care & grow guide: cactus

Do you remember the first plant you ever bought? Mine was a cactus - just a little one, covered in fine spines and white tufty bits of fluff (Cephalocereus senilis). I had absolutely no idea what to do with it, and often forgot to water it for at least a month at a time (oops)

Cacti make great additions to the home, are low maintenance, and easy to care for - providing they receive the right care. They are native to the desert, and have adapted to survive in harsh conditions in which they receive very little water for long periods of time. 

WATERING

Cacti do not like being watered too often! The required frequency of watering will depend on the season - in the summer, I'll water my cacti around once a week. As autumn sets in and the temperatures begin to fall, watering is reduced to once a fortnight, maybe even three weeks. In the winter, most cacti will begin to go dormant, so I reduce watering to around once a month. Always ensure that the soil is thoroughly soaked, and all excess water has been expelled from the drainage holes at the bottom of the pot. The soil should also be completely dry throughout before watering again. Many cacti will actually begin to shrivel slightly when they are thirsty, alerting you that they are running low on their reserve and require more water. 

FERTILISER

When spring begins, cacti come out of their dormant phase and begin growing again. This is the best time to use a fertiliser and encourage healthy growth. I use a concentrated plant food that is specifically made for cacti. Make sure to dilute the formula correctly, as too much fertiliser can have negative effects on growth and roots.  

POTTING

It's also really important to make sure that your cactus is potted in a suitable environment, otherwise the careful watering will all be for nothing. These desert plants need a really well-draining soil, otherwise the soil will stay damp for too long - the cactus won't be able to take in any more water, and the roots will begin to rot away. For my cacti, I usually purchase a specific cactus & succulent potting mix, and add a handful of my own ingredients; such as perlite, orchid bark and coarse sand. Another way to help with drainage is to use unglazed terracotta pots - terracotta is very porous and allows water to move freely. If the pot contains damp soil, you'll see the colour change! 

LIGHT

Cacti enjoy bright but indirect sunlight. An ideal spot for them would be a bright south-facing windowsill, underneath a timed growlight, or they can be outside under certain conditions. I only place my cacti outside during summer, and I ensure to place them in a spot that receives mainly bright morning sunlight. Midday summer sun exposure can leave them scorched and sunburned. However, not receiving enough bright light can make them stretch out as they try to get closer to a light source, making them irregular in shape and size - and unfortunately, this is irreversible.

An etiolated Opuntia Microdasys

PROPAGATION

Many types of cacti produce offsets when mature. Depending on the type, they can form at the base, along the stem, or on cactus pads. When the offsets are approximately one third the size of the parent plant, they can be carefully removed. Leave the wound to callous over for a few days, then plant in well-draining soil. Within a few weeks, the offset should begin growing its own roots. 

Many cacti also produce flowers, which can be pollinated using a paintbrush or toothpick. Successful pollination means that after a few weeks, the flowers will turn into pods, which could hold hundreds of tiny seeds!

So to recap the most important factors of a happy, healthy cactus:

• Water approximately every 1-2 weeks (depending on season)
• Fertilise once a fortnight during growing season
• Potted in fast draining soil
• Pot requires drainage holes at the bottom for excess water
• Bright, indirect light for healthy growth

Happy growing!