I feel like I’ve been living under a rock sometimes, I tell ya! I’ve written about all sorts of different “vermigardening” methods here on the blog.
Vermicomposting Trenches
Deep Mulch Vermigardening
Vermi-Lasagna Gardening
Hay Bale Vermigardening
Vermicomposting Planters
Worm Towers (and Variations)
Yet somehow the “Keyhole Garden” concept has remained off of my radar screen all these years…at least until RWC follower/customer Liane M recently clued me in, that is!
We had been having an interesting exchange about Liane’s huge outdoor horse manure heap (in TX) – yours truly living vicariously through her plans to stock it with Red Worms – when she happened to mention (and included some pictures of) a “Keyhole Garden” project from a few years back.
It became very clear, very quickly that this was an approach literally meant for composting worms! (Whether it was on the mind of the original creator of the method, or not! lol).
One of the limitations of integrating composting systems into garden beds tends to be the challenge of being able to access the composting zone (for new waste deposits) throughout the growing season. Even with something like a vermicomposting trench (with a path running along side it) can get a bit inaccessible once a jungle of healthy crop plants like squash or tomatoes starts to really take off.
With the keyhole approach, you literally design the bed so that it has a permanent little path in to where the waste materials get deposited.
The walls of this type of garden can be built up in various ways. Although, not a permanent solution, I really like Liane’s straw bale walls, and suspect these would offer a lot of protection during the heat of summer.
Here is a video (created by someone else) providing a decent little overview of this approach, and showing some more permanent (and very nice looking) options.
I would love to know if others have tried Keyhole Gardening (with worms or otherwise) – and if so, what you thought about it!
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Looks kinda fun. This summer I am thinking of enlisting the muscles of my 17-year-old grandson to tear apart a raised bed made of those wedge-shaped blocks. The existing 4′ x 20′ bed used to be in full sun and planted with sun-loving perennials when we moved here 10 years ago, with a young weeping cherry at the east end. Then, evidently thanks to a bird depositing a seed, a nice redbud appeared at the west end the following spring. Redbuds grow fast – and the weeping cherry is no slouch either, so now the bed is in full shade. But the big issue is the #%*@#! bishop’s weed that piggy-backed in on a plant I added to the bed from our previous house when we moved here. I was not consistently diligent enough in my efforts to remove it and has now taken over most of the bed, choking out everything else. My solution at this point is simply to start over by tearing down that raised area (3 courses high). The bed in the video may be just the perfect way to re-use the blocks! Won’t use it for my wormlings, though – not in central Ohio!
One thing that stuck me about the materials being added to the bed was seeing the bucketful of citrus rinds. I’ll use those in my outdoor compost bins (I have 2 “Earth Machines”) – although never in that quantity! – along with onions, bread, potato peelings and other things I have found from experience to be unsuitable for my worm bins. But that many citrus at a time seems too much and will take a very long time to decompose IMO.
Yes, I have a keyhole garden. Last spring I added red wigglers to the center basket which is the compost bin. The worms did well…but a few weeks later I found Black soldier flies in the garden, and their big fat gray larvae swarming the compost bin. I cannot tell if the reforms survived. Do they COMPETE? Do the BSF larvae do better in our 90 degree (or higher) Texas summer weather?
Very interesting, Patti! Black soldier fly larvae tend to do really well in outdoor composting systems in warmer locations – and yes they can certainly dominate a system where worms are present, since conditions are often much more favorable for them. My thinking is that this sort of system could actually help the worms a lot since they could likely continue to hang out further down where it is cooler etc – and they could further refine the leavings of the larval activity, providing plants with an even higher quality “fertilizer”. Worms should definitely have access to zones where temps are below 90 if at all possible.
I have tried it before, but was deterred by opportunistic rats that were attracted to the concentrated food source. I recommend using a stiff hardware cloth for the center. Cover the top with a stepping paver to avoid vermin access. Insects and worms can still move around.
This is the main reason why I started vermicomposting in the garage! I plan to fill huge tall garden beds with something similar to work needing mixture with keyhole garden principles (like using cardboard and shredded paper). Not sure if I’ll add red worms or keep them in the 2 UWBs I bought from you 😉
Good to know that the worms “might” have survived. It was just a fun experiment. Once the plants in this garden get big, and they did, I couldn’t see what was happening in the composting basket anyway.
I am sure some hot competing occurred at least once during the summer when I put a lot of canteloupe rinds in there, and it did start to smell like garbage. The fire ants that were ALSO living in the compost area migrated out like mad.
Can worms live “with” fire ants? Those worms definitely took a beating.
The activity of the larvae can actually serve to increase microbial heating and just generally make things less worm-friendly. One way to help some is to make sure lots of bedding materials (and living materials if you have em) are getting added as well. The larvae like it rich, wet and foul smelling – and won’t be as interested in the environment if it is more catered towards the worms. Very interesting re: the fire ants! They can be another “pain” in warmer outdoor locations – often on the drier side of things (if a system gets too dry they can thrive).
I am happy to see that a few others have experimented with this. I have been checking on the worms that I introduced to the keyhole garden and they seem to be thriving. Of course, our Texas temps haven’t really gotten high yet, but I am hoping that the worms will escape to lower and cooler parts of the garden once temps do rise.