Square Foot Gardening or SFG is an excellent solution for gardeners who lack space but want to start a vegetable garden. Using a simple 4 by 4 feet raised bed, this technique helps you grow dozens of crops even in a small garden, producing higher yields with less effort.

This guide will take a close look at what makes this method so popular, and provide top tips on setting up, using the Square Foot Gardening planner, and preventing any common problems you may encounter.

What is Square Foot Gardening?

Square Foot Gardening is a raised bed gardening technique developed by engineer Mel Bartholomew in 1981. It uses a 4 by 4 feet bed divided into 16 one-foot squares. A different crop is planted in each square and, depending on the variety, it can grow anywhere between 1 and 16 plants in a single square foot. 

This technique was devised as an alternative to row gardening, which used to be the norm for centuries. But while a row layout makes sense in a farming setup, as it allows easy access for machinery, it’s not always suitable for smaller spaces. 

Square Foot Gardening has several advantages including:

•  It takes up less space;
•  It doesn’t need digging or tilling;
•  It requires less water and fertilizer;
•  It uses fewer seeds;
•  The dense planting leaves less space for weeds to grow.

Thanks to these perks, SFG has become increasingly popular in home gardens, urban gardens, allotments and community plots.

How To Set up a Square Foot Garden

Setting up an SFG is a simple job you can do in a single afternoon. Here’s what you need to know to get started:

Location

Try to place your bed in a full sun position. Square Foot Gardening is an intensive growing technique, so you want to give your plants the best chance of healthy growth.

SFG beds are open at the bottom, so always use landscape fabric underneath them to reduce the risk of grass or weeds growing through. Alternatively, you can lay down two layers of cardboard. This will smother the weeds and allow plant roots to grow into the soil underneath after the cardboard breaks down. 

Materials

You can build SFG beds from untreated wood, galvanized steel, or reclaimed materials like bricks or cement blocks. To mark your grid, you can either use string, or bamboo canes tied together. 

Size

The standard size for Square Foot Gardening beds is 4 x 4 feet. If the space allows it, you can further increase that to 4 x 8 and even 4 x 12 feet. The golden rule is to avoid stepping on the soil, so don’t make your beds wider than your arm can reach. But if a width of 4 feet doesn’t work for you, you can reduce it to 3 or even 2 ft.

The height of your raised beds should be a minimum of 6 inches. This works best for crops with shallow roots, like radishes and salad greens. If you’re growing crops like tomatoes, beans, or carrots, a minimum height of 12 inches is ideal. 

Soil

Mel’s soil mix for Square Foot Gardening consists of equal parts compost, peat moss, and coarse vermiculite. For best results, Mel recommends using five different types of compost, including well-rotted manure, worm castings, and mushroom compost.

Best Plants for Square Foot Gardening

You can use SFG to grow almost all fruit and veg you would grow in a regular raised bed. The main aspect to pay attention to is spacing, and how many plants you can grow in each of the one sq ft grids.

This Square Foot Gardening spacing chart contains some examples of popular crops you can grow:

*Includes basil, oregano, cilantro, dill, fennel herb, mint, and parsley.

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How much to plant depends on your space and needs, but you can use this vegetable production chart to get a rough idea. 

Not all crops are suitable for Square Foot Gardening. Perennials like asparagus, artichokes, rhubarb, and fruit bushes take up lots of space, develop extensive root systems, and will outcompete your annual crops.

6 Tips To Maximize Your Square Foot Gardening Yield

You can easily grow over 100 plants in one bed using Square Foot Gardening. But remember: this is a very intensive growing technique. And if you’re not careful, you can end up with a mass of tangled crops, or worse, weak and struggling plants.

These six tips will help you prevent the most common Square Foot Gardening problems.

Plan Your Layout

Always put your tall plants at the back of the bed, and the smaller ones at the front. Tall plants or crops that need supports, such as tomatoes, cucumbers, or beans, should be placed on the north-facing side of the bed, to avoid shadowing the smaller crops in front of them. Meanwhile, crops such as pumpkin, watermelon, sweet potatoes, or dwarf beans should be planted around the sides, so they can sprawl over the edges of our bed.

Provide Airflow

The downside of Square Foot Gardening is that having lots of plants growing close together can encourage the spread and accumulation of diseases. An easy way to prevent that is by providing sufficient airflow. Use stakes to support leaning plants, and regularly remove any damaged or wilted foliage, especially from the bottom.

Use Fertilizer

In his books, Mel Bartholomew advocates that his soil mix reduces the need for extra feeding. However, he also recommends replenishing the compost after harvesting and replanting each square. This can quickly become a costly and time-consuming task.

A simpler alternative is using a monthly or biweekly application of organic fertilizer, such as liquid seaweed. This will help your plants stay healthy and productive, especially when practicing succession planting.

Mulch

Apply a layer of one or two inches of mulch to your beds. This helps suppress weeds, retain moisture, and provide extra nutrients as it breaks down. Use biodegradable mulches such as straw, grass clippings, shredded leaves, or just compost.

Photo by RDNE Stock project

Succession Planting

Avoid leaving empty squares after harvesting your plants. This will prevent any weeds from popping up, and ensure you can harvest more produce from the same bed. So when one crop has finished, refill the square with either seeds or transplants. 

Encourage Diversity

Planting different crops in the same bed helps reduce the risk of pests and the buildup of pathogens. Companion plants also play a vital role in attracting pollinators and beneficial insects. Allocate one or two squares to plants such as marigolds, nasturtium, sweet alyssum, and poached egg plant.

Conclusion

Many gardeners are put off by growing their own food because they believe it takes up a lot of space. If this applies to you, why not give Square Foot Gardening a try? You’ll be pleasantly surprised to discover that creating a vegetable garden is not as difficult as you thought.