I've Got Worms - And That's a Good Thing!

 Using Worms In Your Garden

The TEdAWORM garden bed

Our new landlord (as of two and a bit years ago) took over our lease from the old landlord, put up our rent - and then took away 96% of what area we'd had for gardens by splitting the block in half. . . (And please - this isn't a shot at the landlord, who has in fact made everything far more secure and comfortable for us in return.) We had to uplift about 25sqm of raised and in-ground garden beds out of the huge backyard and move six of them into the pocket-handkerchief-sized front courtyard garden, and that 6sqm plus about 2sqm more in between the beds became the new vegetable garden. The other 12sqm or so is our ornamental and relaxing garden. 

We loved our backyard vege garden and always had a few things growing in it for cooking, and now suddenly we were down to a quarter of the space I'd had to make it produce for us. I'm a slightly less than average gardener anyway, which doesn't help - I forget to water on the hottest day and lose a whole crop, I get too unwell to physically get on the ground and pull weeds so they compete with the plants I want, and so this time I've aimed for gardening I can manage and that will produce well for us.

I remembered ages ago reading about keyhole gardens in Lesotho Africa and decided they were ideal with their clever feeder buckets. 

Except.

We had those tiny rectangular 95x85 steel garden beds you can buy at most garden and hardware places for $20 - $40 and at 30cm tall they aren't anywhere near high enough to make a decent Lesotho garden. A real keyhole garden bed should be waist high. So instead I concentrated on the feeding bucket part of the whole thing - and realised I could use that as a starting point for a small worm feeder system for a small raised bed. A system that fed the worms in situ and so bring the worm farm to the garden, so to speak.

This is where my thinking cap hatched the Plan. The feeder section in a keyhole garden is where you drop scraps for the worms, and the worms do the job of eating it, digesting it, and then depositing it around the garden bed in the form of worm poop. It's the central part of how a keyhole bed works - not so much the shape, but the feeder.

I had two problems, the problems were the weed mat (which people say worms have no trouble squeezing through but I was dubious) and how to make a repeatable and reliable worm feeder that looked good enough to be in our living space courtyard.

We had old packing cartons and laid those over the weed mat as a further isolating layer. It breaks down really quickly in the warm moist damp climate and soil here so it would have melted into the soil by now but it did help keep everything in place while we worked.

The problem then was to feed worms, lure them up above the weed mat into the garden bed soil, and be able to close the feeder against evaporation and bright light because worms hate both of those things. There's also the old myth that worms hate vibrations but there's a highway 5m away from the beds and our worms have never heard that particular story and don't care at all even when a big B double semitrailer rig thunders past and makes our windows rattle. Long live the worms! 

Breaking Ground

First we looked at the area we had which was a newly fenced area that had a 45 degree corner for reversing out of the driveway. We made an L shape with equal sides and it took 5 garden beds. (I later added another bed on the end of the arm to the right as a cat toilet but they have other ideas and so now the beds all have to take turns...)

I later abandoned the idea of having uprights and
everything just sits on the ground and doesn't move.

The little Tinkercad sketch I made (above) was all we needed in order to break ground on the project. It was just a rough draft but we bought some big garden sleepers and made it so. Two garden beds sit in each leg, and one in the diagonal section. There's weed mat laid down all throughout. There's a space between the beds in each leg, that we stuck plastic pots in. And there are spaces, one either side of the angled bed, with more pots in.

Once the sleepers (in red) were in place we dropped weedmat all the way around, placed the raised beds in their final positions, then put packing carton cardboard over the mat in each bed. Then two cuts 100mm long and at right angles made in the centre of each bed through the cardboard and the weed mat, a sort of "X marks the spot" for the TEdAWORM Worm Feeders. Only five of the beds got feeders because the last one was meant to be a cat loo. (Yeah, some hope hey?)

Here you can see the
worm feeder placement.

 

A look straight down.

Roughly measured PVC pipe.

Okay - so you can see almost all the elements of the garden beds come together in those four photos. The sleepers forming the overall outline of the garden, the gap between a bed and the next one for pots; then a view down the food chute, and two pictures of the 100mm PVC pipes that the worm feeders are made out of.

There's some amount sticking out above the ground. In my case I used about 20-30cm stuck above the soil, then holes drilled in the pipe from just below the surface of the garden bed's soil, then a line approximately where the pipe will go through the "X" cuts in the weed mat, and then another 20-30cm below that where the food forms a lure to bring worms in. So the worms can either force their way up through the weed mat, or in through the lower holes in the pipe, and then up and out into the garden beds.

I'd never given much thought to what the worms' incentives to go upwards would be, but it turns out that they do that anyway, and the beds are (two years later) quite healthy and useable. They dislike noise and vibration, according to lore - but we live a few metres away from a highway that has trucks and machinery passing by all the time - and there are plenty of worms around. Nobody told our worms the story apparently...

True Story I Swear: I probably needn't have bothered to make any arrangements for the worms to get from the holes below to the holes above the mat. When I went to plant the first plants the ground already had worms in it. Might have been because we also shifted much of the original gardens' soil and reconditioned it then used it to fill these beds, but they were also straight up through the weed mat, they then also quickly found their way up the drain holes in the big pots, and were teeming in the pots - and we used new bagged potting mix in those so it had no worms prior to filling into the pots...

Anyway. We dug down into the ground under the Xs and pushed the PVC pipes down, then returned a few handfuls of the dirt back down the pipes to lock the bottom in place, and now after two years, they're immovably locked into the ground. I've emptied dozens of scoops of vegetable scraps into them, and to make it appealing to the worms, keep light out with end caps. 

Five 100mm PVC end caps with some plastic drawer handles make the lids to seal the feeders, and the reason I made my tubes stick up 30cm above the bed is that at that height I can reach over the wire mesh surrounds you can see in the first picture to fill the feeders, because we needed to let our cats enjoy the courtyard too, but stop them digging up our seedlings to poop there.

More recently I added reticulation circuits around the garden and the one with the lowest pressure and shortest ON time I added some thin tubing, through a hole in each cap and put a slow dripper there, which means that when the reticulation comes on, the food scraps get soaked and the moisture attracts even more worms. 

The underside of a feeder cap - you can see the
screws holding the handles and the red dripper.

Cat loo preventer. Hinged
for easy deployment.

Last three beds - the last one
was supposed to be the cat loo, is
now just another bed in rotation.

Here are three more clever/frugal things - the lattice panels were recovered from our old garden beds and resized to fit into a bed for climbing support. Then in the detail picture you can see how I hinged the front and sides of the wire mesh panels so that they can be folded and stashed flat when not needed.

And you may have picked up that there's actually a third raised bed right at the end outside the sleepers, and that's the one we put in especially as a cat loo - and of course, they don't use. So now we've actually used it as a composting bed, and grow potatoes under it and green compost plants up top, and turn that material under a bit and then use it to top up the organic content of the other five beds. The cats meanwhile get the use of each garden bed we fallow for a few months so they get to enrich everywhere... 

Last Minute Words Of Wisdom

We've had these beds since 2020 and they've been productive as anything. I drop clippings down the feeders, food scraps and composted food scraps, and sometimes even a handful of soil. The worms seem to carry most everything away, but if they ever needed clearing out a small scoop on a stick would do it, and the worm gunge brought up that way could be used on the garden beds to enrich the soil and improve water holding capacity. 

I could 3D print a suitable scoop and I might do that one day, if I do the .STL files and some new images will appear in this post.

One of the beds has become our perpetual aromatic herbs bed and as soon as they've all grown a bit taller we'll let the cat use that as a loo because the won't be able to dislodge a healthy rosemary or lavender, and the pineapple sage and curry plant are already big enough so we're just waiting - one more winter - for the others to catch up.

UPDATE in mid 2023: The pineapple sage grew HUGE, has had to be pruned back hard twice already. The cats have tried but failed to dig the aromatics out, and I keep adding mulch and soil to keep it going, also a good spray with seaweed extract every so often. The worms do a great job of feeding the plants.

(Also, 'barriers'  of short bamboo stakes can prevent the cats from digging where we don't want them to.) Anyone worried about cat poo should consider that any unfenced open garden bed would cop this anyway, and also WE HAVE WORMS and they eat poo. hehehehe. No problemo!

I've already run reticulation hoses from the taps, along the fence, and past each of the beds, there are three in all and I'm building and programming a retic controller for it to take away one of my last few chances to fail, that of letting plants dry out. By running all three circuits past each bed I can select which watering cycle out of the three is more appropriate for the plants in it, also of course the pots are all in reach of three different watering programs too, and as I'm planning a few sensors and some weather awareness in, I should be sure of keeping everything alive all year 'round.

While the lower garden beds aren't as kind to my knees and back as a proper keyhole garden setup would be, between the handy sizes of the beds and having a decent kneeler makes a lot of difference. 

Added 02/June/2022: Brief Discussion Of How It Works:

The classical Lesotho keyhole garden is built up with tin and plastic and sticks and cane and filled with trash and fillers until a foot or so (~~30cm) from waist height, then a floor is laid over that and then the actual garden soil. The garden plan from above is a circle with a wedge taken out of it. At the point of the wedge, a cylinder is partly buried, on end. Often a cheap plastic bucket with the bottom removed. 

It must be light-proof and have a lid that fits and keeps light out. Then the household food and garden trash scraps are tipped into the bucket, the lid is put on, and the garden is planted and watered well and kept watered. Any worms in the garden soil will find the food and start eating it, distributing it in the form of worm poo around the garden bed. It in fact replaces fertilisers with worm castings. 

In the plentiful sunshine of Africa, keeping the plants watered at all times is one of the keys. Worms only like damp to wet soils and will die if you stop watering, and plants need water all the time too, as otherwise they have periods of not growing, or worse, actually lack of moisture doing them damage that they'll never recoup. So the need to constantly keep water up works for both worms and plants.

In our case, the beds are ON the ground not ABOVE it, but the weed mat gives a degree of separation. The PVC pipe bridges the regions beneath the weed mat with the soil of the garden on the weed mat, and the region above ground that's used as the filler. The series of holes drilled into the sides from just below the garden soil to the region below the weed mat provides easy passages for the worms up from the ground, into the food, and into the garden bed soil.

To be honest, supposedly the worms can squeeze through holes in the weed mat but they need access to the worm food so there need to be side holes a-plenty. In our old kitchen garden when I was a kid we used to bury food scraps in the garden beds, same deal but worms hate disturbance so the feeder is a little better. That leads to the corollary, the length of PVC pipe above the ground that should all be filled with food scraps, watered very occasionally, and otherwise left alone.

Water the garden beds regularly to keep the plants and worms happy, and every few months or so, push the food down and refill the tube. It can last from a few weeks to a few months - in my case about 2 - 3 months, and would be better if I'd used 150mm PVC instead. But that starts taking away from the plantable area of the bed, so it's a balancing act. 

On the bonus side: The 'garden soil' you get from most garden centres is just mineral dirt with little organic content. For the first year I was mulching the soil with wood chips and shavings, dry grass, I planted a few crops of green manure and dug it back in, and in that process and with the worms' assistance, the soil has organic content and structure and isn't just rock hard clumps.

Don't overdo the fertilisers, I used maybe two handfuls of a pelletised all round fertiliser and a few watering cans of diluted Seasol across all five beds in the first year, and since then I haven't needed to add anything but water, scraps, and compost made in a bottomless bin quite close to the beds. (I had more scraps and didn't want to waste all of that goodness so as much of it as our worms will eat, I'd rather it went into my gardens than the local composting place where it doesn't do anything for my gardens.) 

Added 14/05/2023: The Millie Notes: 😸

(Response to a Facebook query.)

I don't actually put brown in. I figure that it isn't compost I'm making, and the worms are in the wild and so they can balance their own diets, what goes in is kitchen vegetable scraps, trimmings, scraps, and prunings from picking and managing the veges, and sometimes solarised grass runners. I don't move the feeders at all, I reckon the worms may have some kind of bush telegraph and moving the feeders would only confuse them. (No - JK, but apparently they're happier when their feed areas are undisturbed so I try not to disturb beds or open the feeders where possible.) 

The feeders are cheap enough to make, mine are about a metre of PVC each and if you don't mind bending down to fill them (and disturbing the worms more often due to having to fill them more often) you could get away with a 60cm length so you could get quite a few from a single length. I've used around 1m lengths because a) I can fill them to the top with scraps and the water dripper stops them crisping in the heat and sticking to the sides and so I can get up to 3litres of scraps in at a time, b) at my age I prefer not having to kneel or bend to fill them, and c) I sometimes have the cat screens up and they're 90cm tall so it's easier to reach over and manage the feeders. If you don't have tiny raised beds like I have and are using longer beds, I'd say put feeders in with the thought in mind that they each cover a 60cm - 80cm radius. 

I have five feeders, one in each of the original five beds (and I'll make another one for the "cat loo" when I find another metre of 90mm PVC laying around on a worksite or whatever) and the tube I had was 90mm diameter, I can fill them quite a long way so I can get between a litre and maybe up to three litres of scraps into each one at a time. (More if you use 100mm PVC, sort of in the 1.5 - 4 litre range.) I just used what I had to hand. Rather than disturb the all feeders every week, I start at one feeder and do that, collect scraps for a week or so and do the next one, etc. If they're still full when I go to start a new round, the scraps that week go to the Council organic bin because I don't have a lot of space now so I don't have compost any more. And anyway the worms dispose of a fair proportion of my scraps and trimmings/prunings. 

They're also coming up and cleaning up the cat doings, I just push those down 3 - 4cm deeper with whatever's to hand and they magically disappear. Being worms, they prefer green scraps to dry browns, also it takes longer for bark and mulch to break down. I suppose you could also half bury a 20 to 50 litre drum with holes drilled around the bottom half and just throw compost mix in there, the only problem I can see with that is that the heat would probably be quite unpleasant for worms and also that's a large lump of material to go anaerobic because once it's down you shouldn't disturb it again as it'll drive the worms away for a while. (Some disturbance doesn't seem to deter ours because we have the Bass Hwy right outside so there's disturbance 24/7. But I still like to keep their feeders as peaceful as possible.)

In the old days people would just leave some beds fallow, dig smallish deep holes all over and fill them with kitchen scraps then cover them over, and then plant on them a year later. What I'm doing is similar but without the hassle of stepping (or worse, kneeling) in your garden and absent-mindedly going squish into a 30cm deep hole full of three months ago's dinner leftovers... 

This is all not an exact science, you need to sort of balance the volume of scraps, how fast it can rot, adding the water drip to keep it cool enough for the worms to feed, and the need not to disturb the feeders too often. I think I hit a lucky sweet spot with the material I had, also the ground we're on, etc. We have really hard clay 50cm below the surface and when it rains that drives the worms upwards into the raised beds. Lastly I can foresee the need one day for a 3D printed 84cm diameter auger scoopy thing to lift out worm castings from the bottom of the tubes to make room for new scraps, and I hope we can get some drainage in the naxt year or two. 

But do experiment - give things a try. 

Conclusion:

It took myself and a friend a few days to cut the sleepers and screw them together, weed mat it, and cart in the reconditioned dirt from the old garden beds. The sleepers cost under $200AUD when we bought them but since then COVID and all the shortages associated with it have probably put the price closer to $400 - having a source of old sleepers might be wise. 

This is the beginning of the third year for the garden and the soil's still only just settling in nicely. Turning it right over really killed it. Once your beds are established only make holes where you're going to plant something or have taken something out, and let the worms look after the soil for you.

Mulch on top with light material that they can come up at night and eat and they'll carry it down and build soil for you. Add extra dirt only if you absolutely have to, organic material is preferable. 

We don't use pesticides other than a few snail pellets (and only in closed-off beds to prevent any risk to the cats) and white oil or organic sprays, and for fertiliser I use a granulated one - and that only very rarely because the worms are doing a great job recycling our food waste for us. 

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