The square foot gardening method was invented by Mel Bartholomew, who wrote the book Square Foot Gardening in 1981. It is a space-saving, high-yield alternative to planting crops in rows.
Square foot gardening uses raised beds, commonly made of untreated cedar, pine or, fir. The beds have a maximum width of four feet to give easy access to the center, and typically a length of four or eight feet. The depth ranges from six inches to one foot—the deeper the better.
The square foot bed is divided into a permanent, flat grid of one-foot squares. Each square can be dedicated to a different crop. The number of seeds or seedlings that you can plant in each square is determined by the mature plant size and the required spacing.
The Pros of Square Foot Gardening
Square foot gardening is promoted as a highly productive, space-saving way of gardening. It requires 80% less space than planting in traditional rows, and no space is being wasted by paths.
The beds provide easy access, also for gardeners with limited mobility.
It does not matter if you don’t have good soil in your yard, as the bed is filled with fresh, fertile growing medium. The recommended soilless mix consists of equal parts compost, peat moss, and vermiculite.
Unlike starting a garden in your back yard that might require you to remove sod or turf, a raised bed for square foot gardening is quick and easy to set up on any surface, as long as the bed provides enough depth for root growth, ideally one foot or more.
Beds for square foot gardening can be placed around your yard in different locations—any spot that provides at least six to eight hours of direct sunlight. without shading from trees, shrubs, buildings, or fences.
The bed is filled with a soilless mix, which means that there will be no weeds in the soil, at least during the first year, and no tilling is needed. The frame serves are a barrier against weeds encroaching from the outside.
Because you don’t ever step on the soil, no soil compression occurs.
The clear division of the beds makes succession planting and annual crop rotation easy to manage. After one crop is harvested and the square is empty, you plant a new crop in its place.
A square foot garden is easier to protect than a regular garden simply because it’s a smaller space to cover: with a removable dome made of chicken wire or fine screen over it against critters, birds, and harmful insects; with a shade cloth to protect tender crops such as lettuce from the scorching summer sun; and with a clear plastic cover for frost protection.
The Cons of Square Foot Gardening
As great and easy as it sounds, there are also several disadvantages to square foot gardening:
The installation cost for raised beds is high. To this you need to add the cost for the soilless mix, which needs to be refreshed every growing season.
A densely planted garden lacks air circulation, which is an ideal breeding ground for all sorts of plant diseases. This is aggravated by humid weather and frequent rainfall. And if a disease hits, it will spread fast due to the close proximity of the plants.
An overcrowded garden bed also leads to light issues. Crops overshadowed by others will grow poorly, and fruit won’t ripen.
Like all raised beds, square foot gardens need frequent watering. To prevent overwatering, soaker hoses and drip watering are recommended, which can become another cost factor.
There is no guarantee that weed seeds won’t blow into your raised garden bed. And once established, weeds can be worse than in a regular garden bed. Because the space is so small, when you pull weeds, you might accidentally uproot your seedlings at the same time. Therefore you should pull weeds as soon as they emerge.
Tall crops and vines such as cucumbers, melons, summer squash, and pole beans can be grown vertically on a sturdy trellis but keep in mind that they will shade other crops. Also, strong winds or a rainstorm can topple over even the sturdiest trellis.
Spacing Chart for Square Foot Gardening
Here is a calculator for square foot gardening:
| Spacing according to seed package or planting instructions | Plants per square foot | Garden crops |
| 12 inches apart | 1 | Broccoli |
| Kale | ||
| Collard greens | ||
| Cabbage | ||
| Potatoes | ||
| Sweet potatoes | ||
| Peppers, hot peppers | ||
| Tomatoes (determinate) | ||
| Eggplant | ||
| Cucumbers | ||
| Summer & winter squash | ||
| Corn | ||
| Six inches apart | 4 | Edamame beans |
| Green beans | ||
| Peas | ||
| Swiss chard | ||
| Annual herbs (cilantro, basil, dill) | ||
| Lettuce | ||
| Four inches apart | 9 | Garlic |
| Large onions | ||
| Spinach | ||
| Beets | ||
| Turnips | ||
| Two inches apart | 16 | Scallions |
| Radishes | ||
| Carrots | ||
| Mesclun |
Many crops are sown denser and then thinned out as they grow. The numbers given above are for the final spacing.
Keep in mind that many culinary herbs such as rosemary, chives, oregano, and sage are perennials that will occupy that space over an indefinite number of growing seasons.
Large tall crops, especially corn and tomatoes, will cast considerable shade on other plants. To prevent this, it usually works best if an entire square foot bed is used exclusively for the same crop.
For the large crops, choose compact or dwarf vegetable varieties specially that have been specially bred for container growing, such as Pixie tomatoes, and bush-type cucumbers, summer squash, and zucchini.
Is Square Foot Gardening Right for You?
Square foot gardening allows you to maximize garden space and create a small and—if you keep after it—neat kitchen garden.
For first-time gardeners, square foot gardening is a good way to start small and get some experience before thinking bigger. It's also a great way to garden with kids and introduce them to growing your own food.
Be realistic as to which crops you can successfully grow with square foot gardening given the pros and cons listed above.