Soil is a more complex material than it first seems. Made of organic matter and mineral particles of different sizes. How these particles are connected to each other defines the makeup of the soil. A slightly different property than the soil structure which can be altered. The type of soil you have is largely what you will have to deal with although you can improve it in most instances.
Soil Types & Soil Structure
The soil particles create the conditions you will have to deal with, for example, in sandy soil, these particles are fairly large, weakly held to each other, so the soil is porous. On the other hand, particles in the clay soil are small and held to each other strongly, forming a denser and more water-retentive medium.
How much water soil retains, how rapidly it dries out, and what amount of nutrients it holds, is all determined by the structure of the soil as well as the soil particles. Well-structured soil is broken into separate crumbs, with half the pores filled with water and half with air. The air and water circulate in the pores around these crumbs, providing a plant with vital nutrients.
What Type Of Soil Do You Have?
Understanding your soil type and its properties help you to determine what kind of plants will do well in your garden and what amendments your soil may need.
There are six main types of soil:
It should be noted, of course, that all soil is made up of a composition of all variety of particles although it may be heavier in one particular type.
If you have this type of soil, then you’re a lucky gardener. Loam is the easiest type of soil to work with and has a very good, loose structure. It is mostly made of equal parts of clay, sand, and silt, so it drains very well but it holds moisture at the same time.
Good soil holds its shape when squeezed, but it crumbles under pressure – and that’s what happens with the loam when squeezed. Loamy soil has a great structure for planting and it’s easy to cultivate and work with. It also holds nutrients fairly well.
How to Improve Loamy Soil
Although loamy soil is the best year-round soil for gardening, it occasionally needs to be balanced with fertilizers or organic matter such as compost or mulch. Loamy soil tends to be slightly acidic, but you can always bring into balance by using simple additives.
Plants for Loamy Soil
Loam is suitable for growing a wide selection of plant varieties, except for cacti and other succulents that are used to dry conditions.
Sandy soil is considered as one of the poorest types of soil, but knowing its pros and cons can help you get the most from it. Sandy soil is light and it’s comprised of small particles of weathered rock such as granite or limestone. It is a gritty, rough and coarse type of soil.
Sandy soil drains quickly due to its porosity, but it also loses nutrients rapidly. Since vital nutrients are quickly washed in sandy soils, the soil usually requires regular fertilization. However, this type of soil is easily cultivated and warms up quickly in the spring, so it’s perfect for seedlings.
How to Improve Sandy Soil
Sandy soil has very low nutrient content and it isn’t fertile as other types of soil. In order to improve this type of soil, you should regularly apply organic matter such as manure, tree bark, garden compost, leaf mould, etc.
The addition of organic material will help retain moisture as well as help to maintain nutrients.
Plants for Sandy Soil
This type of soil is perfect for plants that prefer good drainage and rather dry conditions. This includes many glaucous flowering plants, Mediterranea herbs, shrubs and trees such as desert cacti, Sempervivum, certain Sedum varieties, Lavender, Cosmos, Rosemary, Plox, Foxglove, Zinnia, Erica, Calluna, and many more.
Another type of soil that brings a lot of frustration to gardeners is clay soil. Clay soil is easily distinguished – it’s lumpy when you hold it, it’s sticky when it’s wet, and it cracks when dried.
The mineral particles in clay soil are the smallest (their average diameter is less than 0.002 mm), with tiny spaces between them. These spaces or pores within clay soil are filled with water, rather than air. This means that clay soil holds a high proportion of water and it’s difficult to drain.
Poor drainage is the major con of clay soil. Clay soil drains slowly, it easily gets waterlogged, and its density doesn’t leave much space for plant roots. Due to its density, clay soil is heavy to dig and cultivate.
How to Improve Clay Soil
By adding organic matter you can break the dense structure of clay soil. Organic amendments will increase the airflow and improve the drainage. You can use manure, grass clippings, shredded leaves, coarse grit, compost or other types of organic material.
If you manage to improve the drainage of clay soil, you will have good, fertile soil with lots of nutrients. Improving clay soil takes time so don’t expect quick, overnight results.
Plants for Clay Soil
Various fruit trees, ornamental trees, shrubs (Spiraea, Weigela, Cotinus, Aralia…), perennials such as Aster, Astilbe, Hosta, Polygonum, or Helen’s flower; climbers such as Wisteria, Campsis, Passiflora etc.
Silty soil, comprised mainly of intermediate-sized particles, is soft and smooth, with a soapy, slippery texture. This fine, sediment material is mainly found near rivers, lakes, and other water bodies, but pure silt soils are quite rare.
Silt is made up of rock and mineral particles smaller than sand but larger than clay. Both sandy and silty soils have only small amounts of clay particles, so both types are fairly well-drained. Silty soil holds water slightly better than sandy soil.
This type of soil is fertile and rich in nutrients, but it easily gets compacted. If well managed, silt is a very good soil for growing plants.
How to Improve Silt Soil
As mentioned, silty soil’s greatest weakness is the tendency to become compacted and form a crust. It easily becomes waterlogged, so avoid overwatering.
To improve the structure of silty soil, you can amend it with organic matter like compost, decayed sawdust, wood clippings, etc.
Plants for Silty Soil
Choose plants that can withstand ‘wet feet’ – Irises, New Zealand flax, Lysichiton, Butomus, Caltha, Pontederia, Ranunculus flammula, Gunnera manicata, etc. Trees and shrubs such as weeping willow, American elder, bald cypress, river birch, and red chokeberry love silty soil.
Peaty soil has a distinctive dark brown, almost black colour; it’s usually damp and it feels spongy. Peaty soil contains a much higher proportion of organic matter and it’s pretty fertile. It is fairly acidic and its optimal acidity is 5,8 pH.
Peaty soil retains a lot of water, which is the main problem with this type of soil. If you build good drainage and work on soil structure, you will have a good, fertile soil perfect for optimal plant growth. This type of soil is widely used as an amendment to other types of soil to improve water retention.
How to Improve Peat Soil
Use lime or mushroom compost if you’d like to reduce the acidity.
Plants for Peaty Soil
Since this type of soil is fairly acidic, you can choose plants that thrive in an acidic environment – Rhododendron, Root Crops, Salad Greens, Brassicas, Lantern Trees, Witch Hazel, Camellia, etc.
Chalk or lime-rich soils have high amounts of calcium carbonate, sometimes with visible chalky lumps of stones. This type of soil is highly alkaline (pH of 7.1-8.0), but quite poor in nutrients.
Due to its porosity, chalky soil drains quickly. Chalky soils are often shallow, stony, lightweight and easy to work with.
How to Improve Chalky Soil
The problem with its nutrient deficiency can be resolved by using appropriate fertilizers. Use plenty of organic matter to help improve water retention.
Plants for Chalky Soil
Choose plants that prefer alkaline soil – Lilac, Dianthus Weigela, Madonna lilies, Heuchera, Scabiosa, Mock Oranges. Vegetables such as spinach, beets, sweet corn, and cabbage prefer chalky soil.