Square foot gardening is ideal for the tidiest of gardeners. If you’re addicted to Marie Kondo’s minimalism, love hospital corners, or just plain want the most efficient garden on the block, then this type of gardening is perfect for you.
This orderly layout is an ideal way for a busy, suburban gardener to grow vegetables. The tight-knit neighborhood of plants you’ll create will crowd out weeds, and choosing companionable plants can also minimize pest problems.
It’s also ideal for the small-space gardener with homestead appetites. Square foot gardening maximizes space and minimizes effort, which is really an ideal combination, isn’t it? They’re functional, effective, and visually intriguing. But, what exactly does “square foot gardening” mean? Read on and you’ll find out.
The Square Foot Garden
In simples terms, square foot gardening is the practice of dividing your growing space into a series of 1 foot by 1 foot squares. Each section contains a different type of plant. These plants are chosen and arranged to grow well together. Tall plants, for example, grow along trellises on the north side of the block, to avoid shading smaller plants.
In square foot gardens, the plants grows close together in intensively planted units. The ideal unit is a 4 foot by 4 foot square containing 16 1’×1’ plots. Other options are possible, however. The basic 4’x4’ plot can be expanded into a 4’x8’ square, or even a 10’ x 10’ to suit your needs, and the space you have available.
Each plot is divided up into lots. 1’x1’ is the ideal—and of course, how the method got its name—but you can play with that as well. Some square foot gardeners like to create larger lots: 2’x2’ for example. This allows you to grow more plants per square, but it will change the overall look of your garden. Expanding the grid may make your garden look less like a square foot garden and more like a conventional one.
In square foot gardening, the grid layout is key to success. This type of layout allows you to space your plants properly, visualize clearly, and keep all boundaries in place.
The square foot method was first presented by engineer Mel Bartholomew in his 1981 book: Square Foot Gardening. It became widely popular, especially in small suburban yards and urban gardens.
Bartholomew has an engineer’s taste for order and efficiency. In fact, his gardening method encouraged hobby gardeners to think of the science and practicality behind their plant layouts. They were able to make use of ever inch of garden space to grow successful, sustaining gardens. No wonder it was so popular!
Square foot gardening is still inspiring gardeners all across the world. Bartholomew has since issued an updated version of his gardening classic, called All New Square Foot Gardening. Don’t be confused by the title, though! He hasn’t completely changed his system—he’s just worked out the kinks.
The new book contains more advice on mixing an ideal planting soil and working through surprises. As a result, it builds on the original concept instead of creating a whole new one.
So, How Does It Work?
All this talk about grids and measurements might seem confusing, but square foot gardening is actually pretty simple. At its most basic, this method is just like laying out a city block of houses. Let’s break it down:
Build a Square
You’ve got to start by building a 4’x4’ square box (technically, it’s just a big raised bed!). Mark out the dimensions first, then get started. You can build the square with untreated lumber (I recommend cedar), or with other materials. Concrete blocks are popular, bricks are a beautiful-but-expensive option, and vinyl is another, completely utilitarian option.
Whatever you use to build your big square, make sure you’re able to get neat, right angles out of it. The garden’s structure depends on the outer bed being truly square as it’s laid out.
After building the 4’x4’ bed, Bartholomew strongly encourages you to put down a weed mat, or a patch of landscape fabric. This will prevent weeds from coming up out of the ground beneath. You’ll be filling the bed with your own, mixed potting soil anyway, so cover up that earth.
Add Some Soil
Don’t just add any soil to your square foot garden! Bartholomew recommends a blend he calls “Mel’s Mix” for gardeners following his method.
Square foot gardens are intensely planted. With so many plants sharing a small space, it’s therefore essential to give them great, nourishing soil. Mel’s mix is light, friable, and nutrient dense. He introduced this formula in his second book: All New Square Foot Gardening.
Blend up one part each of:
- Coarse Grade Vermiculite
- Sphagnum Peat Moss (or Coconut Coir)
- Blended Organic Compost (Mel encourages you to source 5 different composts and combine them here. If your compost bin is full of a variety of materials, however, I wouldn’t worry too much about finding 4 other blends to mix with it.)
Fill the box with Mel’s mix, or your own preferred blend. If you’re building the traditional 4’x4’ box, and your raised bed is about 9” deep, you’ll need about 12 feet of soil mix to fill your bed.
After you fill the bed and rake the soil smooth, you’re ready for the exciting part!
Add The Grid!
You can make the grid easily and inexpensively with wood lath from a local home improvement store. If you have access to old venetian blinds, those would also work well. Lay out the grid on a smooth, flat surface and measure out one-foot increments.
As you measure, lay out the lengths of lath to build your grid. When you’ve got the whole grid laid out, and you’ve checked your measurements twice, tack each corner together with a short nail. Exterior trim nails are ideal for this process because they’re galvanised.
Lay the grid on your raised bed and step back to admire the orderliness! Great job, you built a square foot garden. Now, you can start planting all your delicious vegetables and herbs.
Planting Your Square Foot Garden
Once it’s all laid out, planting is simple. Keep the taller plants like tomatoes, beans, and trellised cucumbers on the north side. We don’t want them casting shade.
Sometimes is can be a challenge to decide how many plants you can fit in each square foot. There are a lot of helpful resources on this subject, including Mel Bartholomew’s books, but let me give you a few of the basics.
With larger root crops like garlic, onions and beets, you can fit 9 plants in each square foot. Smaller root crops like carrots and radishes can fit up to 16 per square.
Bush beans, bush peas, and spinach also grow best with about 9 plants per square foot. Larger greens like head lettuce, chard, and kale should be kept to about 4 plants per square.
With tomatoes, cabbages, peppers, and broccoli, stick to just one plant per square foot. Tomatoes, especially, will need a lot of pruning to keep them from taking over the bed. Pluck off the small suckers as the emerge to keep your tomato plants in their place. Plucking off the suckers will also help the plant focus on producing more fruit.
Squashes, bush cucumbers, and melons need two square feet per plant. This means that if you’re going to grow these spreading plants, you’ll need to keep that in mind while building your grid. Vining plants can be planted 6 to a square, and trellised up along the north side of the bed.
One of the pillars of the square foot garden method is crop rotation. As you harvest a crop, plant a new one. But don’t plant another crop of arugula in the same square as your old arugula crop. Plant it somewhere else, maybe in the radish bed. Grow another broccoli plant in the old arugula bed.
This constant rotation of crops confuses pests and puts different demands on the soil. As a result, your garden needs less upkeep in terms of pest control and fertilizing, and the visual pattern of the garden changes as well. It’s very appealing to see a variety of colors, shapes, and textures throughout the year.
Crop rotation also gives you the chance to focus on seasonal vegetables. Spring radishes can turn into fall broccoli; replaced spinach with arugula, and then kale can end the season in a bed of greens. There are so many opportunities to try something new with a square foot garden.
There are so many advantages to building a square foot garden: maximizing your harvest is just one of them. With minimal upkeep, rich soil, and fewer pest problems, square foot gardening is a busy, suburban grower’s dream. Square foot gardening wraps up all the loose ends of conventional gardening and ties them up into a neat little box of veggies.
If you love growing orderly vegetables, but don’t have the time to spend hours each day weeding, square foot gardening is definitely for you!