It's Wednesday which means its time for the word of the week. This week we are looking at my understanding of the word vermiculite.


A naturally found mineral that is used in many industries including building and gardening. This material is close to asbestos in its insulation properties. Don't worry it is not dangerous like asbestos. When this mineral gets very hot it is known to expand and "stretch".

I would sometimes get confused with this and perlite. They are both very similar in both their appearance and usage but there are differences. I wrote an article last week about perlite. Adding vermiculite to potting mixes or compost improves water and nutrient retention but it's not so good at improving aeration. Many gardeners add this mineral to all their gardening tasks

I use vermiculite in potting mixes particularly my seed sowing compost to improve germination rates. I will also add it pots or baskets to hold onto more moisture for the plant. Come to the end of the season the compost containing the mineral all gets placed into the compost bin as it will not do any harm and is a natural product.

Mixing vermiculite with compost I use a mix of 1 part vermiculite to 4 parts compost.


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