Why use raised beds in the vegetable garden?
I guess the best place to get started is why should I grow in Raised Vegetable Beds in the first place? There are a number of good reasons which I'll illustrate below but in general it's all about creating a deep nutrient rich soil which, crucially, doesn't get walked on or compacted. The good open soil structure present in raised beds makes root growth easier for plants as well as containing air pockets for beneficial microbial life and other friendly organisms. Remember it is the life living in the soil that feeds your plants rather than the soil itself; these beneficial bacteria need oxygen to survive so a good open soil structure is essential. Soil is the key to successful raised beds growing systems (or any gardening) and keeping your planting in dedicated protected spaces allows you to pamper this essential resource.
Here's why I think raised beds for vegetable gardening makes sense:
- Protect your soil from traffic, this ensures the soil doesn't get compacted by walking on the soil. An open, oxygenated soil supports important soil life and makes it easier for plant roots to penetrate.
- Choose your soil. Many gardens have shallow soil of poor quality which won't be sufficient to feed demanding vegetable plants. A greater depth of quality soil means a larger root and a healthier plant.
- Grow successful carrots and other root crops. Carrots are very difficult to grow in a heavy clay soil and will be stunted or forked in appearance. Raised beds allow you to create the soil you want depending on what you are growing. You can mix in extra compost, sand or manure when filling your beds to create the perfect growing medium.
- Raised Beds are easier to manage. You'll have less trouble with encroaching weeds from the surrounding area. The extra height makes weeding a raised garden bed much more comfortable as bending is reduced. We supply a wide range of raised planter heights including 2 tier beds and beds with a bench seat included.
- Protect from garden pests. We supply mini polytunnel systems to fit our raised bed range which can be covered with a micromesh insect barrier to exclude carrot and cabbage root fly and cabbage white butterflies.
- Raised Planters are Neat and Tidy. If you're growing in your back garden you don't want to ruin your view with an untidy plot. Raised vegetable beds create a neat, easy to manage growing area.
- Warm Quicker in Spring. Raised beds will warm quicker than the surrounding soil in Springtime from the heat of the sun on the sides. This allows you to get going a little earlier as growing depends more on soil temperature than outside air temperature. We also supply mini tunnel kits that can be used with a polythene cover to make a mini growhouse for early Spring growing or cultivating warm climate crops in exposed gardens.
- Raised Beds Aid Growth. The rich deep soil means you will get more vigorous growth from your vegetable plants and in many cases can plant at closer spacings making a small area more productive. Raised beds are particularly useful in an urban vegetable garden where space is at a premium.
How to Build a Raised Garden
Raised bed gardens are just containers for soil which can be built to any size to suit the space you have available. Keep in mind that the smaller the amount of soil in the bed the quicker it will dry out so a large bed is better than a small one if you have the room. It is better to place beds on grass or soil to make make the most of soil depth and moisture but raised planters of sufficient height can be placed on a hard surface
Beds can be built from brick or stone but we like to use timber as it is quick and easy and looks great when planted up. We supply a broad range of treated timber raised bed kits but you can also make your own with waste timber if you wish. The advantage of treated timber for vegetable beds is that it has a life of between 10 and 15 years depending on the thickness of the wood. Untreated waste timber will probably last 2-3 years.
Building large raised beds using planks and timber stakes
One of the easiest ways to build raised vegetable beds is to use planks of wood and timber stakes for support. This method is particularly good if you are using more than 8ft lengths of timber to create beds. This is the method I have used in my own garden where I have grid of 20ft beds intersected by gravel pathways.
Create your beds by dividing up your plot with gardening twine and sticks to mark the location of your raised beds and your paths. I would recommend your beds shouldn't be wider than 4ft as anything wider makes it difficult to reach the middle of the bed. Your paths should be a comfortable width for a wheelbarrow while not taking up too much of the available growing space, I would suggest 3ft is about right. You can see my paths in the picture between my raised beds (which I made a little too wide!) before I put the weed control fabric and gravel down and can see the 9 inches of soil flanked by the timber sides.
To make your new raised beds simply shovel the soil from the path area into the centre of the bed area. Make sure you do your digging and earth moving when the soil is reasonably dry as soil structure is damaged by working wet ground.
Hammer timber stakes or rebar (rebar is short for reinforcement bar, they are lengths of steel bar, ask in your builders supplier) along your string line ensuring at least a third is buried in the ground.
Lean the timber raised bed boards against the inside of the supports and pull the soil up against them to hold them in place. There is no need to fix the boards to the supports as the weight of soil in the bed is pushing the planks firmly against the posts. To keep weeds in the pathways under control I have also added a layer of 'Mypex' weed control fabric covered in pea gravel in my garden which keeps the garden looking tidy and makes it much easier to manage.
Simple plans for wooden planters
As we've said raised beds are simply large boxes made to contain your garden soil. If your beds are to be placed on grass or soil there is no need to build a base for your unit; it is actually beneficial not to have a base as the soil below acts as a moisture reservoir and earthworms and other beneficial soil life can enter your beds from below. If your beds are to built on a hard surface like concrete or patio slabs use a sheet of Mypex weed control fabric to line the bed. The 'Mypex' is semi permeable so will allow excess water to seep out while preventing soil particles from escaping around the base of the bed.
We use 2 main designs for our Quickcrop wooden vegetable planters, I include one of the basic plans below to show you how we make our most popular beds. You can either buy ready cut raised bed kits from us or source your own timber and use the plans to make them yourself.
The quality of our beds is in the timber which is cut and planed before we treat it to ensure every surface is treated with our vegetable safe preservative. Remember if your are buying treated timber make sure the preservative used is arsenic free and that any cuts you make are treated afterwards to prevent the ends from rotting.
Classic Allotment Style Planters and Premier Raised Garden Beds
We use the same design for our Classic Allotment Planters and our Premier Garden Beds. The Premier bed uses thicker timber which reduces the chance or warping while the cheaper Classic bed is a value alternative where looks aren't so important.
Our wooden planters come in a range of sizes, the popular being 6ft x 4ft. If your beds are to be longer than 8 ft we recommend using a cross brace in the middle of the bed to prevent the weight of soil inside from forcing the bed to bow. A cross brace is simply another end panel screwed into the centre of the planter separating it in two.
How to build a 6ft x 4ft x 14 inch high raised bed
In this case we are building a 14 inch high bed which is suitable for a broad range of deep and shallow root vegetable crops. Your beds can be any height, simply adjust the number of boards and height of corner posts accordingly.
You will need:
4no. 3in x 3in x 14in high corner posts. 4no. 6ft x 7in high planks (we recommend a thickness of inch and a quarter). 4no. 4ft x 7in high planks. 32 no. 4x50 self tapping wood screws.
Step 1: Take 2 of your 4 ft lengths and place them face down on the ground. Take 2 corner posts and place them under each end as if you were making a miniature coffee table as shown in the illustration. Make sure the posts are aligned neatly with the edges of the boards and fix using 2 screws per plank. Avoid screwing too close to the edge of the plank to give a stronger fix and to avoid the timber splitting.
Repeat the process for the other 4 ft lengths so you have two identical ends.
Step 2: Stand one of the ends of the bed up and fix the long 6 ft planks to the corner posts. If the site you are working on is uneven it helps to use one of the 6ft planks as a base to make sure the bottom board is square and to the right height. Once the bottom board is correctly fixed the next one is easily positioned on top. Screw your fixing in to the the corner posts rather than the ends of the 4 ft boards as this gives a better fixing.
Step 3: Repeat step 2 until you have all 4 corners completed. The reason we fix the raised bed ends inside the long side planks is if you are building a long bed another end piece of the same size can be used to brace the middle of the vegetable bed.
The bed is strong enough at this stage to move around the garden by lifting the end and dragging it to the desired spot.
Cheap Raised Garden Beds
Vegetable beds can be made from any material but the cheapest and easiest way build a raised bed is to use free waste timber.
Be careful not to use timber which has a chemical treatment or a lot of paint as these can contain lead which can end up in your soil, your plants and then in you! Similarly old railway sleepers aren't a good idea as they are soaked in creosote which won't do you much good either.
What height raised bed do I need? You have a couple of questions to answer before you decide which height raised bed is best for you. Considerations would include the cost of the raised beds, the condition of the soil under the bed, the depth of soil needed for what you want to grow and creating a comfortable height.
If your raised bed is being placed on a hard surface like a concrete patio area you will need a deep bed to give you sufficient depth of soil for your vegetables to grow. Also be aware that a shallow bed on a hard surface will dry out very quickly as there is no moisture being drawn up from the soil below. If your bed is being placed on soil you need to decide if the soil quality in your garden is good or bad. As a rule of thumb any soil with a high percentage of organic matter will be good for growing vegetables. The darker the colour of the soil the more organic matter it contains so you should get a pretty good idea by digging a test hole. If your soil quality is poor you will need a bed of at least 14 inches high to grow most vegetable crops successfully.
What vegetables do I want to grow in my raised garden beds?
Some vegetables need deeper soil than other so it's worth looking at what you want to grow before deciding which bed to choose. For example lettuce plants will thrive on a well fed shallow soil whereas deep root vegetable like carrots, parsnips or potatoes clearly won't. Take a look at the handy table below to give you an idea of how deep the roots these common vegetables grow.
Shallow Root 12 t0 18 inches - Broccoli, Brussels Sprouts, Cabbage, Cauliflower, Celery, Chinese Cabbage, Endive, Garlic, Kohl Rabi, Leeks, Lettuce, Onions, Potato, Radish, Spinach.
Medium Root 18 t0 24 inches - Broad Beans, French Beans, Runner Beans, Beetroot, Carrots, Chard, Cucumber, Aubergine, Kale, Peas, Peppers, Summer Squash, Turnips, Melon.
Deep Root 24 t0 36+ inches - Artichoke (Jerusalem), Asparagus, Parsnips, Pumpkin, Rhubarb, Winter Squash, Sweet Potato, Tomatoes.
Square foot planting plans for raised beds.
The Square Foot gardening system was built around raised beds and is an ideal solution for beginners or gardeners with a relatively small growing area. The idea behind the system is the bed is split into a grid of square foot (30cm) sections with a fixed number of each crop occupying each section. Square foot gardening is an ideal fit for our raised planters as we stick to standard sizes of 4ft x 4ft, 6ft x 3ft, 6ft x 4ft and 6ft x 6ft, all of which a divisible into a square foot grid.
The reason square foot growing in raised beds is so handy for beginners is it quickly shows the planting distances for each crop. One of the biggest problems novice vegetable growers have are the planting distances of the various crops. In the traditional system we have a distance between plants and a distance between rows which can make it difficult to plan a garden, especially in a small space. The fact that square foot gardening revolves around a fixed measurement of one square foot makes the system very easy to use, all you need to know is how many plants fit in that square.
A typical Square Foot Garden uses timber raised beds 7-14 inches high (depending on the surface under the bed) and 6ft x 4ft in size. The 6x4 bed is then subdivided using string or timber laths to form a grid of 24 squares.
Each square is filled with with the plants of your choice according to the recommended numbers for each square foot. Some plants need more than a sqaure foot of space (like the potatoes in the sample above) and will take up multiple squares. You can see the large potato square takes up 4 square feet with 2 plants growing in each space. We provide a planting key with each plan to show the planting layout for each crop, it may look a little confusing now but it is very simple once you get going.
We have a number of sample square foot garden plans on our site which have been designed to fit our raised beds. You can view our square foot garden plans by clicking the link.
What is a comfortable working height for me? Many of us have difficulty bending which is where growing in a raised garden bed really makes sense. You can build a bed to any height you wish but for most people even a modest 14 inch high bed will make maintaining their garden much more comfortable.
Be aware that the higher the bed, the more soil will be needed to fill it. A 21 inch high 6ft by 4ft bed will take just under a cubic metre (1 tonne) of soil to fill so make sure this is taken into account when making your decision.
If a higher bed is required there are also easy access options like the Vegtrug range of beds and our Quickcrop Raised Vegi-table.
The Vegi-table style beds will have a more shallow soil than those placed directly on to the ground so are more suitable for shallow root crops like herbs and salad or leafy crops like spinach or chard. Easy access beds are perfect for wheelchair users or gardeners with restricted mobility.
The Vegtrug (pictured above) is a global success with growers locates all over the World. It is an easy to assemble kit that produces a very strong and good looking fruit and vegetable planter. We supply a range of Vegtrug kits including tailor made fleece, mesh and polythene covers for protecting against pests or harsh weather.
Where to buy a raised garden bed kit?
From us! We have a range of beds from our budget 'Classic Bed' to our 'Deluxe' top of the range vegetable bed with rounded corner posts and galvanised brackets. New this year we also have our timber 'Easy Assemble' beds which don't require any tools or fixings - they simply slot together. We also have a broad range of raised garden bed supplies including topsoil, compost, vegetable seedling plants and all the consumables you'll need to grow a fantastic crop.
All our beds use Pressure treated timber meaning the timber will last a minimum of 15 years of harsh outdoor conditions. The preservative used has been certified by the soil association as safe for use with organic food crops so you can be sure no harmful materials enter the soil.
Our raised vegetable beds come in a range of heights from 7 inches through to 9, 14 and 21 inches tall. The beds also come in a range of sizes including 3 x 3ft, 4 x 4ft, 6 x3 ft, 6 x 4ft and a whopping 6 x 6ft bed. We also cur custom lengths of timber should you require a size we don't stock.
To view our range of Quickcrop timber raised vegetable beds please click on the link below to open our full raised bed shop:
More information on our raised vegetable beds can be found at the link.