You may think that a heatwave is ideal for cacti but the amount of heat that these spiny plants can tolerate depends on what type they are; some thrive in extreme heat, some will need more protection.
Deserts are the natural habitat for cacti so they are used to temperatures of around 25°C in the day, some will even put up with 32°C but anything over that and it is very easy to heat stress your plant.
But cacti do appreciate being outside in the summer months, so to keep them healthy in the heat, here are some tips:
Move them out of direct sun in the hottest part of the day, usually between 3 -6pm. If this isn’t possible then cover them with a light sheet, remember to take if off once the temperature drops.
Plant your cacti in containers that will insulate your plant against sudden fluctuations in temperature. Ceramic, terracotta or wood are best for this. Avoid metal and plastic.
Remember that plants in containers will heat up more quickly than those planted in the ground.
They still need watering! It’s important to keep your cacti hydrated, but not overwatered. Water in early morning or last thing at night for them to get the full benefit.
Danger signs
Patches of pale white on the stems and spines mean that your poor cactus has been exposed to too much heat. The damage is irreversible, if possible carefully cut away the affected area.
And finally – if you have forest cacti, such as Rhipsalis, they also love being outside in summer, but as their natural habitat is the tropical rain forest they should always be in semi-shade.
Think I might join them!
Su Whale
