What type of soil is best for my plants?
You may know the feeling. Spring has begun and you are at the garden centre, but you do not know what type of soil to get. What kind of soil is good and what kind is not good? Maybe you are afraid that you buy the wrong type of soil. This blog provides you an overview and I will focus on soil for the greenhouse.
Make a plan
Before you make any decisions of what to buy, you should begin with what ideas and plans you want to fulfil in terms of cultivating this season. Consider the following questions before you start:
- Will I be pre-germinating myself?
- Am I cultivating in plant beds?
- Do I prefer capillary boxes?
- Do I like cultivating in pots?
If you answered “yes” to all four questions, you should look for four types of soil. You do not have to look for a certain brand instead you can look for the purpose of the soil.
The four main types
- Potting soil is permeable and without too much fertiliser. The soil is great for germinating seeds and young plants. Often you do not need a lot of potting soil. 20 or 30 litres are an unnecessary big amount of potting soil, so look for bags with 8 litres – it will be enough for most people.
- Soil improver is for you who cultivate in plant beds in the greenhouse. The ‘old’ soil may need more nutrition in spring. To do this you can use soil improver. Soil improver adds more nutrition and improves the structure of the old soil, so it gets airier. Soil improver is often sold in bags of 40 to 50 litres.
- The growbag is for you who uses capillary boxes and want things to be easy. Tomatoes, cucumber or chillis are transplanted directly in the bag. Before you transplant, cut a hole in the bottom of the bag so the soil and water are in contact. The soil is great to provide the roots enough oxygen all summer. The growbags can be bought in 40 and 50 litres. I prefer the ones that are 50 litres because they can contain more water and the roots have more space.
- Soil with clay is for you who want to cultivate in containers. The soil is heavier than other types of soil since clay is added. However, this is not visible. The clay helps retaining the water in the soil. It is important to use soil that can do this to avoid the plant in the pot to dry out. Usually, fertiliser is already added so you do not have to remember to fertilise all summer. Often the soil comes in bags of 40 to 50 litres. It may surprise you how much soil a pot can contain, so my advice is to buy a large bag or two bags.
Well, that was really all…
You do not really need to know more than that about soil. It is only the four questions and the information about the four main types of soil.
Soil with sphagnum
Sphagnum is a type of moss. What makes sphagnum great for cultivation is its ability to retain large amounts of water, and at the same time provide oxygen to the roots. The quality of soil with sphagnum varies, but price and quality usually go hand in hand. The more expensive, the better it is.
Soil with compost
Sand is mixed in most soils with compost, and therefore, it feels heavier than sphagnum products. The benefits of a compost product are that they contain micronutrients and macronutrients and different kinds of organic matter. Sadly, this also means that compost products contain living organisms. During transportation and storing at a garden centre or home improvement store the product can continue its decomposition process. This affect the product and means that what you ordered may not be the same as when it was dispatched. It is an ongoing issue and many of the products you can buy are very different.
Storing growbags 1-2-3
- Place the growbags on top of each other vertically
- Avoid storing the bags for too long
- Place a tarpaulin on top of the bags to keep them dry
- Avoid the bags getting damp
- Store the growbags in the shade before you use them
Planting soil should not smell bad. But when it comes to growbags with organic fertiliser like chicken manure, it may smell when you open it – that is perfectly normal.
Christine Wiemann is a greenhouse grower and an agricultural technician and owner of the seed company Spirekassen. Christine is an author of several books about lifestyle, garden life and plant cultivation. Today she writes blogs and shares her knowledge and passion for greenhouses. Christine is a greenhouse expert and an ambassador for Juliana Drivhuse.Get to know Spirekassen
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