Know Your Garden’s Soil Type – and How to Make the Most of ItColin Campbell-Preston
Good soil is the cornerstone of any successful gardening project, providing the nutrients and drainage your plants will need to thrive. From the pH balance to the way it retains moisture, there can be plenty of reasons why your soil type is making it difficult for your garden to perform at its best. But if you’re new to gardening and don’t know what soil type you have, never mind how to make it better, what can you do about it?
Don’t worry, we’ve got your back! We’ve put together this handy soil guide so you can recognise different soil types (and you don’t have to admit you don’t know which is which) and details what you can do to improve them. From picking plants that love your soil to adding compost to make it more welcoming, there are plenty of ways to make your garden thrive no matter what its soil type.
If your soil feels sticky when wet and can be rolled into a ball, but is hard as a rock when it’s dry then you’ve got yourself a clay soil garden. The good news is that clay is made up of small particles, so it has good water storage properties. It is also very rich in nutrients, so as long as you know how to take care of plants in clay soil you’re likely to find that your garden thrives. Clay soil warms up slowly in the spring, so is better suited to summer vegetables and other plants that bloom in the warmer months. You may also find that you have to enhance the drainage of clay soil to create more airspace and prevent the plants from becoming waterlogged. Fruit trees, perennials and shrubs all thrive in the rich environment of clay soil.
If you have a garden that dries out quickly and feels gritty underfoot, it is likely that you have sandy soil. This soil is easy to cultivate due to its light texture and it warms up fast in the spring, but this lightness also means that nutrients are quickly washed away. You’ll need to use a fertiliser to give your plants everything they need and you might also need to use mulch to help with water retention. Bulbs like tulips will thrive in sandy soil, as will a lot of root vegetable crops. Things like lettuce, strawberries, tomatoes and courgettes are often grown commercially in sandy soil, so you’ll have plenty of choice for plants that will thrive.
A soft, soapy feeling garden that holds a lot of moisture is described as having silty soil. This soil type is very nutrient dense and the soft texture makes it easy to cultivate, so it is ideal for a variety of plants. One issue you will need to be aware of is the need to create drainage, as this soil tends to be very moist which can affect your plants. You can do this by mixing in composed organic matter to improve the structure and allow water to drain off more easily. Shrubs, climbing plants and grasses will all thrive in your silty garden, as will moisture-loving trees such as willow, birch and cypress. Most fruits and vegetables will be happy in silty soil, but adequate drainage must be ensured if you want an abundant crop.
Peaty is a slightly trickier soil type which can be identified by its damp, spongey texture. It is an acidic soil type, which causes the soil to have fewer nutrients than more pH balanced soil types. Although the soil heats up quickly in the spring, it does retain a lot of moisture, and drainage channels are often the best way to ensure your plants will thrive in soil with high peat levels. If it is blended with rich organic matter, many plants will do just fine in peaty soil. Shrubs such as heather and witch hazel do particularly well, as do vegetable crops like brassicas and legumes.
Chalky soil tends to be large grained and stony, with a chalk or limestone bedrock underneath. This soil type drains freely due to its loose texture and often has an alkaline pH that can stunt plant growth. For successful planting in this type of soil, it is best to add a fertiliser and humus to the soil to improve water and nutrient retention. Trees, bulbs, and shrubs do well in chalky soil, particularly things like lilacs, pinks, and Madonna lilies. If you were hoping for some edibles – cabbage, beetroot, and spinach are all suited to this soil type.
Loamy soil is the holy grail of soil types, with an even mix of sand, silt and clay making a fine textured, slightly damp soil. The soil’s structure means it drains well without losing essential nutrients, can be easily cultivated due to its loose texture, and warms up quickly in spring without drying out in the summer. Although loamy soils do often require frequent replenishment with organic compost to maintain nutrients and combat their tendency towards an acidic pH, this soil type is suited to growing a wide range of plants. Climbers, shrubs, perennials, and most berry and vegetable crops will thrive in this soil.
Improving London Soils
Soil in London tends to be either chalky or clay based, which each have their own problem when it comes to creating a garden that thrives. For both types of soil, a great place to start is by mixing organic matter into the soil. If you have chalky soil this will help replenish nutrients and slow the water run off that is often a problem with this type of soil. If your soil us more clay based, adding organic matter will stop it from being too dense to dig over and help water to flow more freely through it. Another great option for difficult London soils, especially if you have limited time to spend in the garden, is to create raised beds with a loamy soil, so you can grow a wide variety of plants easily.
If you find that your plants seem to struggle in your garden or tend to turn yellow in colour, the first thing to check is your soil’s PH level. PH is the unit used to measure the acidity or alkalinity of a substance, both of which can affect how things grow in your soil. Soils usually range from a very acidic PH of 3 to a very alkaline PH of 10, with a PH of 7 being neutral. Most plants enjoy a slightly acidic soil of around PH 6.5. Soil PH can have far reaching effects on your plants, with yellowing, brown flecked or dead leaves suggesting that your soil may be too acidic or alkaline, leading to nutrient deficiency and even plant poisoning. You can usually test your soil’s PH with a home kit and use limestone to raise the PH and sulphur to lower it in most cases.
For everything you need to treat your soil this year, why not pop down to one of Capital Gardens’ three store locations – each one is full of our helpful Plant People who know a thing or two about preparing their back garden for perfect growing conditions.