How to Plan a Home Vegetable Garden Using the Square Foot Gardening Method

Planning a home vegetable garden can be tricky. Gardening is a science, after all! This article discusses the steps involved in planning a Square Foot Garden, which differ in several important ways from the steps involved in planning a row-based garden.

The first step is to select the vegetables you would like to grow, considering how much space you have available in your vegetable garden. Multiply the length of your garden bed by the width to calculate the available planting squares. The “available squares” must not be less than the squares required by the vegetables you select to grow. To calculate the planting squares required by each vegetable, use the “thin to” spacing requirements on the back of the seed pack and convert as follows:

  • 9 squares: “thin to” specification of 24 inches or greater; the plant is placed in the middle of a 9 square block
  • 2 squares: “thin to” specification of at least 12 inches, but less than 24 inches; the plant is placed in the middle of a 2 square block
  • 1 square: “thin to” specification less than 12 inches

When considering the total planting squares required, first calculate how many seeds of each vegetable you will need to plant, based on your harvest goals. For plants requiring more than one square, multiply the number of seeds by the squares required to calculate total planting squares. For plants requiring one square, determine how many seeds can be planted in the square based on the “thin to” requirement: 12 inches = 1 seed, 6 inches = 4 seeds, 4 inches = 9 seeds, 3 inches = 16 seeds. Then calculate the total number of planting squares required for these plants in order to reach your harvest goals. Add the two planting square calculations together, and this is the amount of space you will require in order to meet your harvest goals. Adjust as necessary to match the space you have available.

After selecting the vegetables to plant, the next step is to determine where to plant each vegetable in your garden. If a garden existed in the same location last year, remember to avoid planting a vegetable from the same family of vegetables in the same location in a three year cycle. Doing so will increase the risk that your garden will become infected with pests or disease. Placement of vegetables in a vegetable garden requires balancing a number of different factors:

  • Water Requirements: If you have more than one bed, group vegetables together based on water requirements and assign a targeted water level to each bed.
  • Plant Spacing: Plant the vegetables according to the plants per square calculations. Crowding vegetables can cause several problems, including loss of plants due to disease and lack of pollination.
  • Support Requirements: Some vegetables require a trellis. In the northern hemisphere, place trellises on the north and east sides of the bed to ensure the trellises do not cast shadows on the rest of the vegetables in the garden. In the southern hemisphere, place trellises on the south and east sides. Reserve these locations for vegetables that require a trellis.
  • Sunlight Requirements: Take note of the sunlight patterns in your garden. Areas that receive less sun should be reserved for plants with a Partial Sun requirement.
  • Height: In the northern hemisphere, place taller plants to the north and east sides of the bed to avoid casting shadows on the rest of the vegetables in the garden. In the southern hemisphere, place taller plants on the south and east sides.
  • Good / Bad Companion Relationships: Some vegetables are believed to have a positive impact on the growth or development of other plants (“good companions”), while others seem to cause harm (“bad companions”). Plant good companions close together, and keep bad companions far apart – ideally in separate beds.

The last step is to determine when to plant each seed. It can be difficult to determine exact dates, especially when seed packs use instructions like “plant in early spring”. The key point here is to understand the frost sensitivity of each plant. Plant each vegetable on the appropriate date based on expected weather patterns. Planting too late is just as bad as planting too early – since some vegetables do not tolerate hot summer weather.

Planning a vegetable garden can be time consuming, but if done incorrectly, can cause your garden to suffer. Therefore, it is worth the time you put into it. For those that do not enjoy planning, consider using a garden planner application. A good garden planner will generate a garden plan for you, taking into consideration all of the requirements discussed in this article. If you prefer to create your own garden plan, there are a couple of tools that can help with your vegetable garden planning process:

  • Graphing paper can be a valuable tool for planning the placement of plants. Place the graphing paper inside a plastic sheet protector and use a dry-erase marker to try different planting scenarios.
  • A spreadsheet can also be used for modeling your garden layout. Each cell in the spreadsheet represents a planting square in your garden.