How to store worm castings for the long-term and keep the biology alive.
Have you ever been buried under a pile of worm castings? I mean a pile of castings so big… that you can’t use them right away?
I’ve been busy with my Worm Castings Screen Harvester and I’ve got a pile like that right here in front of me.
How To Store Worm Castings For The Long-term
We are going to talk today about how to store worm castings for the long-term. A complete worm castings storage solution.
I am going to take a common cat litter bucket, modify it slightly, and turn it into a long-term castings storage solution.
Before we do that, let’s talk a little bit about worm castings and what castings are.
Let’s think about what we have to consider when planning a long-term storage solution for worm castings.
Worm Castings Biology
Think about worm castings as a living biological entity.
Castings are a collection of bacteria, some fungi, probably a few beneficial nematodes, amoebas, plant growth hormones, and humic acids.
We need to keep our worm castings “alive”.
There are two things that castings need to survive. They are moisture and air.
How To Store Worm Castings Solutions
So, any castings storage solution we consider has to maintain the moisture and allow air for the bacteria to breathe.
Keeping this in mind…what are our choices?
1) Put in a bucket, tray, or tote: Cover with wet newspaper or burlap.
This does work but the castings will dry out quickly.
You will need to add moisture at regular intervals.
Do not recommend for more than a month or two.
2) Put in a breathable sandbag: This allows for good airflow but dries out quickly.
Not easy to moisten castings without removing them from the bag.
Do not recommend for long-term storage. A month or two max.
3) Use a plastic bucket with a tight-sealing lid and modify to limit air-flow:
I use a common cat litter bucket that comes with the lid. Modify it so there is some air supply.
Put moist castings in it, cover with wet newspaper, and put the lid back on.
This will keep your castings moist and aerobic for over a year. You should check the moisture every six months.
Common Cat Litter Bucket Solution
This is how we store our worm castings at Iowa Worm Composting. We start with a common cat litter bucket.
This one’s a Member’s Mark so I’m assuming it came from Sam’s Club.
These cat litter buckets are all pretty similar because they are constructed basically the same.
This will apply to most plastic buckets that have a tight-fitting lid.
So, a regular 5-gallon bucket that has a tight lid, would also be a good option.
We use cat litter buckets because we have them. You should use what YOU have.
Let’s Drill Some Holes in the Castings Storage Bucket
We are going to modify the plastic bucket by drilling some small holes. These holes will provide an air supply to the inside of the bucket.
We use small holes because we want to limit the amount of air.
This will keep the biological life of the castings intact while not letting too much moisture escape.
What we’re going to do is use a drill. I have about 1/8 inch drill bit here. The exact size is not that important.
Worm Castings Storage Bucket Drilled Holes
We’re going to drill two holes in each corner so there will be a total of 8 holes in the upper-sides of the bucket.
We want to drill it as high as possible on the side of the bucket because we don’t want the castings to come up over top of the holes.
We are going to drill some holes but this is not fancy… you don’t need to measure or anything.
After we drill the 8 holes, we will have a long-term worm castings storage solution.
Worm Castings Storage Bucket with Holes (Inside View)
I actually sell castings in these buckets. All I do is pull the cat litter labels off and put my own label on.
My label for the worm castings has the directions for use.
Also, I sell most of my worm castings, so I always measure how many worm castings are put in the bucket. If you are storing castings for your own use…this is probably unnecessary.
Just be sure that the top of the worm castings stays below the holes you have drilled. Do NOT pack them in.
We want to allow for air flow so scoop the worm castings in and let them settle on their own.
I measure in about 3 gallons of worm castings in a cat litter bucket. This is about the perfect amount.
The top of the castings are about an inch below the drilled holes.
Cover the castings with a section of a WET newspaper.
A four-sheet thickness is about right because we need to allow for air flow.
Be sure that the newspaper is BELOW the holes you have drilled.
Put the lid on the bucket and seal it up. You are almost done.
The last thing is to write the date on the bucket. I write the date on the side of the bucket.
The reason for this is for vertical stacking. I can stack the buckets up and still see the date.
This is the same reason that the holes are drilled on the side of the bucket.
You could drill the holes in the lid but you would not be able to stack because this would cut off the air supply.
How To Store Worm Castings Video
This is a Youtube video that we recently made. This shows us building the worm castings storage bucket.
The video is good to watch because the instructions become more clear.
Checking The Moisture of Your Worm Castings
You should check the moisture of your worm castings every six months at least. This is often enough for our operation.
However, your climate may be different. So, starting out…check more frequently until you know your own unique time table.
Check your worm castings and if they are getting too dry, you can just add moisture to them.
The best way to add moisture is to dump the contents of the bucket into a large tray or tote.
Add water and mix just like you would do to worm bedding. Make them moist but not muddy.
When you are finished.. put them back in the bucket and cover with wet newspaper. Seal it back up.
Use Unchlorinated Water For Your Worm Castings
Let’s talk about water for a minute. You do NOT want to add chlorinated water to worm castings.
Chlorine kills bacteria and your castings are full of bacteria.
If you have a chlorinated water supply… fill a bucket and let it sit for at least 24 hours.
The chlorine will gas-off and the water is then okay to use. This also applies to water being added to your worm bins.
How To Store Worm Castings Conclusion
In conclusion, this was a pretty simple fix to a common problem. We drill a few holes in a common cat litter bucket and Voila! We have an easy, cheap solution for long-term worm castings storage.