Reuse potting soil: beware of the pitfalls!

Why does it make sense to reuse potting soil?

growing soil or seed soil is also after it has already been used still suitableto grow more plants. Both their texture and their nutritional composition have not changed much. It is still loose and poor in nutrients. The plants to be grown, such as seedlings and cuttings, hardly need any nutrients in the first few weeks and therefore do well in the potting soil that has already been used.

Where are the pitfalls when reusing potting soil?

Potting soil that has already been used is no longer sterile. Over time, fungal pathogens, bacteria, pests, foreign seeds, etc. found in it. If the potting soil is used again, the young plants could be attacked by fungi, for example, and soon die.

When buying new potting soil, it is usually ensured that it is sterile.

How can you make a germ-contaminated potting soil germ-free?

You can use a germ-loaded potting soil sterilize. For this purpose, the slightly moistened growing soil is filled into a flat container such as a casserole dish. Place this container in the oven or microwave. The potting soil should be sterilized in the oven for about 30 minutes at 200 °C. In the microwave, 10 minutes is enough on the highest level. Heating the potting soil kills germs, fungi, pests and the like.

Should the potting soil be fertilized before reusing it?

If the potting soil has been used very often, it is not mandatory, but cheap if they bit fertilized becomes. However, a biological fertilizer such as compost or coffee grounds should be used for this. Be sparing, however, as too many nutrients will do more harm than good to the grow.