Sand is often being mentioned as an important ingredient in succulent potting mixes and it is indeed used in creating all kinds of growing media. But can you grow succulents in just sand?
Sand, as a single ingredient, is not suitable to grow succulents. Sand is incredibly heavy and holds onto too much water once wet. Because of this sand is very likely to suffocate the roots and rot the plant. The hardiest succulents should survive being grown in sand but they are unlikely to thrive and look their best.
So why is sand touted as this vital part of the potting mix? To be honest, in my opinion, sand is a bit of a cheap ingredient and I steer clear of potting mixes that use too much of it . Our nursery plants never looked great and were less likely to survive extreme conditions (heatwaves/ heavy rain) when we trialled mixes heavy on the sand.
There are succulents that in their natural environment grow in sandy soils. Some coastal succulents also often grow in sand, but it can be hard to completely imitate the natural environment of a plant- the climate, rainfall and the exact type of medium that is endemic to their natural location. A much better approach is to get a good all-rounder succulent potting mix.
Our current potting mix (made by a company producing potting mix for nurseries based on type of plants) has a little bit of sand but it is hardly visible. Much more prominent ingredients are pine bark fines, lots of gritty minerals & pumice/ perlite. The size of these helps with drainage when substantial rains hit, the roots can spread easily and the minerals release nutrients which succulents thrive on. Our potting mix is also very light and we use it to grow some 300 different species
It is especially important to have good potting mix when growing succulents that are a little bit precious and rare such as many hybrid Echeveria, variegated succulents, cacti. If you’re collecting succulents and growing them in pots, the best results will be achieved with a professional potting mix.
The hardy, garden varieties such as many Graptopetalums, Crassulas or Sedums will grow fairly well in substandard potting mix when in pots and will also deal with sandy soils in the garden.
Many succulents are much more hardy and forgiving when in the ground and usually grow better than their counterparts in pots. But even they will thrive more if the soil is a little more gritty and a bit of succulent potting mix is worked through the existing garden soil.
In conclusion, succulents will not like being grown in sand only, especially if in pots. Some will tolerate sand if planted in the ground, but they will probably not flourish.