Interest in wormeries is increasing and different designs to house composting worms are available to buy. Most of these worm bins are made of plastic due to its light weight, and it’s resistance to moisture and rot. But wooden wormery can work great as well.
In fact, wood offers a couple of advantages plastic can’t provide: it lends itself better to DIY projects, can be easily customised to size requirements, is renewable and provides a more natural look. Also, wood can regulate moisture better and allows a higher degree of breathability, so addresses the problem of condensation and lack of air flow which is common with plastic worm bins.
Composting worms live on decaying plant based material and leave behind worm casts. These worm casts are incredibly rich in microbial life and nutrients (depending what they feed on). Worm compost also holds water very well. These properties make worm casts a valuable soil amendment for potted plants and in the garden so you don’t have to buy fertiliser.
Here we look at the various designs of wooden wormeries. Some are available to buy. Others are perfect for wood-working enthusiasts.
Wooden Wormeries for Sale in the UK
Wormeries for sale tend to be stackable designs. Both, fully assembled and flat packs are available to buy online in the UK.
Also, have a look locally. There are often woodworkers around who might be able and willing to build you your bespoke wormery.
How to Make Your Own Wood Wormery
What Kind of Wood is Good for Wormeries?
It’s worth taking some time to make sure you choose the right material to avoid problems later on. There are three main concerns that should be taken into consideration when choosing wood for a wormery.
- Design and where is the wormery going to be – indoors or outdoors
Durability comes down to how resistant the wood is against moisture. If you are envisioning a beautiful wormery to last years it will have to be made out of naturally rot resistant wood like redwood or cedar or other dense types of wood. You could protect the outside with an eco-friendly varnish but painting the inside would defeat the purpose of using wood for its breathability and ability to regulate moisture.
In general, untreated wood is a good choice. Coniferous woods like pine or fir will last a few years untreated before it starts to break down.
If you are after a budget friendly solution, pallet wood is a good material for a first outdoor wormery. It’s usually easily available and just waiting to be upcycled. Or, buy some construction grade wood which is cheaper than finished lumber and perfectly adequate for a fully functional worm bin.
What about pressure treated wood and lumber?
The general consensus is to avoid any pressure treated wood for a variety of reasons. A thorough read or even just a glance over this article about the safety of pressure treated wood should be sufficient to cause you to stay away from it.
Pressure treated wood is also NOT recommended for raised beds as the waterproofing chemicals may leach into the compost. Unfortunately, we couldn’t find any recent studies about chemicals leaching into soil, so can’t back this up but recommend to err on the side of caution.
However, there is some pressure treated wood that does not rely on heavy metals – so it’s worth doing your research.
Plywood for Wooden Wormeries
Exterior grade plywood is a good choice as it delays rot. Plywood is a good choice for larger wormeries including simple box type bins and flowthrough wormeries. See below for design ideas and plans.
Wooden Worm Bin Designs
Composting worms are fairly easy about their environment. They need it dark and damp, can endure temperatures between 0-30 degrees but like it most between 18 – 25. They also need food in the shape of decaying plant matter: kitchen scraps are perfect.
A well balanced wormery provides enough air in the area to keep things aerobic (oxygenated). Too little oxygen will cause anaerobic speak smelly conditions. The most common cause for this is too much water in the system.
All of this can be accomplished with a simple container if conditions are monitored carefully.
Over time, people have developed different designs to use the worms’ natural behaviour to make life easier for themselves, in particular harvesting the worm casts.
Wooden Worm Box Composter for Outside
Principle: The simplest worm bin is an enclosure with an open bottom and cover on top. The structure sits sits on the ground. There may be a perforated bottom to keep pests out but let excess liquid drain out freely.
Starter bedding material like manure, dead leaves or even wet, brown corrugated cardboard are provided to help worms settle in.
Food is added to the top. Worms make their way through the food and convert it into worm castings. The top is covered with some breathable organic material to keep light out and moisture in. Brown cardboard is also suitable as it also degenerates and gets eaten by worms over time.
Advantage: Easy to build and set up, provided with a starter bedding material to settle them in. Food is added to the top.
Disadvantage: Harvesting worm castings can be a bit involved. It means taking the top layer where most of the worms still feed and process food, of and scoop out the lower finished worm compost. Then put the worms and rotting plant matter back in for the next round.
This might not be such a big deal if done only once a year and in fact you can leave the worm compost in the bin almost eternally and could just add more food to the top and it will surprise you how much it shrinks through biodegeneration.
It does mean however, if you do want to harvest the worm castings you need to plan for that option. Large wormeries should have a hatch or removable side panels for this purpose.
Smaller worm bins can just be scooped out from the top.
Horizontal Migration Worm Bin
Principle: One box is separated into two or three compartments side by side with some holes in the in-between wall for worms to be able to creep through. You start feeding the first box and when that’s full start up the box next to it.
The worms will migrate away from digested worm castings to greener pastures i.e. the next box leaving behind nice worm compost easy to lift out of the first compartment.
Advantage: Easy design and easy to monitor
Disadvantage: requires a larger area – so not ideal if you have only limited space at your disposal.
Wooden Stackable Wormery
Stackable or tiered worm bins are one of the easiest to use systems for households rivalled only by a continuous flow through system.
Principle: The idea is to start the wormery off in the lowest tray or box and when full add another tray on top and so on. Worm compost needs at least 3 months to be digested – that’s under warm conditions where plants decay more quickly and provided there is a large number of worms at work. A normal time frame is 4 – 6 months.
A beehive wormery is a stackable system where the side walls of each layer are at an angle so they slide into each other.
Once the worms have eaten all the material in the lowest tray they will move upwards where there is more new food. Sometimes, especially with a wormery full of worms it seems the worms don’t get the memo and there are still plenty in the lowest level. However, you can still take that box and just separate the worms from their castings.
Advantage: Stackable wormeries have a low footprint and can usually be sited somewhere in the smallest of places. They are easier to monitor and worm castings much easier to harvest compared to one box systems.
Disadvantages:There is a limit to the size that is still manageable. You want to make sure that the wooden boxes when full of very moist vermicompost are still easy to lift and handle.
Wooden Continuous Flow Through Worm Bin
The pinnacle of hands off, you could say laziest system. And there is nothing wrong with that.
Principle: Food goes in on top, get finished worm compost from bottom. Worms will migrate towards the top where they find fresh food
Advantage: It’s the most hands off design as both input and output are easy to do. Worm castings can stay and improve inside the bin until needed.
Disadvantage: It can be a little trickier to build.
DIY Wooden Worm Bin Plans
Excellent wood working plans for flow through bins of different sizes.
Whichever design you go for, DIY or bought, just remember the best wormery is the one that gets used. So, pick a design and get started with worm composting to take care of your kitchen scraps sooner rather than later. The planet and plants will thank you.