Square Foot Gardening
Written by: Doug
Published: 20th December 2018
Square Foot Gardening
An Expert Guide Written By The Bonnie Gardener
My name is Nicola – I’m also known as the Bonnie Gardener. I started gardening when I was six years old and my parents gave me an area of our garden to tend. Nature and the great outdoors have always been a big part of my life, but when I left home and went to university, I lived in tenement flats and didn’t have the luxury of my own outdoor space.
When I was in my twenties I got lucky and reached the top of a very long waiting list for an allotment plot. From there, my insatiable desire to learn everything I could about plants – including growing vegetables and flowers – blossomed. I studied horticulture with the Royal Botanic Gardens in Edinburgh, got my qualifications and took the decision to leave a full time corporate job and become a gardener. The Bonnie Gardener was born and I have never looked back.
What I love most about gardening is that every day is a school day – the more I learn, the more I discover that I need to learn more. Gardening is not something to be scared of, nor should it be seen as another household chore – it is fun, it is creative and it is incredibly rewarding.
In this article I want to answer the question that so many of you have been asking Highland Titles – ‘What exactly can you do with a square foot of land?’ It is a great question and the answer is of course wide and varied, but a super interesting thing you could do is embark on a tried and tested gardening technique called ‘square foot gardening’.
Using the words and videos below, I’m going to share with you the ins and outs of this gardening method, which was dreamt up by an American man called Mel Batholomew in the 1980’s.
I will cover
- what square foot gardening is
- how to go about planning and creating your own square foot garden, and
- some handy dos and donts to keep you on track
- pros and cons of square foot gardening
Intrigued? Read on to learn more.
What is Square Foot Gardening?
An engineer rather than a horticulturalist by trade, Mel Bartholomew coined the phrase ‘square foot gardening’ in his first book on the subject which was published in 1981. By applying his orderly and scientific mind to the somewhat chaotic world of kitchen gardens, he created a simple system which was efficient with both space and resources. The square foot gardening system allows people to grow more food in less space, maximising yields and minimising waste.
In square foot gardening, raised beds that are 4ft (1.2 m) square are created and filled with growing matter (more on this later). The bed is then separated into sixteen one foot squares to form a grid. Each of the squares is then planted with a different crop.
The number of plants you put in each square depends on the size of the individual crop, so for example you might plant 16 of a small crop such as radish or rocket salad, four of a medium-sized crop such as round lettuce or strawberries, or one of a large crop such as broccoli or cauliflower.
The magic of creating beds that are one square foot in length and breadth is that the crops are easy to tend to, without having to step on the bed or lean too far to harvest them. A raised bed is also a good way to grow as you won’t ever step on the bed and create compacted soil, which would then be difficult to plant into.
Crops are planted more densely than they would be in a traditional row layout vegetable garden, which makes the method perfect for people who have limited space or are new to growing and don’t want to be too overwhelmed with a huge patch or allotment plot.
After each square is harvested, you then plant another, different crop, allowing for a continuous harvest. The magic of the system is that it encourages you to try a huge variety of fruit, vegetables and herbs. By choosing to square foot garden you will not only learn new skills but you’ll be healthier as a result – eating that metaphorical and aspirational rainbow that so many health practitioners talk about.
Square foot gardening is a very basic system and it is perfect for beginners and children. Simply follow the steps below and watch our simple videos to discover how to do it yourself.
The 8 steps of square foot gardening
Planning your garden
Once you’ve decided to embark on your square foot gardening journey, the first thing to decide is where to locate your new garden bed or beds. There is no reason why you can’t dedicate 5, 10 or 15 square feet to square foot gardening, although one might be enough to get you started!
To choose the perfect spot, identify which direction your garden faces using a compass or a compass app on a smartphone. Most fruit and vegetables grow best in a sunny position that is sheltered from wind but you can also grow in shady situations too. Crops that do well in shade tend to be the ones where you eat the leaves, such as chard and spinach, rather than the ones where you eat the roots, such as potatoes and carrots.
Try to locate your square foot garden as close to the house and a water supply as possible. The reason for this is simple – you are much more likely to take good care of your crops if you see them everyday, check in with how they are doing, and don’t have to go out of your way to tend to them.
Ideally locate your square foot bed backing onto a vertical structure such as a wall or fence, This can be handy for growing climbing vegetables such as peas and runner beans.
You can square foot garden on top of paving, grass or an existing bed. If you opt for paving, I would advise you build a frame that is double the depth of Bartholomew’s suggested 6” – particularly if you want to grow root vegetables such as parsnips and potatoes. If you are growing on grass, lay a weed suppressing membrane or cardboard cover under the frame to prevent the grass growing through. The most ideal site for a square foot bed is on top of an existing bed, so the vegetables can grow through to the ground beneath.
One of the most exciting things about gardening is planning what you want to grow. If you aren’t sure where to start with fruit and veg I recommend you grow things that you and your family like to eat, as well as produce that isn’t readily available in the supermarket (see my growing guide for beginners at the end of this article). I can only get purple beetroot in the shops, so I love growing the golden coloured ones in my plot – it is gorgeous roasted in the oven and tossed together with rocket leaves for a winter salad.
At this stage you should do a sketch of your 16 square foot boxes and decide which crop should go in which box. Grow taller crops at the back of the bed, and smaller ones at the front so that the larger ones don’t create too much shade for the smaller ones. If you want to grow climbing vegetables, situate these at the back of the bed near the supporting vertical structure we mentioned in step 1.
At this stage it is helpful to start thinking about crop rotation and companion planting.
When I first started gardening I found this very complicated but it is quite a basic concept. Basically speaking, you should avoid growing vegetables from the same family in the same bed year after year to reduce the risk of certain pests and diseases. Plant families include brassicas (broccoli, cabbage, kale); legumes (peas, runner beans, broad beans); onions (leeks, garlics, onions); potato family (potato, tomato, pepper, aubergine); roots (beetroot, carrot, celeriac, parsnip, etc).
To keep things simple, square foot gardeners could choose to have three or four beds in their garden. You can then practice crop rotation with one bed assigned to each group, moving it along one bed per year.
Companion planting is also something well worth thinking about. Again, it can sound complicated, but it is quite simple and straightforward. Plants, just like people, can be really good for one other and create mutually beneficial relationships. For example, some plants can help reduce the incidence of pests or disease in their neighbours. Marigolds are a fantastic plant for a square foot garden as they will attract ladybirds and hoverflies which will help to pollinate your crops.
Planting strong-scented chives beside your carrots will help to deter the terrible pest carrot fly, which finds the carrots through their smell, which is then masked by the chives. Incorporating companion plants can help you to design square foot garden beds with beneficial mixtures of plants which can aid one another and create healthy, diverse eco-systems.
Companion planting is an inexact science and we know surprisingly little about how different plants interact with one another. That said, it is clear that plants with similar requirements will do well when grouped together.
For example, it is best not to place Mediterranean herbs, with their lower water requirements, next to especially thirsty plants that you will have to water often.
Similarly, it is easy to see how certain plants can help others by improving their environment. For example – taller plants used to provide mid-summer shade for neighbouring spinach or lettuce, helping reduce the risk that it will bolt in hot weather.
Some plants can help those in neighbouring squares by gathering nutrients. Dynamic accumulators such as peas and beans fix nitrogen from the air, while deep rooted plants like borage or yarrow can reach right down deep into the soil below your raised bed and bring nutrients back up. When leaves from these plants are used as a mulch around your crops, those nutrients are returned to the soil surface where they can then be taken up by neighbouring plants.
Build boxes and grids
There are lots of square foot garden kits on the market you can buy to make the frame of your raised beds, but you might consider keeping costs down by creating your own. Use reclaimed wood from old pallets or consider building a bed with bricks, old concrete blocks, stones or even logs from your garden.
Once you have assembled your frame, create a grid to demarcate each square foot. The easiest way to do this is by using string – see the video on this below. The grid is purely a visual tool (you do not need to divide the soil) to ensure you allocate exactly one square foot to each crop you choose to grow. You might also consider bamboo canes, straight branches pruned from garden trees or reclaimed plumbing pipes.
If required, lay your weed membrane or cardboard at this stage before you set down your frame in its permanent position.
Build box accessories
If you decided at stage 2 to grow climbing vegetables such as peas and runner beans, now is the time to create supports for them. Most climbing crops grow upwards by attaching their small tendrils onto a support network. Fine netting bought from the garden centre, or salvaged from a sea shore will do the perfect job. Attach the netting onto long bamboo sticks that are the appropriate height for your crop. Be sure to tuck any excess netting away so that birds and other wildlife do not get caught up in it.
While we are on the subject of wildlife and creating accessories for your square foot garden, it is important to know that wildlife will love the crops in your garden just as much – and probably more – than you do. Birds, rabbits and other insects such as slugs and butterflies can wreck havock in a kitchen garden, leaving you with a very depleted crop.
At this stage you might want to consider creating a physical barrier to protect your crop from birds, such as a wire frame to place around your brassicas (pigeons love brassicas the most), or thinking about slug deterring tactics such as sunken beer traps and copper piping.
Fill Your Square Foot Garden Bed
Once you have created your square foot garden frames and accessories, it is time to fill them with your growing medium. You may choose to follow Bartholomew’s book to the letter and use ‘Mel’s mix’ – a soil-free mix of peat moss, vermiculite and compost.
However, peat is not a sustainable source of material to use and the horticultural industry is doing a lot of work to eradicate its use in composts and plants. A more eco-friendly and sustainable suggestion is using a mixture of 50% peat free compost, together with 25% potting grit or fine gravel, and the final 25% fine chipped woodbark. The gravel and bark help to improve the drainage as well as water retention of the mix.
If you make your own garden compost from old raw vegetable scraps, grass clippings, chipped wood and cardboard, your crops will benefit from incorporating some of this into the mix too. If you don’t make your own garden compost, now is the perfect time to start! It is really easy, fantastic for your plants, and best of all it is absolutely free. Well-rotted horse manure is also a great addition to a veggie bed – it has to be well-rotted for at least a year, or else it may burn your crops.
Planting Your Square Foot Garden
Depending on where you live in the world, planting might involve sowing seeds directly into the soil, or, if you live in a colder part of the world, which experiences frosts well into the growing season, starting them indoors under glass might be a better option. In Scotland, we often get frosts well into May, and so the latter method is helpful to ensure you get crops a little quicker than you normally would by planting seeds directly into the soil. Watch the video on how to bring on seeds indoors here.
Whether you are planting seeds or seedlings, they key thing is to ensure you are placing the right number of each crop into each square foot of the garden. Here is a brief guide to the spacing requirements for some of the most common crops:
One Plant Per Square Foot
The largest plants that can easily be included in a square foot gardening system will require one whole square foot each. These include brassicas such as cabbage, broccoli, Brussels sprouts & cauliflower, tomatoes, peppers, aubergines and herbs such as coriander, rosemary, oregano, sage and mint.
Four Plants Per Square Foot
Some plants in this category could grow to full size if planted one per square foot, but can be more intensively planted if you harvest them as they grow, which will keep them in check.
These plants include Swiss chard, parsley, basil and a number of other leafy greens.
Nine Plants Per Square Foot
Crops in this category include peas, beetroot, large turnips, parsnips, kohlrabi and spinach. Each of your seeds or seedlings will be placed at four inches apart.
Sixteen Plants Per Square Foot
Carrots, radishes, onions, garlic and spring onions are all examples of plants that can be grown intensively at a spacing of 3 inches, in blocks of four by four.
Don’t forget about your companion plants – see section 2!
Maintaining your garden
Maintaining your square foot garden should be easy once you’ve got it growing – I promise it will be even easier if you have situated your garden in the right location – beside the house and a water source. The lack of space between plants means there are very few gaps for weeds to germinate – one of the huge pros of the square foot gardening method.
The key thing is to make sure your crops get enough water, all through the growing season. If you are planning a holiday in the middle of summer, you may have to recruit a friend or neighbour to come and water on your behalf. Bear in mind that overwatering is as detrimental as underwatering, so use your initiative here. If the soil is damp, it doesn’t need more water, but don’t allow it to dry out and get powdery – it will be hard to get it back from there if you do.
There is no need to feed your crops as we have used a compost mix that is rich in nutrients and natural food for your plants. If you have added garden compost or well-rotted horse manure then all the better. After that crop has been harvested, replenish the soil mixture in that square so that there are new nutrients for the next new plant.
The key to harvesting your beautiful crops is to do it at the right time. You don’t have to wait until the crop is at its biggest before you harvest – vegetables like carrots, peas, chard and beetroot can taste so much sweeter when they are harvested young.
Whether you are gardening for yourself or for family and friends too, harvest crops as close as you can to the time they will be eaten – a quick rinse under the tap and your journey from ‘field’ to plate can happen in minutes. Come summer, you might decide to pick and eat all the colours of the rainbow – choose what looks delicious, smells fresh and delights all of your senses in one go. Lots of crops, such as cut and come again lettuce varieties, will regrow after harvesting.
Others, such as root veg and brassicas, will need to be removed and you can move onto planting your next exciting crop. The key to succeeding with square foot gardening is to never have a square vacant at any one time – it’s a challenge but with enough research and motivation you can do it!
Any excess crops should be harvested and stored. Lots of veg will store well in the freezer, or why not turn your hand to creating chutneys and jams?
So, now you’ve got all the information you need to set up your new square foot garden, here’s a quick list of my five top dos and donts to keep you focused and on track with your new square foot hobbie.
Five dos and donts of Square Foot Gardening
- Give it a try! Square foot gardening is fun, cheap and efficient – you’ve got nothing to lose, and this could be the start of a whole new self-sufficiency journey
- Companion plant – using the right plant in the right place will deter pests and give you bountiful, beautifully pollinated crops. It’s far better to use natural solutions than harmful chemicals
- Grow crops that are hard to find in the shops – black runner beans, rainbow chard and purple carrots are some of my favourites
- Locate your frames where you will see them everyday. You will be able to see if you need to harvest, water or protect your crops from an unwanted pest
- Compost – create your own garden compost using old garden clippings, vegetable peel, grass clippings, shredded cardboard, tea bags and coffee granules. After a year it will be ready to use – it is the best food you can give your plants
- If you are new to growing, don’t try too much at once – start with one 16 foot frame and build more later
- Use peat or artificial fertilisers. Think about sustainability and your footprint on the earth. Peat free is best. Those horses are going to keep producing manure for a long time yet!
- If you live in Scotland or other northern climes, avoid trying to grow tender crops such as courgettes and tomatoes outdoors – they do far better in a polytunnel or greenhouse. Stick to tough plants like kale, onions, carrots and spinach
- Plant mint directly into your square foot bed – it will take over the whole space in no time. If you want to grow mint, do that in a pot and sink the entire pot into your square foot space to keep it contained
- Neglect climbing plants. Most will need help to find their way onto the support you have created for them. A wall or fence won’t do – they need a trellis or some netting to clamber up. Tie them in to help them on their journey.
Square foot gardening – the fool proof planting guide for beginners
If this is your first gardening venture, congratulations! I hope you get the bug for gardening and that the years ahead are full of lots of outdoor fun and adventures!
I want nothing more than to see you succeed. So here is my top list of crops for trying in your new square foot bed. These are all very straightforward to grow and guaranteed to bring you lots pleasure all year round.
- Peas – fresh from the pod these are the true taste of summer
- Dwarf runner beans – easy to grow and you won’t have to create a huge trellis or install a large net to support the dwarf varieties
- Brussels sprouts – nothing beats growing your own sprouts to put on the table for Christmas day
- Onions – a very versatile veg which is super easy to grow from sets, rather than seed. Protect from birds!
- Strawberries – the perfect way to teach little ones about where fruit and vegetables come from. Can be harvested and eaten on the spot
- Salad leaves – one of the most delicious and easy things you can grow. Rather than full lettuce heads which aren’t so easy to grow, try cut and come again varieties such as rocket, mizuna and lollo rosso.
- Beetroot – very quick to grow and comes in deep purple as well as golden yellow
- Parsley – a fantastic source of vitamin C and great for flavouring soups and salads
- Fennel (herb) – a gorgeous tall herb with aromatic and delicious frondy leaves. It will make any patch look beautiful
- Cosmos – an annual flower, perfect for cutting for the house and a real attraction for pollinators
- Leeks – a winter veg which can be left in the ground until it needs harvested
- Rainbow chard – what’s not to love about a plant that is easy to grow as well as being every colour of the rainbow?
- Heritage carrots – these ancient veg can be small and round or long and spindly. A fun deviation from the usual perfect orange root
- Nasturtiums – a pretty orange flower which is also edible – a pretty addition to summer salads
- Kale – my favourite is a variety called Cavolo Nero, wonderful for stir fries or oven-baked kale crisps
- Mint – apple mint, pineapple mint, strawberry mint – there are so many to choose from. Just make sure you sink it in a pot, or it will run riot through your whole plot.
The Pros & Cons of Square Foot Gardening
Like any gardening system, square foot gardening has both pros and cons. In order to determine whether square foot gardening (or some elements thereof) are right for you, it is important to examine these pros and cons in relation to your own garden, gardening style, preferences and requirements.
The pros of square foot gardening:
- Square foot gardening can give high yields in small spaces – far more food can be grown in this way than can be grown in a comparable space given over to traditional rows.
- Growing a variety of different crops close together is a form of companion planting, which increases biodiversity and helps to reduce the threat posed by pests and disease.
- Intensive planting minimises bare soil and acts like a cover crop to protect the important soil ecosystem that lies below.
- Closely planted crops also help to minimise the number of weeds that germinate and establish in the beds.
- The neat, raised beds of square foot gardening make it easier to garden if you are getting on in years or have mobility problems.
- The orderly nature of the system also makes it easier to stay on top of things and create a good plan for the whole of the gardening year.
- The raised beds and the garden system are easy to set up, even for complete beginners.
- The small beds are easier to cover with cloches, cages or cold frames to protect your plants than more sprawling and less intensively managed beds.
The cons of square foot gardening:
- The small beds are not ideal for crops that take up a lot of space such as pumpkins and squash, sweet corn or perennials like asparagus. (Though these can be grown elsewhere in your garden, leaving the square foot garden beds for annual vegetables with a more compact growing habit.)
- If placed above hardstanding rather than lawn or soil, 6 inch beds as suggested in Bartholomew’s 2006 book will be too shallow for the roots of many crops. (If raised beds are on a solid surface, they should be at least 12 inches deep.)
- The growing mix described in this book is, unfortunately, undesirable from a sustainability and eco-friendly point of view. Peat moss is not usually sourced sustainably, and vermiculite also comes at a high carbon cost. (Fortunately, greener alternative options for filling your square foot beds are available).
- Square foot beds (like all raised beds) require more water, as they will dry out more quickly than in in-ground growing growing areas.
- While fewer weeds develop in square foot gardens, those that do establish are harder and more time consuming to remove, as you will have to weed little and often, by hand, rather than going between traditional rows with a hoe.
It is important to remember, when setting up a new growing area in your garden, that you do not need to follow one system religiously. While there are many things to recommend a square foot garden, it may not be right for you.
Some elements of the system may work for you while others need to be changed or adjusted to suit your individual needs. Be open to altering the ideas as you learn and garden, and you will end up with a garden that is best suited to you.
I do hope you’ve enjoyed learning a thing or two about square foot gardening. For more information, check out the Square Foot Gardening Foundation website
And if you know someone who might enjoy owning a square foot of land in Scotland, then our project would love your support.