Keyholes, Raised Beds and Maximising Gardening Space – 3 Hyper Efficient Garden Layouts

Ally and I have decided that raised beds are the way to go for our garden this year.

With only a limited amount of yard space our thoughts turned to how best to maximise the growing space.

I started with Mel Bartholomew’s 4’x4′ square garden, a size determined mostly by the reach of an average gardener.

But these beds require a pathway around them of anything from 2 – 4 feet for access. It is a pretty extravagant requirement, that can be reduced somewhat by making 4′ x 8′ beds or even 4′ x 12′.

A great idea to reduce these paths is what keyhole gardens (and American suburbs) do: incorporate a cul de sac into the scheme of things.

Theoretically, what would be the most efficient garden layout? I started playing around with permutations based on the following premises:

  • degree of success determined by the highest grow space to path ratio
  • each part of the grow space must not be further than 2 feet from a path
  • walking paths can be 2 feet wide, but major paths (for wheelbarrows etc) should be 3 feet
  • a garden fence to enclose the area

We start with two 4′ x 8′ beds with paths around them, and find they have an efficiency of 0.4.

Normal raised beds, 0.4 efficiency

Normal raised beds, 0.4 efficiency

Now we adopt keyhole garden style cul de sacs and push planting areas right next to the fence (represented by the edge of the garden), and find that we improve things to 0.7, thats almost twice the planting area in the same enclosure!

180 sq ft, 0.7 efficiency

180 sq ft, 0.7 efficiency

What if a bigger garden is needed? The following works in a 418 sq ft space…

418 sq ft, 0.7 efficiency

418 sq ft, 0.7 efficiency

Bigger still, a 1880 sq ft area. The efficiency drops but only by a little. But since the value is rounded to the nearest decimal place, it seems like a bigger jump than it is.

Hyper Efficient Raised Beds - 1880 sq ft

1880 sq ft, 0.6 efficiency

The following is a visualisation of what the garden would look like. I chamfered the corners of the wheelbarrow routes for easier turning, but that didn’t seem to make much of a dent in the overall efficiency.

Hyper Efficient Raised Beds - Visualisation

Of course, this was just a theoretical exercise, and I don’t foresee us adopting these designs due to the level of work involved to establish the whole thing. I imagine, though, that the beds can be just raised mounds for simplicity or edged with stones and brick.

Update: Google sketchup model is available for download here.

11 thoughts on “Keyholes, Raised Beds and Maximising Gardening Space – 3 Hyper Efficient Garden Layouts

  1. Hi, What program did you use to make the garden layouts?? I am working on a garden for my church and the garden plans would really be helpful.


  2. Hello,

    I’m planning on building something similar to the 180 sq ft design but in a 15 by 15 foot area.

    For the smaller joins between the 2″, 3″ and 5″ cedar planks (2 boards high, 5 inches each, 1 inch thick), how would you propose joining them?

    Decking screws to 4×4 wood posts inside the garden? 2×2 posts? post buried or not? metal brackets?

    Thoughts are welcome.

    Thanks –

  3. I have been looking at Pinterest for years now and have managed gardens for orphanage, animal shelter (permaculture) and organic commercial garden – to this date I have not found a better key hole layout. Cheers.

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