Worm havens can really benefit your garden.
The Summer heat is punishing to all of us and worms can suffer as much as we do. Those that live in worm farms can be nurtured by a kind worm farmer. Those that live in the wilds of the open garden do it tougher. We can help these hard workers make it through the heat.
Compost worms live in the top 15 cm of the soil where the most oxygen and organic material is. Earthworms can go deeper to escape the heat and maintain moisture but compost worms must stay near the surface, and are more susceptible to the drying effects of Summer. Worm havens are a great compromise that attracts and nurtures worms from all depths.
Regular watering of your garden and adding compost and mulching can help worms in the soil a lot but we make little havens throughout the garden where the worms can congregate and live their wormy lives in peace while the heat rages above. The worm havens can also act as a breeding area where you can top up your worm farms from if populations dip.
We have 3 ‘worm havens’ around the garden. There used to be 4 but we planted in the space where one was. They are nothing flashy, just some 10 litre plastic buckets with a number of holes drilled in the base and sides. I originally used 20 litre buckets but found that 10 litres is a size that saves considerable labour both in the digging and the maintenance. They are buried in the ground with just the tops showing. The lids are kept on except when they are being cleaned out or topped up.
The worm havens are kept topped up with organic material, just like worm farms. That’s really what they are, just in-ground worm farms but with these, the worms come and go as they please. We don’t need to worry about the leachate, that just drains away if there’s any. We can also use them for disposing of the occasional dog poo and because they’re not touched for long periods, you can use them for meat as well.
The worm havens produce worm castings, just as do worm farms but because the moisture is kept constant by the environment, there’s no worry about flooding, compaction or lack of oxygen. Because we add dog poo to them, we only distribute the castings onto the perennial garden and not on our leafy greens or to make worm castings tea. There’s plenty of ‘clean’ castings from the other worm farms for tea making and adding to the bioponics.
The buckets need emptying occasionally. The top 5 or so centimetres, where the worms congregate is gently removed and the castings lower down removed and distributable around plants. The trick that I’ve found is to never empty out all the castings from the buckets but to leave a few centimetres of it in the bottom to encourage the worms in the soil back inside. The top layer with the worms is added back in, then food scraps added, just like in a normal farm.
Another difference between these havens and worm farms is the frequency and amount of feeding. I only feed one bin every month (and sometimes I forget that!) then cycle through the others over the next weeks. The havens aren’t used as production houses but as a safe bolt hole for compost worm earthworms and other soil biota in the hot weather. The amount of food I put in is also different to the amount I put into regular worm farms. I load the bucket up with heaps if scraps whenever I do feed it. Then forget about it for ages. You don’t need to be as fussy with worm havens as you do the farms. If the worms haven’t enough food or their population gets too large, they just move out into the soil for a while. I like to encourage them out into the garden when conditions aren’t extreme, so regularly skip feeding a haven in the nice weather.
In-ground worm havens let the worms come and go at their own pace, they attract both composting worms and earthworms as well as a wealth of other soil critters. They tend to be relatively pest free as many of our garden pests are surface dwellers – they don’t like the subterranean nature of the wom haven and the tightly sealing lid plus a covering of mulch and soil keep most unwanted critters out.
They’re not as ‘efficient’ as above ground worm farms when it comes to making castings for rapid turnover but they have a simple elegance and efficiency of their own. They are a hands off way to add nutrition and life to your soil and can add great resilience to any garden. They can be used as a breeding area for additional worms for your farms and you will know that the worms are as healthy as they can be, having lived full, wormy lives in your garden.