How to Get Started with Square Foot Gardening (and Why)

A little research on starting a backyard garden will quickly show there are many (maybe too many?) ways of garden planning. I’ve tried many methods of organic gardening over the years, like companion planting and crop rotation. One of the best for small spaces has been square foot gardening.

The square foot gardening method makes a tidy, productive garden possible. Even if it’s your first time growing your own food. It’s also a garden space that you (and the neighbors!) won’t mind looking at.

What Is Square Foot Gardening?

In the early 1980s, retired engineer Mel Bartholomew came up with the idea. His easily replicated concept grows more food in less space and was coined “Square Foot Gardening™.” The sfg method has only grown in popularity and the all new square foot gardening methods are an improvement on the original.

A Square Foot Garden has several unique characteristics:

1. Small, uniform raised beds (usually 4 x 4)
2. Rich amended soil as a growing medium
3. A physical garden grid dividing the surface of each bed into one-foot squares
4. A set number of plants per square foot

Square foot gardens can be a simple wooden frame. They can even become more elaborate vertical gardens:

I love the idea of a sprawling garden in all its glory. However, you can see how the tidy, small garden look of a square foot garden might be appreciated in a variety of residential settings. Especially if you’re tight on space or have an HOA to keep happy.

Square Foot Gardening vs. Traditional Gardens

In the traditional row garden, there are rows of bare dirt in between every long row of plants. These paths take up space in your yard. They’re also prime territory for weeds and compact nearby roots.

Now imagine a small 4 x 4 foot raised bed capable of growing the same amount of produce. The uniformly spaced plants crowd out weed growth. The ideal soil mix reduces the need for every inch of soil to remain aerated and fluffy. You can easily reach and tend to the raised garden bed. Plus the small footprint means big water savings.

Square foot gardening has an easy but precise formula to decide what to plant in each square foot. It’s based on how big a plant will get, so you don’t have to learn every plant’s spacing and nutritional needs.

Supporters claim you can get the same harvest with 80% less space and only a fraction of the effort. Here’s how to get started on your own square foot garden bed in a few easy steps:

How to Start Square Foot Gardening

Before you get started creating your new garden, there are a few things to keep in mind:

1. Size it up

No clever garden design can make up for a lack of sun or poor drainage. Track sun and shade patterns to find a location with 6-8 hours of sun in a level part of the yard. You also don’t want any trees or other obstacles blocking the rays from the southeast.

If possible, keep the vegetable garden close to the house. This will make watering and harvesting easier.

Consider how much food you want to grow. One 4 x 4 foot raised Square Foot Garden bed can produce enough food for a small family. However, you may want more if you plan to can or freeze some of your harvest. Leave 3-foot aisles between garden beds and mulch them well for weed control.

Garden boxes can also be raised off the ground in areas without green space and set at any height. These are also easy on the knees and back.

Now it’s time to get to work!

2. Make Your Bed

You can buy ready-made Square Foot Garden boxes in a variety of forms. With a few simple supplies though you can construct your own for much less. If you don’t feel like pulling out the power tools, some lawn and garden stores sell concrete forms for raised beds. All you do is slip the boards into the concrete block grooves and you’re done.

Here’s what you’ll need to build your own:

• (4) 2 x 6 in. boards, 4 ft. long, untreated (Cedar is a good choice)
• (12) 4 in. wood screws
• (6) 4 ft. lattice strips
• (9) machine bolts
• Weed barrier fabric
• Power drill
• Staple gun
• Screws/nails

This helpful video tutorial shows the process of building your garden bed step-by-step.

The boxes can be as decorative or as simple as you want them to be, depending on budget, time, and the surrounding landscape. Once you build your box you may also want to add a vertical trellis for climbing plants. Cucumbers, pole beans, zucchini, and even winter squash grow well on a trellis. Again, more produce in less space!

The lattice strips go on top of the finished planter box. They’ll form a grid or tic-tac-toe-style box of 16 (one-foot) squares. While this may seem strange at first, you’ll see why in step 4.

3. Mix the Perfect Soil Cocktail

For filling your new boxes, Mel Bartholomew, Square Foot Gardening creator, recommends his “Mel’s Mix” soil blend:

1/3 compost + 1/3 coarse vermiculite + 1/3 peat moss (by volume)

While paying for dirt may seem counterintuitive, genuine top-quality garden soil is the key to healthy thriving plants. It’s also a great way to cut down on fertilizers and pesticides. You’ll be glad you invested now to save time and produce down the road.

For a balanced nutrient mix, use a variety of compost sources, like chicken and cow manure, mushroom compost, and worm castings.

For one 4 x 4 foot garden box with 6-inch sides, you need 8 cubic feet of soil mix. Since it’s measured by volume and not weight, use a 5-gallon bucket to measure your ratios. Mix in a wheelbarrow or right in the garden bed.

Lay your weed block right over the grass inside the box in your desired location and fill it with the soil mix. Try not to compact it the soil though.

A Note on Vermiculite

Vermiculite is a naturally occurring mineral and is considered safe for organic gardening. Until 1990 though over 70% of all vermiculite was harvested from a Montana mine that was found to be contaminated with asbestos. The EPA opened an investigation into vermiculite insulation installed in older homes. The mine has since closed and current vermiculite sources undergo stringent testing for asbestos contamination.

If you prefer to not use vermiculite some sources recommend substituting sand or extra compost. You can usually find vermiculite at your local garden center or a farm supply store.

On to my favorite part of Square Foot Gardening: the planting grid.

4. Choose Your Plants (with Confidence!)

Think about your family’s likes and dislikes before you choose what to plant. Do you eat a lot of salads? Do you want to be able to make fresh salsa? If you have young children, go for fruits and veggies that are naturally sweet and easy to snack on. Snap peas, strawberries, cherry tomatoes, and carrot are some good ideas.

Fresh herbs are useful, easy to grow, and smell amazing. Certain herbs and flowers, like marigolds, even help deter pests and attract beneficial insects.

Here’s where the square foot grid comes into play. Look at the plant spacing (not the row spacing) on the back of your seed packet. From there you’ll think about the plants in terms of small, medium, large, and extra large:

• Small plants: 3” apart (or smaller) = 16 per square (radishes, beets, etc.)
• Medium plants: 4” apart = 9 per square (carrots, onions, etc.)
• Large plants: 6” apart = 4 per square (lettuces, etc)
• Extra Large plants: 12” apart = 1 per square (cabbage, broccoli, peppers, tomato plants, etc)

Melons, squash, watermelons, and other very large growers can be placed in the middle of four squares in the grid. Save space by training cucumbers and other climbing vines up a trellis attached to your garden box.

There are plenty of visual “cheat sheets” to take any guesswork out of the process. A time-saving tip for the ambitious: make your grid double as an irrigation system!

5. Planting and Maintaining Your Home Garden

Since your soil mix already has balanced nutrients, Square Foot Gardening helps reduce the need for more fertilizers and pesticides. Your growing plants will create their own living mulch.

• Add a scoop of compost to each hole before planting.
• Keep the plants evenly watered until they sprout.
• Weed around plants as needed, catching them when they’re small. This will help prevent weed seeds from spreading.

Raised bed gardens have another bonus. Cold frames or pest-deterring frames can easily be designed and fit to the 4 x 4 box. A box made from 4-foot 2 x 2 boards and chicken wire makes a tidy and not too unattractive floating cover. This prevents garden pests from stealing your precious fruits and veggies. It’s a lifesaver for strawberry patches and tender greens.

Final Thoughts on Square Foot Gardening

While SFG is still a popular method, it’s not the only thing to consider when cultivating a healthy garden. Intercropping and companion planting are still good ways to keep soil healthy. You can easily combine the two methods for even more success. You also don’t have to grow everything in a 4×4 raised bed.

Branch out and try shrubs around your yard perimeter or containers on your back porch. Creating a garden that’s part of your home landscape is a beautiful and holistic way to grow veggies, fruits, and flowers. As we learn more about regenerative agriculture, these methods are starting to replace monocrop rows. Square foot gardening beds are just one way to incorporate healthy plants into your backyard garden.

Have you tried a Square Foot Garden? What advantages have you found? Disadvantages? Share your best tips in the comments below!