You don’t have to live in the desert to benefit from a drought-tolerant composting garden. Constructing a “Keyhole Garden” is a great way to bring a creative, sustainable garden into your life, no matter where you live.
A keyhole garden is, essentially, another type of raised-bed planter. It is especially designed to work well in places that have poor soil and bad weather, namely scorching heat and elusive rainfall. The method was “developed by a humanitarian aid organization in southern Africa, where resources are scarce and the climate unforgiving” (texascooppower.com).
With this year shaping up to be one of the worst on record for rainfall here in Central California, I’ve been taking advantage of my winter gardening “down time” to look into gardening methods that will help me conserve water and still be able to raise bountiful crops, this summer. The keyhole garden looks very promising for helping me to do just that.
Take a look at how I constructed this drought-hardy garden…
First, I measured a 6-foot diameter circle to define the inside wall of my garden, and constructed the exterior wall using cut up timbers from dead trees that we had lying around the property. I also cut out a small notch in the circle so that I can access the wire basket that I am going to place in the center. (One of the principles of permaculture and sustainable agriculture is that you make use of available, recycled materials that you have on hand, rather than purchasing items from an outside source. If you don’t have access to timbers, you could use rocks, metal, bricks, or any other material that can support the weight of wet soil). By the way, keyhole gardens do not have to be round. Here is an example of a 10′ x 10′ keyhole garden that I found on the web. It even comes with a planting guide! Next, I created a one-foot diameter tube out of chicken wire that is going to be filled with compostable material, like kitchen scraps, that will be placed in the middle of the garden and provide it with moisture and nutrients. The garden will also be watered from this juncture. Watering from the middle of the garden is supposed to force the plants to send their roots down deep and over to the tube, conserving water in the process. Following that, since we have so many problems with gophers around here, I lined the entire bed with chicken wire… Then, I lined the bed with pieces of cardboard. These will decompose as the garden matures, helping to nourish the soil and bring in lots of beneficial worms and insects. I also set the wire tube in place at this point… Then, I followed this with a thick layer of dead leaves, which are abounding around our property at this time of year. (When I make my next keyhole garden, I will lay down a “green mulch” layer first, though, following the lasagna garden method of alternating green and brown layers. Green layers consist of things like herbaceous weeds, grass clippings, and animal manure; brown layers consist of things like dead leaves, straw hay, wood chips, and newspaper)… I thoroughly watered the cardboard and leaves, and then I added a layer of hummus (a mix of compostable materials that has not yet reached the finished compost stage) on top… Finally, I added a layer of top soil (taken from gopher mounds around the property, which are actually a great source of top soil because the dirt is really clean and typically weed seed-free, since it’s coming up from a couple of feet underground – who knew those guys could be so useful???)