When space in the garden is tight, we look for every technique to make the most of it. And one of our favorites for vegetable gardening is Square Foot Gardening.
Developed by Mel Bartholomew, Square Foot Gardening maximizes food yields in small gardens by using successive planting techniques and intensive spacing. While originally developed strictly for use with raised beds, we’ve found these techniques work well when gardening directly in the ground, too.
Divide It Up
Square foot gardens are divided into one-foot-square blocks, with the block marked out by a grid. For example, a 3′ x 3′ bed is divided into 9 1-foot squares.
Each of these blocks is planted with different vegetable, herb, or flower. As a result, square foot gardens are chock full of diversity, which increases their resistance to pests and diseases. And they’re already so full of plants that weeds have very little chance of gaining a foothold.
Plant Based on Mature Plant Sizes
In a traditional row garden, we plant seeds thickly, assuming that not all will germinate. We then have to go back and thin, or pull out, seedlings to make sure that the remaining ones have room to develop.
In square foot gardening, we plant based on the mature spacing, saving seeds in the process. Here’s how:
- The seed packet says to sow lettuce 1″ apart, then thin to 6″ apart.
- Instead, plant the lettuce seeds 6” apart.
- In a 1′ x 1′ square, you can plant 4 seeds 6″ apart.
- Divide the square into quarters and plant one seed in each.
This spacing technique works for plants of all sizes. If the “thinned” spacing is:
- 1′ between plants, plant 1 per square.
- 6″ between plants, plant 4 per square.
- 4″ between plants, plant 9 per square.
- 3″ between plants, plant 16 per square.
Bigger plants are either trained up trellises or planted in an 18″ x 18″ square.
Check out this Purdue University Cooperative Extension publication for more.
Keep the Harvest Coming
By managing the garden with successive plantings, you can get enough salad crops for two adults for a whole season out of one 4′ x 4′ bed.
As soon as you harvest one crop, add some compost to that square, then plant it with a different crop. And because you plant something different each time—lettuce crops might be followed by beans, which might be followed by carrots—crop rotation strategies are pretty much built in.
To succeed at square foot gardening, you need rich, well-amended soil. If you’re using a raised bed, we like a combination of one-half topsoil and one-half compost.
If you’re instead working straight in the ground, you must work to keep your soil fluffy. Establish paths and stay on them so you don’t compact soil in the beds. Regularly amend your soil with compost and manure.
In both raised and in-ground beds, take advantage of cover cropping when you’re not growing food crops.