Square Foot Gardening – How to Plant Your Square Foot Garden Bed

220sqftgarden in Square Foot Gardening - How to Plant Your Square Foot Garden Bed and gardeningtipsOnce you have built your garden bed and decided on the accessories, it is time to plant the bed. Before you jump into a planting frenzy, you must first fill it with the appropriate growing medium.

Soil Structure

The best medium is made up of 1/3 blended compost, 1/3 peat moss, and 1/3 coarse vermiculite. The compost needs to be made of at least five different ingredients. Most commercially made compost generally is only made of two ingredients. The best approach is to make your own compost but if that is not possible, the commercially made compost can be enriched with garden scraps, poultry or rabbit manure, tea bags, coffee grounds, crushed eggshells, shredded newspaper, straw, hay, and/or grass clippings. Any combination of these materials will help enhance the commercially prepared compost.

Peat moss is an important ingredient for this soil mix because it helps the soil retain valuable moisture. But be careful when measuring the peat moss out because too much can create a waterlogged soil.

Both peat moss and vermiculite are natural ingredients that are harvested from the earth. Peat moss is similar to a soil while vermiculite is a mica rock that is mined from the earth. It is dug up and ground into small pieces. These pieces are then heated up until they explode. The exploded pieces can take the form of a powder and up to pieces the size of the end of your finger. These small pieces contain nooks and grannies where water can congregate. This water is always available to the plant’s roots when it is needed. This water storage is very important since plant roots grow around soil particles and not through.

After all the ingredients have been gathered, it is time to mix the medium. One way to do this is with a wheelbarrow but simpler way does exist and you do not have to worry about losing some over the side. The simpler way requires a large tarp, painter’s mask, watering hose with spray nozzle and ingredients listed above.

To begin the process, put the painter’s mask on and cut open the bags of compost if using commercial mixes. If using homemade compost, place the compost in a wheelbarrow and wheel to the tarp. Dump the compost onto the tarp and begin to mix. This process is easier to do with two people.

Mixing is done by each person grabbing a corner on the same side of the tarp and pulling the corners to the other side. Repeat the process with the other corners. This process turns the compost onto itself while mixing the ingredients.

Once the compost has been mixed sufficiently, empty the remaining bags of ingredients onto the compost. These ingredients can be a little dusty but applying a small amount of water can reduce the dust. To do this, gently mist the pile of material but be careful not to saturate the soil. Wet soil is very heavy and is difficult to mix.

Once the materials have been gently moistened, continue to mix the soil mixture as described above.

After all the soil has been mixed, drag the tarp with the soil to the garden bed. Shovel the soil into the garden bed and periodically dampen the soil with water. Continue to add soil until the soil depth is 6 inches. While this may not seem like a lot, it is all that is needed for this type of gardening. The only time you need additional amounts of soil is if you are growing crops such as potatoes.

Since this soil is so loose do not back down. Just take a rake and smooth the surface of the soil. It will settle on its own after awhile.

While you may feel that the bed is ready to plant, it is not. The grid system needs to be built before one can plant.


The purpose of the grid is to create individual planting areas in the garden bed. These can even be viewed as individual gardens where plants are only planted in the correct spacing. To see how this works consider a plant that requires 6 inch spacing. In one square foot of space, this means you can plant four plants or seeds.

The grid material itself can be as simple as string but I do not recommend this material. It is not very long lasting and does not provide a clear division. Instead consider using strips of wood, window blinds or even painter stir sticks. The material will depend on the size of the garden box and materials at hand.

Wooden slats or lathes can easily be found in home improvement centers and the best part is that they come in 4-foot lengths. To create the grid, lay out the lathes horizontally in 12-inch interval. Repeat the process vertically. Once all the lathes have been laid out, drill a hole at each cross section and secure with a small nut and bolt.

After the grid has been built, place it on top of the filled garden bed and adjust as needed. Drill a hole in the center lathe of each end and place a decking screw through the hole. This will secure the grid to the garden bed.

If you want to create a designer look, paint the lathes before placing them on the garden bed. Another approach is to leave them natural and write the names of the plants that you have planted in each square foot. This is especially important when you plant seeds or have not gardened long enough to recognize garden plants.

Planting the Grid

A well-planned square foot garden can produce three crops a season. Filling your garden bed in the early spring with cool-season crops produces the first crop. As the vegetables are harvested and if the weather allows, warm-season crops are filled in until the bed is full. Once the fall winds begin to blow, the warm-season crops will be done and it will be time to replant cool-season crops.

This pattern is called successive plantings and in square foot gardening this is very important. As soon as one plant is finished or completely harvested, another one will be put into its place. This increases yield and keeps the garden productive longer.

Before planting, one must consider the size of the plants. Extra large plants, such as broccoli, cabbage, and peppers need to be placed 12-inches apart. This means that these plants need to be placed in the center of one 12-inch square.

Large plants, such as leaf lettuce, Swiss chard, and marigolds need to be placed 6-inches apart. An easy way of doing this is to divide one square in half horizontally and then repeat the process for the vertical direction. It is easy to create these lines by simply drawing lines with ones finger. Once this is done, plant one plant in the center of each square created in the square foot space.

Medium plants, such as bush beans, spinach, and beets, require a 4-inch space between plants. This means that you can fit nine plants per square foot space. Dividing the square into nine blocks easily creates the space for the plants. Then simply place one plant or seed in the center of each one of these blocks.

Small plants, such as radishes, onions, and carrots, require a 3-inch space between plants. This means that 16 plants or seeds can be planted per square foot space. To divide the space into 16 parts requires three lines drawn in the soil in both directions. Once this is done the planting process is the same as above.

After the plants and/or seeds have been planted, water the garden thoroughly.

Square foot gardening creates a garden space that is easy to take care of and allows the gardener to question how much they really need. Through the process of planting each square, the gardener can personalize the space according to their needs, likes, and wants.

After the garden has been planted, the next step requires learning how to take care of it.


Mindy McIntosh-Shetter has been an Agricultural Science educator, and is a horticulture and/or environmental blogger who earned a degree from Purdue University in Agriculture Education with a minor in biology, and natural resources. Presently she is finishing up her Masters in Environmental Education and Urban Planning for the University of Louisville while working on her own agriculture/environmental blog.

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