Square Foot Gardening Intro: How To Build & Maintain Your Productive Plots

Do you want to grow your own food but are unsure if you have enough space or time? You're in luck because there is one vegetable gardening method that doesn't require tilling or intensive labor. Once you build or buy a few gardening beds, you'll be all set to start planting your own fresh herbs and vegetables. Here's your beginner's guide to starting and maintaining a square foot garden.

Square foot gardening is a method of growing vegetables and herbs in a small amount of space. Mel Bartholomew, a civil engineer and efficiency expert, came up with the square foot gardening method in 1976 and wrote a book, which was updated in 2007 and retitled All New Square Foot Gardening.

This method has helped people of a broad range of ages, gardening experiences, and physical abilities grow their own vegetables and herbs, explains Kim Roman, a square foot gardening certified instructor and author of How To Garden Indoors & Grow Your Own Food Year Round.

"[Starting a square foot garden] is an easy way to get the most productivity from a given amount of space," says Margaret Mishra, garden expert and creator of The Gardening Me. Novice and experienced planters can both benefit from creating one, especially if they want to grow plenty of vegetables in a limited space while maintaining an organized garden.

"Square foot gardening is the practice of dividing a plot into square feet and using it as a guideline for the number of plants to plant per square foot, depending on variety," says Chia-Ming Ro, garden consultant and owner of Coastal Homestead. "It will look like a tick-tack-toe grid," Roman adds.

If you're wondering what differentiates this style of garden from growing rows directly in the ground, Roman explains that it basically eliminates the need to rototill, or turn and break up the soil, thereby reducing the amount of manual labor required.

"Compared to a single row garden where you must rototill a large area every year or two, square foot gardening gives you 100% of the harvest using only 20% of the space, 10% of the water, 5% of the seeds, about 2% of the work, and virtually no weeds," she says.

There are a variety of benefits of having a square foot garden (SFG for short), but there can be a couple of drawbacks too. Here are the main pros and cons our experts cite:

Some vegetables and plants are better suited to this technique, namely those that don't take up too much space and don't have tall roots.

However, this doesn't mean you can't include these plants in your SFG. You'll just have to get creative with how you place them. "Supporting the taller and/or vining plants by adding a vertical trellis and using ties to help them climb will really keep things tidy and maximize the space," says Ro. Roman adds that popular plants like spaghetti squash and vining tomatoes can be grown using this method.

"Beds can be made from all sorts of materials from logs to bricks to stones, but usually you would use wooden boards," says Mishra. Here is an overview of what you'll need to build one.

The size of the raised bed you build is key because you want to ensure it's manageable and you can access each square for watering, weeding, and harvesting. "As with any growing method, beginning gardeners should start small—no more than three 4-feet-by-4-feet raised beds (or a total of 48 squares)," Roman recommends.

Your bed's location is important since it will influence the square foot garden's design and size. A rule of thumb when figuring out just how wide to make the garden bed is, "The average-sized adult can comfortably reach 2 feet," says Roman. Therefore, if the grid is up against your house or a fence, it should only be 2 feet wide.

"If you can walk all the way around the bed, it can be a maximum of 4 feet wide so you can access the center of the bed from any side," Roman adds.

However, there are exceptions! It's important to consider the needs and heights of the people who will be tending your garden. "If you're a petite adult, or creating a bed for a child, your reach is probably 18 inches, so you'd make the bed no wider than 3 feet," says Roman.

Another factor you'll want to consider when planning your bed is sunlight. What area of your yard tends to get the most sun throughout the day? "I planned my beds so that they were oriented from east to west lengthwise so that they captured the sun all day; placing taller plants on the north sides of the bed means that shorter plants are not shaded," explains Mishra.

Now that you've decided on the size and location of your garden, you're ready to buy your beds or build them using the materials above. Bartholomew's book is a great guide if you're going the DIY route.

For growing in beds, a lightweight mix that gets good drainage will be best. "We use what we call Mel's Mix, which is a soilless growing medium," says Roman.

To mix up this combination (named after the creator of the method), you'll need one-third by volume of fluffed peat moss (or coco coir/fiber), one-third coarse vermiculite, and one-third of a good blended compost. You can also buy a premade mix online.

Since you'll need a fair amount of mix to fill your containers, this step can be pricey. However, once your mix is down you won't need to replace it for years (more on that below). From there, all that's left is to start your seeds.

These expert tips will help you nail every aspect of caring for your new square foot garden.

Ensuring that your plants receive enough sunlight makes the difference in having a thriving garden and reaping the rewards at harvest time.

"If you're eating the leaf, you can get away with four to six hours of full sun," Ro gives as a general rule of thumb. "If you are eating the 'fruit' you're going to want eight or more hours of full sun. 'Fruit' here refers to anything that flowered and you're eating the pollinated result."

Some plants can do with more or less sun so it's a good idea to plan out your SFG and know what the preferences of your plants are. "Always check the plant label or seed packet to see how much sun each crop needs," says Roman. "Group all full-sun or partial-shade crops in separate raised bed locations."

"Mel's Mix lasts 10-plus years and you only need to add an inch or two every couple of years as the soil level drops from it sticking to plant roots and what's used by the crops," says Roman.

But if making Mel's Mix isn't possible or you prefer one less thing to do, Jo Ellen Meyers-Sharp, gardening coach and creator of Hoosiergardener, suggests, "Get a good planter's mix from a landscape supply company; a planter's mix has soil, compost, and other organic matter." 

There are several factors that will influence how much water your SFG needs. "Watering will be highly dependent on region, irrigation set up, and flux in weather," says Ro. The moisture in the soil will give you clues on whether you need to water or not.

"If the soil about 1 inch below the surface is dry, then the bed needs watering," says Mishra. If you're curious how often this may be, Ro explains, "Loosely, you will most likely need to water deeply one to two times a week and top off the beds every couple of days."

The only time that light, shallow watering is best is when you have just planted seeds and you're waiting for them to germinate. Then, you'll need to water one to two times per day until seeds sprout, says Mishra. 

With these final expert tips, you'll be ready to start dreaming up what will go in your square foot garden this season:

Square foot gardening allows you to grow a number of different plants in a very small space. Though the method takes some planning and preparation to pull off (get those garden journals ready!), it can eventually leave you with lots of fresh food for relatively little effort.