There are tens of thousands of different succulent species out there and the number keeps growing as new plants are being created by growers. Thanks to globalization succulents endemic to one part of the world are being grown world wide and sometimes the conditions can be very different to their home environment- dessert succulents grown in cold climates, for instance. Succulents can also have very different needs- some like lots of sun and some prefer a shady spot. The rain too worry a lot of succulent enthusiast. So is it safe to grow succulents outside?
The majority of succulents grow better outside and most will often struggle indoors (especially the sun-lovers), however there are circumstances when succulents will need to be sheltered and cannot grow outside.
Most succulents can't grow outside in countries with harsh winters as, apart from a few species like Sempervivum or some Sedum, succulents are not frost hardy. The water in the leaves freezes and the whole plant collapses into mush if exposed to frost for too long. Short exposure to frost is like to leave burn marks on leaves.
In cold climates succulents will need to be brought indoors or in a greenhouse in order to survive the freezing temperatures. Our nursery grows 95% of our succulents outdoors all year round but the temperature rarely drops below 1C (33.8F).
Some succulents also have hard time surviving in humid environments and so may need to be sheltered from the rain. Although, those succulents that need the sun to grow well will still need to stay outdoors on a covered, sunny verandah or in a greenhouse.
Water Sensitive Succulents
There are also succulents that can be a little too sensitive to the rain & water in general. The ones that immediately spring to mind are Echeveria Romeo, Echeveria Lauii and many Cotyledons. These plants will also need to be sheltered from the rain and only watered when the potting mix has completely dried out, though they also need lots of very bright light. Again, a covered verandah or a greenhouse may be needed to grow these.
To conclude most succulents will need to be grown outdoors to keep their shape and colours. Sun loving succulents will likely eventually die if grown indoors though there are shade-tolerant succulents such as Haworthia, Gasteria, Sansevieria that will survive inside. For those in cold climates, overwintering plants indoors is a must and sensitive plants will need to be kept under cover in tropical parts of the world or if it rains too much.