You can process your own or purchased compost into compost soil by mixing it with other ingredients. We provide matching tips and guides.
If you own a compost heap or can obtain cheap compost, you can produce compost soil flexibly and according to your needs. Below we give you instructions for compost-based potting soil for summer flowers, vegetables, cuttings and seeds as well as herbs and woody plants. You can also find out more about the benefits of having your own compost heap here and in this article you will learn all about the properties of compost.
Tip: If mixing it yourself is too much effort, you will find high-quality organic potting soil for a wide variety of plants in our shop.
You have your own compost and would like to mix potting soil with it? With a view to the needs of different plant groups, we have put together some mixtures for you that you can easily make yourself. You can sterilize your own compost before use to kill pathogens and weed seeds. This can be done either in the preheated oven (10 to 20 minutes at 200 °C) or in the microwave (10 minutes, 800 watts). However, only heat three to five liters of compost at a time so that the entire quantity is sterilized evenly. If sterility is not extremely important to you - for example for the cultivation of young plants - you can safely skip this step. Eventually, by doing this you will also kill any other useful life in the compost.
All figures below are given as percentages by volume, so you can mix with a very large measurer or just a green thumb and a sense of quantity.
Mixing compost for summer flowers
Summer flowers on beds and borders are usually annuals and are used to a consistently high supply of nutrients from their cultivation, which the substrate should offer them. You can spread this out before sowing or planting and/or add each individual plant to the planting hole.
- 60% finished compost
- 20% fresh compost
- 10% shredded ericaceous plant leaves
- 10% bentonite or vermiculite
- Some horn meal
Mixing Compost for Vegetables
Compost soil for vegetables should not contain too much nitrogen so as not to hinder fruit set through excessive vegetative growth. Since tomatoes (Solanum lycopersicum) and cucumbers (Cucumis sativus) in particular have a high water requirement, good water retention is also useful to make hot summer days better to survive.
- 70% ready compost ( alternatively: 50% ready compost, 20% fresh compost for crops with high nutrient requirements)
- 20% xylitol ( alternatively: 10% coconut fiber and 10% softwood shavings or crushed leaves of ericaceous plants)
- Some slow-release organic fertilizer (if the compost was made from nutrient-poor material, then a little more)
Mix compost for summer flowers in the bucket
Pot plant soil should store water for a long time and keep it readily available without too little oxygen being available at the roots. Nutrients should also be available long-term and evenly in order to minimize the maintenance effort.
- 50% finished compost
- 20% wood fibre, preferably from softwood
- 20% coconut flour (cocopeat)
- 10% bentonite or vermiculite
- Some organic long-term fertilizer (if the finished compost was mainly made from green waste, then a little more - if the finished compost was mainly made from organic waste, then a little less)
- Some horn meal
Mix compost soil for cuttings and for sowing
Compost soil for young plants must be low in nutrients and well permeable to air. Although more frequent watering is necessary, the resulting roots become strong and do not rot.
- 50% mature compost ( alternatively: coconut flour (cocopeat) and bark humus)
- 30 % perlite ( alternatively: rice husks)
- 20% xylitol ( alternatively: 10% coconut flour (cocopeat) and 10% softwood shavings or crushed leaves of ericaceous plants)
Mixing compost for herbs
Most herbs would grow satisfactorily in reasonably good, humus-rich garden soil. Optimally suited - especially for planting Mediterranean herbs - is a well-drained, slightly nutrient-poor soil.
- 30 % mature compost
- 40% sand
- 30% coconut fibers ( alternatively: mature compost and sand each 50%)
- Some rock flour
- Some slow-release organic fertilizer
Mixing compost for shrubs
Trees like the boxwood (Buxus) are occasionally cultivated in pots. There is also a very suitable and simple mixture with ready-made compost for them.
- 60% finished compost
- 40% broken bricks
- Some slow-release organic fertilizer
Tip: make your own compost
Would you like to make your own potting soil, but don't have your own compost? If you're still unsure, this article, which covers the benefits and workload of the compost heap, may help. Composting is an ancient principle that you too can carry out with a little background knowledge, practice and the right equipment. The principle is simple: the composting is carried out by small and tiny creatures - worms, snails, bacteria, fungi and insects. However, good composting is only possible if the living conditions are good enough. The right selection of the compost material, any auxiliary materials, the right composter and the location are crucial for this. And you will need a bit of patience, because it can take up to two years to rot until the compost matures. You can read everything you need to know about “proper composting” in this special article.