Desert Cacti and other Succulents:
Desert cacti and other succulents do not like to have ‘wet feet’ and need to be grown in a very well drained soil mix, there are a number of pre mixed cactus soils on the market available from garden centres but I have found most of thee to be of poor quality and full of cheap fillers and overpriced for very small bags, and when you have as many as I have 500+ a small bag of cactus compost is not going to go far haha!
I find it far more economical and better quality to make up my own cactus and succulent soil as I know exactly what is in it, different growers will have their own preferences with what they want to use but I have had very good success with making up my own soil with 3 equal parts that consists of 1, a soil based compost, (I use John Innes no2) Horticultural sand, and grit, you can use perlite instead of grit. The added sand and grit/perlite adds extra drainage. I would avoid using composts with added peat as much as possible with the desert types of cacti, as I have found peat based composts also encourage soil pests such as Fungus gnats/Sciarid flies, and peat has a tendency to dry like cardboard and is difficult to get to re wet again once the plants have dried out. I however use it when re potting Epiphytic cacti.
Here is a video I made for my You tube channel on how to make your own cactus compost:
Here is a video below that I have made on How to repot a cactus :
Unlike the Desert cacti, the Epiphytic cacti prefer to be kept moist all through the year, and although they can survive periods without water they dislike being kept dry for too long, and therefore do not like as sandy a soil mix as the Desert types, however they still need good drainage and I prefer to make my own growing mediums for these plants and I will use a good quality houseplant compost but with added 25% perlite. You can also use a good quality orchid compost with the Epiphytic cacti providing it is of a good quality.
If you are not sure if you have an epiphytic cactus or a desert cactus watch this video below that I have made for my You Tube channel explaining the differences :
Here is a video below I have made for my You Tube channel on How to repot a Epiphytic hanging cactus :