compost with. You can buy a compost sifter online, but the easiest and most cost-effective method is to build your own (DIY).
What kind of compost sifter do I need?
When choosing or making a compost sifter, there are a few things to consider, namely: size and durability. Let’s take a look at both of these factors:
Size
There’s no one size fits all when it comes to compost sifters. Choosing a size not only depends on the amount of compost you plan to be screening, but also where you’ll be screening it into.
My favorite way to sift compost is over a wheelbarrow. You simply rest the sifter on the sides of the wheelbarrow and push it back and forth to let the compost fall through. You can also work your hands through the compost as a slightly less strenuous option.
When sifting with the aid of a wheelbarrow, it’s important that your compost sifter fits across the wheelbarrow width-wise. That is, it should be at least as wide as the wheelbarrow itself. A typical wheelbarrow compost sifter measures about 2x3 feet.
If you’re only planning on screening a small amount of compost at a time (such as black gold from a 10 gallon worm bin), you can get away with a smaller compost sifter, or even a handheld one. Keep in mind, the smaller the sifter, the less compost you can screen at a time.
Durability
Unlike a kitchen strainer, which is built to hold things like powdered sugar or fruits for rinsing, a compost sifter needs to be able to hold decent amounts of heavy, moist compost. This means that the materials of the sifter matter, because otherwise it’ll fall apart after just a few uses.
If you’re screening small amounts of compost at a time, you can probably get away with a manufactured plastic sifter. However, I’d recommend that the sifter is at least made of galvanized steel; plastic is more likely to break down over time.
For most homemade compost sifters, especially for wheelbarrow screening, the main material is wood. Type of wood isn’t as important, so feel free to use scrap wood to build your sifter. However, 2x4” pieces of lumber will offer the most durability.
In addition to the materials that make up the frame, there’s the question of the screen or mesh itself. When it comes to a homemade compost sifter, it’s best to use hardware cloth with ½” or ¼” mesh. Hardware cloth is made of galvanized steel and is designed for durability and resistance to rust.
How to make a compost sifter at home
Now that you’ve got an idea of what size compost sifter you want to make, it’s time to gather a few materials. You might have many of these materials laying around already, but they’re relatively inexpensive to source if not.
Here’s what you’re going to need to build your own compost sifter:
Materials for building a compost sifter
Wood or an existing frame, approximately 2x3 ft or as desired; pieces of scrap wood will work, or you can buy approximately 10 ft of 2x4” lumber
Saw
Hammer and galvanized staples
Drill and wood screws (or hammer and nails)
Measuring tape
Hardware cloth: I like ¼” mesh for screening most types of compost, but depending on your preference you could go to ½” or even 1” mesh. For very fine compost, such as vermicompost, you could even go down to ⅛” mesh.
Sheet metal snips
How to build the compost sifter in 6 easy steps
Have you gathered your materials? Are you ready to build your very own compost sifter? Luckily, it’s easy to do! Soon you’ll be sifting your compost like a pro.
Just follow these 6 simple steps to build your own compost sifter:
Determine the size of your sifter. Most hardware cloth is 2’ wide, so you may want one side of your frame to match in order to reduce the amount of cutting you’ll have to do.
Measure and cut the wood for the frame, for example two pieces 2’ long and two pieces 3’ long.
Screw or nail the pieces of wood together to form a rectangle.
Unroll the hardware cloth over the frame. Some overlap is okay. Hammer galvanized staples to secure the mesh to the wood as you go.
Mark where to cut the hardware cloth, and do so using the sheet metal snips.
Finish securing the hardware cloth in place using staples.
Optional: you can choose to add another layer of thin wood (such as 1x2”) over the hardware cloth and frame in order to further secure it. This can also be done to add extensions of the frame, if desired. For example, I’ll screw pieces of 1x2” lumber, with the top and bottom pieces being longer than the frame itself. This is particularly useful if you have wheelbarrows of varying size so that the sifter can fit on all of them no matter the size of the frame itself.
One of my first compost sifters (with chicken wire instead of hardware cloth).
How to screen compost using a compost sifter
Now that you’ve got your very own compost sifter, it’s time to put it to use. To screen compost, first make sure that it’s mostly finished. You want to look for compost that is dark and loamy, and smells like soil (it shouldn’t smell bad). It’s okay for there to be chunks of unfinished material, as those will be separated by screening.
To start sifting your compost, simply place your sifter over a wheelbarrow or other vessel such as a bin or bucket. Add a few scoops of compost, being careful not to overload the sifter. Adding too much compost at a time will make it more difficult to sift, wasting precious time and energy.
The fine compost will fall through the screen and into your container. To speed up the process, work your hands across the compost, or shake the sifter back and forth, until you’re left with bigger chunks of unfinished compost.
When harvesting worm castings, be gentle so as to avoid accidentally killing any worms. Make sure to use a ¼” or even ⅛” compost sifter so the worms and debris stay on top and you’re left with black gold only.
Simply repeat this process until you have a satisfactory amount of beautiful, screened compost in your wheelbarrow or bin. You can immediately add it to your garden, or wait a few days until you’re ready to use it.
Don’t forget to put the unfinished chunks back in your compost bin! You’ll know it’s time to harvest compost again when it’s dark in color and smells like soil.
What differences have you noticed between screened vs. unscreened compost? Have you noticed any benefits to your plants and garden by adding compost? Let us know below!
