What is Square Foot Gardening?

What is square foot gardening? Basically it is an intensive cropping system used in conjunction with both raised beds and open ground cultivation.

Which, whilst a definition, is not one that you may find terribly helpful. Instead, let’s look at a bit of clarification and explanation, so that you can decide if it’s a growing method that you would like to use in your own vegetable plot, allotment or kitchen garden.

A few key points to begin with, which we will look at in more detail in a minute: –

the basic element is a small square 1 foot wide and long
this is frequently a four foot by four foot square raised bed; this is then divided into sixteen squares, each of 1 foot
square foot gardening also works in borders, using the basic element as the starting point
plants are grown closely together
it gives a good harvest from a limited space – which can be useful in smaller gardens
as the raised beds are typically small, making covers or cages to protect plants is easy
the system can be used for ornamentals but is generally used for productive crops
it is a no-dig system of gardening – although the initial set-up may involve digging
once the initial set up is complete, ie raised beds and soil, it is relatively easy maintenance – more so when used with raised beds

How did Square Foot Gardening begin?

This growing system has been around since the late 1970’s / early 1980’s when the concept was developed by a civil engineer and amateur gardener, Mel Bartholomew. The phrase “square foot gardening” was the title of his 1981 book and both the phrase and the gardening idea took off.

Although well known in the UK gardening fraternity, it has been perhaps more widely popular in the states. There have been updates of Bartholomew’s book, which include introducing children to square foot gardening. He also had a TV show, taught others how to garden by this method and developed hi sown mix of soil / growing media for the square foot raised beds. As the mix includes peat, I am not recommending it to you.

It is a growing method that suits smaller urban and suburban gardens. For those who need to garden with raised beds, perhaps because of being in a wheelchair or with back issues, it can be a satisfying way to grow your own vegetables. The simplicity of the squares makes it an easy system for novice gardeners to understand.

Pro and Cons of Square Foot Gardening

Pros

high yields in a small area
a quick way to start a new garden – can start with just one 4 x 4 bed
raised beds can be stood on concrete
kits can be bought so raised beds can be quickly made
less wasting of seeds and seedlings
minimal regular maintenance
less weeding
fewer pests (in raised beds particularly)
easy to make / buy cloche covers for frost protection and extend growing season
if the raised beds are shallow and not fixed, then relatively easy to take with you when you move so highly suitable for rental accommodation
no digging, except possibly at set-up ( see relevant section below)

Cons

it can be expensive buying / building a few raised beds and filling them with fresh fertile soil
not all crops are suitable for square foot gardening
the 6 inch depth of soil in the beds recommended in Bartholomew’s updated book is too shallow for many plants, especially if their roots can’t extend into the soil below
shallow soil in raised beds tends to dry out faster than that in deeper beds and borders – you could spend a lot of time watering
weeding may not be less – even if you start with weed free soil there are likely to be airborne weeds seed; and, if your raised bed sits directly on soil, weeds can grow up into the raised bed
larger crops such as squash may take up more room
many perennial plants such as fruit trees and rhubarb are likely to outgrow their ‘square’

Planning Your Square Foot Garden

Probably the first thing you should do is decide which vegetables and fruit you want to grow. It sounds obvious, but you’d be surprised how many people start by building the raised beds first only to discover that they cant grow the long rooted carrots and parsnips they wanted to because there’s only a 6 inch depth of soil!

The basic concept is that you create a raised bed – 4 foot by 4 foot or 4 foot by 8 foot are common sizes. This is then divided into 1 foot squares, using a grid to mark this out can be a quick method, especially when you plan to have a few raised beds.

However you also need to decide on your growing method. For example, will you use a crop rotation system. If so, then making four beds, one for each family of vegetables will make your life easier.

But this is not the only system to use. In fact it could be argued that mixing crop types is a better policy when growing the plants so close together as it should confuse pests. But if you’d get confused too, then why not simply edge your beds with companion plants?

Each square is managed individually in the sense that you sow seeds or plant it up at a density based on plant size. I’ve made a few suggestions below, the list is not definitive and does sometimes depend on the cultivar used, and the size you want to eat the crop at and how deep your soil is: –

1 plant per square
Brussels sprouts
Cabbage
Celery
Kale
Lettuce (head type)
Potato
Sweet pepper
Tomato

2 plants per square
Celery
Cucumber (mini on trellis)
Kale
Lettuce (cos /leaf type)
Beans

4 plants per square
Carrots
Garlic
Onions
Parsnip
Spinach
Swiss chard

8 – 9 plants per square
Carrots
Kohl rabi
Parsnip
Radish
Spinach
Spring onions

12 – 16 plants per square
Carrots (to eat as baby sized)
Lettuce (cut and come again)
Radish
Spring onions

Setting up Your Square Foot Garden

Great, so we know what crops you want to grow and how many beds you’ll need. Where are they going to be built or placed in the garden?

Most fruit and vegetables grow best in a sunny position (but not always full sun all day) that is sheltered from wind. However, you can also grow in shady situations too. Crops that do well in shade tend to be the ones where you eat the leaves (there are Plews blogs on vegetables and herbs for shade).

It makes sense to have a water supply nearby, as it would for any vegetable garden. If you’re able to use movable trellis rather than fixed, then there’s less need to worry about climbing crops shading others.

If you are sure you will only ever grow crops that are happy in 6 inches of soil, then shallow raised beds are fine. But you may like to have 12 inch deep beds just to be in the safe side. If you’re setting these up on grass or a weedy soil, using a weed suppressant membrane or thick layer of cardboard in the base is a good idea.

Preparing the area can be done by digging – most likely double digging. This will depend on the state of your existing border soil and whether you’re making a new productive area on grass. Tips for double digging and soil preparation are covered in other blogs so I wont repeat here.

Once your raised beds are created you won’t be digging them, and you may like to start as you mean to go on. In which case check out the lasagne gardening blog. However, this option will take longer to be crop ready, so start it in the autumn / winter before your spring planting.

Square Foot Gardening – What Next?

As a growing method, square foot gardening works well in many situations and for many gardeners. But, like all systems it won’t suit everyone, and it may not suit everything you want to grow. However, there is sufficient flexibility to combine different methods within a single garden. For example, you could: –

use a row of single cordon apple trees to separate your vegetable plot from the rest of the garden
have a separate rhubarb patch next to the potting shed
grow potatoes straight into the ground or in their own potato sacks
use trellis to support climbing beans, outdoor cucumbers and smaller squash varieties so they fit into the 1 foot square
consider having some larger squares, perhaps 2 foot by 2 foot, for much bigger plants, so they still fit into the system
edge all your raised beds with companion planting such as marigolds

You can read about some other growing methods for gardeners in the link below.
And if you’d like gardening lessons to help you learn to grow your own veggies and where your garden is your classroom, do get in touch.
Plews can also design your kitchen garden or vegetable patch for you, taking into account all the important elements, your needs and your budget. Drop us an email for design in person and by video.