Soil Types at the Allotment

When we are thinking about planting seeds and plants out on the allotment plot, we first prepare our soil, adding compost, manure and other organic matter to improve it and provide more nutrients for a better crop. The more experienced grower will tend to know what type of soil they have and depending on the soil type will depend on what is needed to treat it and for which crop. But it does not mean it is a minefield!  

There are six main soil types in the UK: 

Clay 
Sandy 
Silty 
Peaty 
Chalky 
Loamy  

So, how do you know, which soil type you are likely to have? 

Wet Clay soil is very sticky and lumpy  
When clay soil is dry it is rock hard 
Clay soil poorly drains 
Fewer air pockets 
Slower to warm up in Spring 
Cultivation is heavy going 
Holds more nutrients than other soils and therefore will produce good crops if the clay soil drainage is improved  

Frosts and cold winters help dug over soil breakdown and before planting in Spring, ensure your planting area is broken down further directly around the plant with no gaps for waterlogging. It is advisable to work in some good compost and mulch the beds too. 

Sandy soil is freely draining 
It feels gritty  
Quicker to warm up in Spring 
Easy to cultivate 
Dries out quickly 

It can lack nutrients with this free-draining soil, quick drying soil. 
Sandy soil will require a lot of regular watering and feeding but can produce a good crop with some TLC. Add generous amounts of compost and organic matter regularly and your soil may even need watering during dry spells in the winter. 

Silty soil is smooth and soapy to handle 
Holds moisture well 
Richer in nutrients  
Easier to cultivate than clay but is 
Heavier than sand 
Soil structure is easily compacted and is weak 
A very good soil if well managed 

Silty soil is very fertile and will require less help from other added nutrients from compost but that's not to say you can still treat it for your crops. 

Peaty soil contains a much higher level of organic matter/peat because the soil’s acidic manner limits decomposition 
Fewer nutrients 
The colour is darker 
Warms up quicker in Spring 
Holds water and will require drainage 
Fantastic for plant growth if fertiliser is added 

Drainage such as peat moss can help retain the water along with other organic matter for nutrients.  Peat moss alone will not aide your soil very well. Peaty soil is not commonly found in gardens. 

Chalky soil is alkaline, with a pH of 7.5 or more 
Very stony 
Free draining, becoming very dry quickly 
Often over chalk or limestone rock 
This means some minerals, such as manganese and iron become unavailable to plants, causing poor growth and yellowing of leaves 
This can be cured by adding fertilisers 

Chalky soil can be treated with organic matter to improve the humus levels and moisture, on a very regular basis. Green manure will help provide nitrogen for vegetable growing. 

Loamy soil is the most ideal soil! 
Good structure 
Drains well 
Retains moisture 
Full of nutrients 
Easy to cultivate 
Warms up quickly in spring and doesn’t dry out in summer 

If you find that you have loamy soil, you have struck gold as a grower! To achieve this great balance if you have other soils, is to keep adding the compost and organic matter as well as mulching methods. 

Shallow rooted vegetables such as lettuce, beans, chard, sprouts and cabbages like clay soil. 
Carrots, potatoes, cucumbers and radishes like sandy soil. 
Most fruit and vegetables will grow well in silty soil. 
Brassicas, legumes, salad crops and root vegetables do well in peaty soil. 
Spinach, beetroot, sweetcorn, cabbage and grape vines will grow well in chalky soil. 
Most crops will grow well in loamy soil. 

In summary and as common sense prevails, a good soil will provide a good balance of water retention and drainage, air flow and nutrients to grow a good crop with added help with the right compounds if, and when it is required. 

Have you seen our Composting page?