How to Do Square Foot Gardening: A Complete Guide

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What Is Square Foot Gardening?

Square foot gardening is a technique of creating small yet highly productive kitchen gardens. It allows people to grow more food in limited spaces, promoting output, and reducing waste.

how to do square foot gardening
person planting within grids

The concept was invented by a retired engineer and backyard gardener, Mel Bartholomew, as a modified version of vegetable gardening in his first book, which was published in 1981. By using his scientific mind and interest in gardening, he created a concept that focused on the efficient use of space and resources.

The concept is simple. Create a small garden bed (usually 4 feet by 4 feet or 4 feet by 8 feet) and divide it into smaller square grids of 1 foot each. All grids are managed individually and seeds of different vegetables are planted in one or more squares. Since there are no paths between the grids, the soil in the bed stays loose because nobody steps on it, and there is no space that is wasted.

The number of crops planted in each square depends on the size of the plant. For instance, you may plant 16 small crops such as radish or rocket salad in one grid, but only one large crop of broccoli or cauliflower in the same space.

About twenty-five years later, Bartholomew further modified his original method of square foot gardening. He advocated for the creation of 6-inch deep frames or raised beds, filling them with a mixture of compost, vermiculite, and peat moss to crop plants instead of garden soil mixed with compost.

The raised beds and new soil mixture promoted a method of planting crops more densely as compared to traditional row layouts. This works ideally for those who have limited space or are new to growing and do not want to be overwhelmed with a large patch of harvestable land.

Overall, the system also promotes variety – allowing you to plant a different crop each time and experiment with a variety of fruits, vegetables, and herbs. Since they are extremely easy to start with, square foot gardens work well for beginners and children. They are also healthy means to grow your own food and create an edible organic garden in your own backyard.

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Read on to find a basic guide on how you can do square foot gardening:

Step by Step Guide to Start Your Own Square Foot Garden

Starting your own square foot garden can sound technical and overwhelming. However, we have laid out simple steps for you to follow. From creating your garden bed to harvesting your crops, learn how to do square foot gardening:

Step 1: Plan Your Garden

Once you’ve decided to create your own square foot garden, the first thing you want to decide on is a location. To choose the ideal spot, identify which direction your garden faces with the help of a compass or a compass app on your smartphone.

Most plants grow best in sunny locations however, you can locate a spot that’s slightly shady as well. Plants that grow well under the shade tend to be leaf-based, such as spinach, rather than the ones that are root-based, such as potatoes and carrots.

Your square foot garden should be at an accessible location. Not just from you, but a regular water facility as well. The reason for this is because you are more likely to care for your plants if you can see them every day, and keep a close eye on their sprouts and timely progress.

Step 2: Imagine Your Crops

how to do square foot gardening
huge variety of vegetables

As you identify the perfect location for your square foot garden, it is now time to plan the crops you’d like to grow. If you’re confused about where to start, consider what you and your family most like to eat, and products that are not readily available in the market.

Create a rough sketch of your overall box and plan what crops to plant in each grid. Taller plants should be planted at the back of the bed while smaller ones in the front, so the larger ones don’t hinder sunlight exposure for the rest.

At this stage, you should also be considering crop rotation and planning. This means to avoid growing vegetables from the same family in the same bed on a yearly basis in order to reduce pest and disease contamination. Some plant families include legumes (peas, runner beans, broad beans), onions (leeks, garlic, onions), roots (beetroot, carrot, parsnip, celeriac) etc. 

Step 3: Build Boxes and Grids

You can either buy pre-built square foot garden frames from the market or keep costs down by creating your own. All you need is reclaimed wood or solid material such as bricks, concrete blocks, stones and logs lying around in your garden.

Once the outer frame is set, create the inner grid to form each square. The grid can be measured creating a large-scale measuring tape or a string to demarcate 1 foot to each square. You can also use materials such as wooden dowels or thin strips of wood to create your grid.

Tip: Once you set your outer frame, place a piece of large cardboard underneath the box. Essentially, they act as the ‘base’ of your bed if you are planning to create your square food garden in live grass. The cardboard helps to kill the grass and it decomposes under the soil, eliminating any sort of weeds to grow in the new bed.

Step 4: Fill Your Garden

Once your frames and grids are ready, it’s time to fill your garden bed. You can choose to follow Bartholomew’s unique soil called the Mel Mix – a mixture of compost, vermiculite and peat moss, each one-third in quantity.

However, it is important to note that peat is not as sustainable as other options and the horticultural industry is taking measures to eradicate its use in planting vegetable gardens. An eco-friendly alternative is a mixture of peat-free compost, fine gravel, and chipped wood bark. The gravel and wood bark help to retain water and contribute to a more efficient drainage system.

If you are just starting out, it is not necessary to create your own garden compost. However, once you get more comfortable with square foot gardening, consider your own mix to reduce waste and save gardening costs.

Step 5: Start Planting

Your initial planting method depends on where you are located. Most of the time planting involves sowing seeds directly into the ground. However, if you live in colder regions, you can start your planting technique in a glass indoors to prevent any sort of initial frosting.

One key factor to note is that each fruit, vegetable, or herb is planted in unique amounts within a square. This ensures maximum use of space and not overcrowding your garden bed to prevent plants from growing to full capacity. Here is a brief guide to understanding the spacing requirements for some of the most common types of crops:

One Plant per Square Foot

Some of the largest plants can easily fit into a one square foot grid. Simply form a hole in the center of the one by one-foot square, and transplant your seedling in it. Some examples of large plants include eggplant, celery, kale, parsley, sweet potatoes, potatoes, tomatoes, cabbages, and herbs such as rosemary, oregano, and sage.

Two Plants per Square Foot

The seedlings of some plants can be planted side by side in one square grid at a recommended planting distance. Examples of these plants include cucumbers, winter squash, cantaloupe, and pumpkins. 

Four Plants per Square Foot

To crop four plants per square foot, place each seed in the four corners of the square at equal distances from each other. They should not be exactly at the border of the grid, and only slightly away from it so the plants don’t clash with other grids. You don’t necessarily have to plant all four in one grid, decrease the seed quantity as per your liking.

Some plant examples for this type of grid include basil, lettuce, zucchini (with cage), tomatoes (with cage), swiss chard, etc.

Eight or Nine Plants per Square Foot

In order to crop eight to nine plants in one grid, form the shape of an internal square. This means that each seed is planted equidistant from the other and placed in quantities of 3 in length and width (i.e. 3 plants long and 3 plants wide).

Plants in this category include peas, turnip, spinach, cilantro, beets and parsnips etc.

Sixteen Plants per Square Foot

Similar to the way eight or nine plants are cropped in one grid, sixteen seeds are planted using no more than 4 plants long and 4 plants wide. It may get slightly tricky to plant sixteen crops per square foot, so you can avoid overcrowding by decreasing the number.

Some examples in this category include carrots, parsnips and radishes. However, if you don’t plan to pick any of the vegetables regularly, this option is not ideal as it leads to bolting or disease without regular checks.

Step 6: Maintain Your Garden

how to do square foot gardening
compost mix on a blue shovel

The key to maintenance is to make sure your plants get enough water. Overwatering is also detrimental so you have to make sure the quantity and time of water remain consistent throughout the planting process. Additionally, don’t let your plants dry out because it can get extremely difficult to recover them and you may have to restart the whole process.

A compost mix that is already rich in nutrients means that your crops don’t need any more ‘food’. All they require is water, sunlight and a constant check so large plants do not hinder the growth of smaller ones. Once the crops have been harvested, replace the compost so that newer nutrients are ready for a fresh batch of plants.

Step 7: Harvest the Crops

Harvesting needs to be done at the correct time. You don’t want to wait until the crops are their largest size before you harvest them. Some plants such as carrots, peas and beetroot taste much better when they are harvested young.

Additionally, harvest crops when you are close to consuming them. You want to eat the plants fresh and not let them sit in the refrigerator for too long. For this reason, pre-plan your harvests and dinner times so they both correlate and give you a healthy meal.

If you’ve planted too many seeds and end up with excess crops, you can always create natural home-made jams and chutneys to accompany your meals.

Now let us see the pros and cons of square foot gardening.

Pros of Square Foot Gardening

Below are the list of pros of square foot gardening.

High Output

Intensive planting in your backyard or garden means you’ll harvest tons of crops in a limited space. The amount of yield you receive varies upon you and if you go for sixteen plants per square foot, you can easily end up in excess.

Convenient Set-Up

Square foot gardens are easy to set up and require minimal maintenance. If you’re a starter, you can easily buy a raised bed and simply create the grids to get your square garden started. Furthermore, since the garden is small, it does not require a large number of tasks for maintenance. The size allows you to plant, maintain and harvest your square foot garden all at once.

Less Weeding

Depending on the compost you use, square foot gardens are popular due to the lack of weeds present after the first batch. Thus, you don’t need to spend hours under the sun pulling weed from the ground to plant your next batch of crops.

Cons of Square Foot Gardening

Below are the cons of cons of square foot gardening.

Insufficient Depths

The depth mentioned in Bartholomew’s book is too shallow for some plants, especially if their roots cannot extend into the soil below. To mitigate this issue, you need to enlarge the bed frame and make it at least 12 inches deep so more compost can be added.

Excess Irrigation

As mentioned above, the crops require regular water. In garden beds like these, soil tends to dry out faster. This means that excess irrigation is required so the plants continue to receive the nutrients they receive. You also have to be mindful of overwatering as that can be harmful to the growth of your plants as well.

Initial Costs

The costs of building a garden bed and filling it with compost can be slightly expensive. For someone just starting out and who doesn’t want to invest too much energy in creating a bed from scratch, initial costs may be high as they’ll need a solid structure for the crops to grow.

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The Key Takeaway

Now that you are well-versed on how to do square foot gardening, it is time to start yours right away. Remember all the important points mentioned above, start planning, and remember to stay consistent till the crops yield. Happy gardening and happy eating!

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