Square Foot Gardening

What is Square Foot or Square Metre Gardening?

Square Foot Gardening (SFG)/Square Metre Gardening (SMG) has now become popular around the world, for a number of reasons.

SFG is basically an intensive, shallow, raised bed system.  Growing in a mixture high in nutrients and organic matter.  A small system obviously doesn’t take up much room in a small yard, and watering can be efficient and overall water use reduced – another benefit.  American Mel Bartholomew is the ‘founder’ of Square Foot Gardening - a concept that he launched in 1981.  He has published books and made TV shows in the US of the method. 

The ideal SFG is a square bed 4ft x 4ft (1.2m x 1.2m) divided up into a grid with 16 smaller squares within, or a Square Metre Garden (1m x 1m) divided up into 9 smaller squares. 

The concept is to devote one ‘square’ to a particular type of plant.  How many plants you put into that ‘square’ depends on the ultimate size of the plant.  Larger plants (ie. Tomato, basil) you would only plant one in the centre of a square.  Smaller plants, (ie. Strawberry, lettuce) - 4 per square.  Even smaller plants (ie. Spinach) maybe 9 per square, and smaller again (ie. Radish, onion) maybe 16 per square.

The idea is to have the grid clearly visible and dividing the larger bed.  Because the overall size of the bed is only 1m or 1.2m, it is easily reached from all sides, so you don’t need to step onto the bed or compact the soil.  Tending and harvesting is not difficult.  Smaller beds are also easier to work with if you need to provide shadecloth or frost protection; depending on the seasons.

Because many crops are grown close together, the benefits of companion planting come into play – pests can get confused with the range of plants on offer!

What are the details of a SFG/SMG?

It is recommended that the grid box be laid on top of existing soil or lawn with weed mat underneath, and filled with ‘Mel’s mix’ - his researched blend of 1/3 compost, 1/3 peat moss and 1/3 vermiculite.  Green Life Soil Co has produced our own version of 'Mel's mix', tailor made for Perth's conditions.  We don’t use peat moss (due to it being unsustainably sourced) instead we use cocopeat; which serves a very similar purpose.  We mix it with compost, vermiculite, Charlie Charcoal biochar, and a touch of extra nitrogen and mineral trace elements to ensure your vegies get all they need from the growing medium.

The depth of soil is only required to be about 20cms - so there are also savings over a conventional garden bed as less soil is required.  Because the mix is a highly fertile and water holding mix, a depth of 20cms (usually considered too shallow) will work.  However, for crops like potatoes or carrots, a topper box to sit on top of the original square to provide additional depth is certainly recommended.

At harvest time, in SFG, the crop is removed - often cut at the base to allow roots to decompose within the mix - and a fresh seed or seedling planted in the same spot,, with a trowel full of new soil.  Of course, many salad greens (lettuce, spinach, silverbeet, kale) can be harvested from a young age by taking a few outside leaves every few days.

Within the system, planting guides and recommendations for things like crop rotation have been published, so it makes it easy for a new gardener to have relative success and avoid pitfalls of overcrowding.

Spreading plants like pumpkins and cucumbers are grown vertically, using a trellis system - again saving space.

These are the 10 basics of Square Foot Gardening - taken directly from www.squarefootgardening.org

1. LAYOUT - Arrange your garden in squares, not rows. Lay it out in 4′x4′ planting areas.
2. BOXES - Build boxes to hold a new soil mix above ground.
3. AISLES - Space boxes 3′ apart to form walking aisles.
4. MEL’S MIX - Fill boxes with Mel’s special soil mix: 1/3 blended compost, 1/3 peat moss, and 1/3 coarse vermiculite.
5. GRID - Make a permanent square foot grid for the top of each box. A MUST!
6. CARE - NEVER WALK ON YOUR GROWING SOIL. Tend your garden from the aisles.
7. SELECT - Plant a different flower, vegetable, or herb crop in each square foot, using 1, 4, 9, or 16 plants per square foot.
8. PLANT - Conserve seeds. Plant only a pinch (2 or 3 seeds) per hole. Place transplants in a slight saucer-shaped depression.
9. WATER - Water by hand from a bucket of sun-warmed water.
10. HARVEST - When you finish harvesting a square foot, add compost and replant it with a new and different crop.

If you are after a complete kit for your SMG check out - The Vegepod (see photograph above) is a self contained kit that comes with its own removable cover for pest & weather protection of your crops.

Download your FREE 9 page guide to Square Foot Gardening by clicking here.