Have you got that deep, fertile, well-drained soil that never dries out? Do you have soil that warms up quickly in spring and retains moisture, even in periods of drought? Soil that you can get on to dig, cultivate and sow after a long wet spell? Well, if you have, you are one of very few. That is why more and more gardeners, that are serious about vegetable growing, are considering and installing raised beds.
A raised bed gives you the advantage of soil depth and good drainage, which means you can grow more in a small space. With good soil depth and fertility you can plant many crops closer together without loss of yield due to competition for water and nutrients. Also, because your vegetables will be easy to access, in many case you can broadcast sow, rather than sowing in rows. You will be growing over the whole soil area of the raised bed, rather than growing in rows. There is no need to leave space to move and cultivate between the plants.
So often I hear gardeners bemoaning their heavy clay soil; it’s heavy to dig, wet in winter and like rock in summer. It takes ages to warm up in spring delaying your start at the beginning of the season, especially if the weather is cold, as it has been in many places this spring. The soil or compost in a raised bed warms up more quickly and the excellent drainage means that you are never prevented from working on it due to poor weather conditions. You have control over what you fill your raised bed with, so there’s no excuse: you can have great soil.
This is a particular advantage to those attempting to garden in plots attached to new-build properties. The soil is invariably compacted and full of rubble and a raised bed offers welcome refuge for your precious crops.
So what do you fill your raised bed with? To a certain extent it depends whether you site your raised bed on a soil base or a concrete or paving solid base. If it’s going on paving or concrete you need to fill it as if it were a patio container: with specially formulated compost. As I said last week, garden soil can be a real problem in the confines of a pot. I would use a mixture of multi-purpose compost and loam-based potting compost.
If it’s going on a soil base, for example on the vegetable plot, you can use garden soil. Either good quality top soil or your own garden soil if it’s reasonably good, but can be improved. It is really important that it is free from perennial weeds and free from stones if you intend to grow root crops. I would mix this soil with good garden compost or up to fifty percent multi-purpose compost to improve its structure. The different between the solid base and the soil base is that instead of creating a large container you are just raising the soil surface and increasing the soil depth. Its really important to cultivate the ground below the raised bed thoroughly before you install it; you want your crops roots to go right down into the ground below.
Most vegetables grow best on a slightly alkaline soil rather than a neutral or acid one. That’s why traditionally we apply lime in the autumn to raise the pH and create the ideal growing conditions. Of course you have more control over the soil pH in a raised bed from the outset.
If you have space, a number of raised beds will make managing a crop rotation really easy. Personally I find it quite difficult to remember which bit of my veg. patch various things grew on the previous year. I can usually just about remember where the potatoes were, but beyond that it’s a mystery.
The ideal would be to have four raised beds:
The following spring you are back to the beginning and plant potatoes again. This achieves ideal crop rotation across four raised beds.
It is of course always easier to protect your crops in a raised bed from insect pests, hungry birds and rabbits and from the vagaries of the weather. At the end of each season a raised bed is easily refreshed with fresh soil or compost. Your crops will always be that bit closer to you too so thee is less bending, which has to be good news.
You could make your own, or you could buy one of these great kits:
On a solid base the ideal depth for a raised bed is at least 30cm (1ft) deep. On a soil base 20cm (8ins) deep is enough if there is good soil beneath. You could make your own, but there are some very handy, easy to use kits available from Gardman. These sectional raised beds just snap together, so you can build your new vegetable production unit quickly and easily.
If you are using them on paving or concrete they come with a black polypropylene liner which prevents the compost from washing away when you water. This is really important; you may be surprised just how much of your valuable growing medium escapes through the gap between the bed and the patio.
They are also made just the right size to fit a handy, high raised bed cover. This is easily ventilated and closed at night; ideal at the beginning of the season when your valuable crops may still need a little protection.
If you are still a little sceptical I recommend that you try one or two of the Gardman raised bed kits this season and just see what a difference growing your veggies in this way makes. Less bending, no digging and your vegetables will be more prolific – so go on, raise them up where they belong!