Before doing anything, you must get to know your soil, whether it is acid or alkaline and its make-up. The results will govern which plants will naturally thrive and how you can improve the soil to successfully grow these and other plants.
So your first purchase should be a pH kit, then refer to this list of the five main soil types with advice on how to overhaul their structure.
Clay: The main problem with clay is drainage, as a result it should be nutrient rich but hard to work. Dig over in the autumn, introducing organic matter, and let the weather do its work. Lime will improve drainage, but you must balance the amount you use with what you want to grow. If it’s very heavy, work in course grit, you can also use raise beds to help the soil both dry out and warm up.
Sand: Easy to work, but any nutrients are easily drained, so large amounts of organic matter can increase its water retentiveness and additional fertilizer can be used to replace nutrient deficiency. Try to mulch as much as you can and cover the soil with lots of vegetation all year round to minimize nutrient loss. If you are growing vegetables, sow green manure, when this is dug in it will add nutrients and improve the soil structure.
Silt: With a structure similar to clay, the biggest problem is drainage. It’s unwise to to walk on this type of earth when it is wet as you will only compact it even more. Dig it over in the autumn so that frost can help to break it down, introduce coarse grit and organic matter and use raised beds to warm up and dry out the soil.
Chalk: This, similar to sand, is a free draining soil from which nutrients can easily be leached. It’s also very alkaline. Digging in the autumn is not really necessary, leave that to the spring before you sow anything, and as there’s probably not a lot of top soil, don’t dig too deep. Add organic matter to increase acidity and aid drainage. Make sure that the ground has a good covering of vegetation throughout the year, including green manure in the winter and mulch with peat, grass cuttings and manure.
Peat: This type of soil has a tendency to be acid so use lime to balance the pH especially for vegetables and fruit. Peat is made up of decomposed vegetation so there is no need to dig or add any organic matter, but you may have to use an organic fertilizer to combat any nutrient deficiency.
Soil Over Time
When creating a vegetable bed you will realise that organic matter, whether it’s compost or manure, has a big part to play in improving soil. Return it to the earth by digging in over the autumn and using it as a spring mulch. As well as feeding the soil with nutrients, it will improve drainage in heavy soils and increase the water holding capacity of light soil.
Alternative soil conditioners can be used such as mushroom compost, wool shoddy, seaweed, composted pine bark, spent hops and peat. What you use and how much will depend on your soil’s analysis and the plants you wish to grow. For example mushroom compost is slightly alkaline so will be good for acid soil, pine bark has no nutrients so is best used as a mulch, while seaweed is particularly rich in trace elements.
Soil matures over a number of years, don’t expect a quick fix. Organic matter and conditioners used conjunction with good management, such as crop rotation, do increase productivity, particularly If you take the time to analyse exactly what type of soil you have and therefore what it needs.
Building A Raised Bed
Growing vegetables in a raised bed has many advantages over a traditional plot and they can be quickly and easily created.
To construct a raised bed for vegetables, you’ll need two boards measuring about 1in x 4ins x 4ft long and two others of the same thickness and height but as long as you like, 6ft or 8ft would be a good choice.
Nail or screw 12in pegs near the end, and flush with the top, of each board. With the pegs facing inward, use a mallet to drive them into the ground, so the boards form a rectangle. A long spirit level is useful to ensure that they are level.
Now fill the bed with well rotted manure, compost and top soil.
If you're unsure about constructing one yourself, several manufacturers have easy to assemble raised beds made from excellent quality timber.
Are Raised Beds More Productive?
First impressions of a plot using raised beds for vegetables are good. Growing areas are physically separated from paths and everything looks very neat and orderly.
The theory is that, as the bed is deep and the soil not compacted, the roots have lots of room to grow downwards.
Hence vegetables can been sown in blocks instead of rows and grown closer together, significantly increasing yield.
Easy access is also guaranteed since the bed is only 4ft across and can be tended from either side. As you don’t tread on a raised bed, the free draining soil structure should be maintained and only a little forking before planting is required.
You can also control in a much more effective way the soil’s pH. Most vegetables prefer neutral to acidic growing conditions. So if you have naturally alkaline soil, by raising the bed you can create a more acidic environment.
As for maintenance, add a layer of compost or manure every spring and mulch to discourage weeds. A crop of green manure at the end of the season would be useful.
Are There Any Negatives?
There are only a few drawbacks. If you buy the boards, there is the initial expense and effort in creating the beds. You may need a friend to help with the work.
Since the soil should have good drainage, extra watering may be necessary especially for seedlings and young crops.
Not all vegetables can be successfully cultivated. For example, potatoes need earthing up and staking runner beans in soft soil isn’t satisfactory.
However, when all these factors are considered, raised beds certainly do make sense. Increased productivity will soon outweigh the initial expenditure and, unless you enjoy digging, they are very much a labour saving idea.