With good drainage, many succulents grow well outside
As a lifelong lover of succulents, it’s exciting for me to see that they are suddenly back in vogue. Driven in large part by social media, sales of these wonderfully low-maintenance houseplants have seen a sharp increase in recent years. But despite their incredibly exotic appearance, many succulents will grow perfectly well outdoors. If you have run out of windowsills for your growing army of desert plants, here are some of my favourite aloes that will let you increase your collection outside.
We tend to think of aloes as larger, statement plants when grown indoors, but if you have a sunny spot outside, the low-growing, bunching rosettes of Aloe aristata make a wonderfully effective ground cover. They help green up the bare patches of gravel between bigger specimens in dry or Mediterranean-style borders, where they will also suppress weed growth, and even reward you with spikes of bright orange tubular flowers held on elegant stalks each summer.
Like many cold-hardy aloes, they will take really low winter temperatures as long as they aren’t sitting in moisture over winter, so ensure they have excellent drainage. One way to do this is to incorporate loads of gravel into the bed beforehand – we are talking near 50%. Another way is planting in the rain shadow of a house, where plants will also benefit from slightly higher temperatures thanks to protection of the adjacent walls. In these locations the slender, rambling canes of Aloe striatula are an excellent candidate. They can eventually grow up to 8ft high, crowned in summer with sulphur yellow and red-hot poker-type flowers. They are easy to grow from cuttings, which means you can give them to all your mates and, despite the fact that prolonged cold snaps can decimate the top growth, they invariably bounce back from below ground level come the spring.
The most exotic-looking, though, has to be Aloe polyphylla. With leaves arranged in mesmerising, geometric swirls that spiral out in a Fibonacci pattern, you might assume I am talking about something you would have to look at through a hand lens to see, but these are pretty massive as aloes go, eventually growing to rosettes over 50cm across. Coming from steep mountain slopes over 2,000m high in its native southern Africa, it can take temperatures down to at least -15C if given perfect drainage. At Kew Gardens there are some wonderful outdoor specimens in the grounds, protected from excess winter wet with plastic covers. However, I find growing them in porous terracotta pots does exactly the same job of keeping out the winter sogginess, but in a more aesthetic (and easier) way. So whether it’s in garden beds, patio pots or against sunny walls, there is an outdoor aloe for pretty much every situation, not just indoors!