What soil is best for growing succulents?
Succulents need free draining soil. We see that on all the plant labels, but what specifically does that mean?
For growing in pots there are commercial mixes available of course, but it is interesting to know what they contain or how to create your own blend.
A popular ratio is:
3 x parts Potting soil
2 x parts sand or grit
1 x part perlite or pumice
- Potting mix on its own holds too much moisture for succulents, taking too long to dry out. Roots are likely to rot sitting in damp soil, especially the slower growers, such as cacti or Agave.
You need to break it up for better drainage using the sand and perlite.
- Succulents are able to grow in garden beds of sand but watch it doesn't compact too much, which the finer sands might tend to do. Likewise, succulents can grow in a rock garden of 'just rocks', but because of the absence of any water holding material, they are going to need more regular watering. This defeats the purpose if your intention was to grow a 'water-wise' garden. A rock garden or sandy soil will benefit from added soil for happier plants and for lower water consumption. Small pebbles and or sand added to the potting mix aerates the soil allowing for freer drainage.
- The purpose of the perlite or pumice is to create space for free drainage. An alternative is activated charcoal which acts like a sponge to absorb moisture, and may deter insect infestation in the soil. Styrofoam pearls can also be added, but choose a plant-safe form, and keep the environmental impact in mind. It is particularly beneficial to double its ratio for cacti and the succulents with fleshier roots such as Haworthia and Gasteria.
- Finally, when creating a potting mix for your succulents you might like to add a small amount of slow release fertiliser.
To summarise, the best soil mix for your succulents must be free draining and able to dry out completely between each watering.