How to keep cacti happy


The meteoric rise in popularity of cacti and succulents shows no sign of abating. Making a break from their normal retail habitat of the houseplant section in garden centres, this Christmas I have seen big displays of them in the homewares sections of department stores, and even nestled between T-shirts in hipster clothes shops. So, if you find yourself with one of these little guys under your tree, here are three unexpected tips I picked up from a commercial grower on just how to take care of them.

When you step into the vast glasshouses of family-run growers Ubink just outside Amsterdam, your jaw drops at its sheer scale. They are now one of the world’s largest producers, supplying everywhere from botanic gardens in Thailand to roadside planting in Dubai. With three generations of growing experience stretching back to the 1920s, there are few people better to ask about how to grow these plants indoors in a northern climate.

The first thing that struck me was that on a sunny day in November vast stretches of their glasshouses were shaded. Given that cacti and succulents are notorious for their need for high light levels (and I have seen any number of sad, sun-starved specimens desperately stretching towards the light on restaurant tables), I needed to know more. “Yes, most cacti and succulents need as much light as you can give them,” says Gert Ubink. “But some succulents not only tolerate a degree of shade, but actively prefer it. When you go to their natural habitat, sometimes you don’t see anything until you are right over them, as they are hidden by long grass.” This makes genera like Haworthia and Gasteria great options for spaces further away from a window. While as a general rule most species require being within the first metre of the windowpane (light levels can halve for every metre you move away from it), Haworthia and Gasteria will tolerate being up to 3m in.

Then we talked about watering. Having bedded out cacti in the UK for the summer I find that, although they will (unsurprisingly) tolerate drought, their growth rate is dramatically boosted by a wet summer. Is this true? “Of course,” says Ubink. “We water once every five days in summer, far more than what you might think is needed to boost growth to a maximum. We use run-off from our roof. But in winter, this slows to just once every month. You have to keep them dry when light levels are low so they don’t rot. Once you get the watering and light right, they are very low maintenance.”

Finally, I spot a glasshouse of huge specimen cacti, some more than 3m tall. How on earth you do go about repotting these, I ask. “Simple. Take two pieces of leftover polystyrene.” Ubink sandwiches a sizeable plant between two slabs and uses them like spine-proof oven gloves to lift an incredibly spikey specimen effortlessly from pot to pot. Ingenious! I don’t know about you, but I for one will be saving any polystyrene pieces that come inside the boxes of Christmas presents this year.