Cacti bring joy and can enrich any area, they can thrive indoors or in an outdoor environment. They are beautifully sculptural plants and are versatile, chic and make the perfect ‘evergreen plant’ – even for the most forgetful of gardeners!
Although we classify most cacti as desert plants, even these “desert” plant varieties hail from differing habitats across the globe thus each can require slightly different environmental conditions. It is because of these differing needs that we highly recommend you do some research into the exact genus of your prickly buddy to get an idea of his specific needs. That being said – Cactus Vision has some general tips you can apply to most cacti species to help you remain a “cacti lover” opposed to a “cacti killer”.
Before you select a prickly friend for your home, you first need to consider the best position for him/her to sit. Too much or too little sun/water can be fatal for your cacti; so just like Goldilocks, your cactus needs a home that is “just right”.
The first consideration for your indoor cactus is of course LIGHT.
Place your cacti close to your sunniest window, NORTH EAST facing windows are usually best. Although dependent on the species, we recommend placing your cacti in a location where he receives at least 3 hours of direct sunlight through your window (on a sunny day) and an additional 4 hours of indirect sunlight (shaded sunlight), daily.
Although it is difficult to have “too much light” indoors, you should always rotate your buddie from time to time to discourage sun bleach marks forming on the light facing side. Rotating your cacti indoors also encourages even growth so your cacti don’t stretch out (in search for light/energy).
The watering of your cacti indoors (and outdoors) completely depends on how much sunlight you are feeding your plant. If your cactus is given too much water yet doesn’t have enough light for growth, the plant will struggle to absorb its drink, which can cause rot (thus death).
The best rule of thumb is watering your indoor cacti once a fortnight through Spring – Autumn and monthly through Winter. It is that simple.
If your cacti are getting a splendid amount of full sun through the warmer months, you could even water as frequently as once a week to help promote growth.
Cacti appreciate ventilation to minimise the risk of bacterial infections. Although this isn’t common, CV advises that you open a window or door occasionally to encourage good air flow. Air conditioners can be used in a large room with cacti however CV recommends that you try to avoid drastic temperature changes so that you don’t confuse the plants’ seasonal cycle. We don’t advise positioning your cacti within a 3 metre radius of either a heater or air conditioning unit.
Outdoor Cactus love water in times of growth (Spring-Autumn), simply allow the soil to become dry between watering. You could water as frequently as twice a week through these months although once a week is usually acceptable. Checking the soil dryness with a water meter or with your finger is the best means of confirming if it is time to water. When it comes to Winter, Cacti like to sleep through these colder months. Keep watering to an absolute minimum; once a month, until it begins to warm up again.
For outdoor locations, we suggest positioning your cacti where they’ll either receive morning OR afternoon direct sunlight, opposed to full day direct sunlight. This will ensure they don’t dehydrate over summer (causing sun burn), this way you will not need to water them as often.
Cacti (like humans) can get sunburnt. If you know a heatwave is coming – slip slop & slap on some shade for your cacti. During this time, avoid transplanting, repotting or changing your cacti’s usual position.
If your cactus is suddenly moved into a high sunlit position, your plant can become sunburnt – even without a heatwave. Sun damage can happen within hours and can be irreversible.
When it comes to Cacti and frost, most plants can tolerate the cold, but they generally don’t like it. Once temperatures get below zero you should take certain precautions to ensure your cactus is either tolerant or protected. Cactus can be up to 94% water, which means sustained temperatures below can literally freeze them. If sub zero temperatures last for more than a few hours your cacti will freeze, and when they thaw out turn into a not-so-delicious slushie. Protect your plants by bringing them inside, build a greenhouse or simply throw a hessian potato sack over them to keep your cacti warm.
SOIL, FERTILIZER & POTTING
When selecting a pot, it is imperative that you choose something with a drainage hole. Without drainage, soil can develop nutrient toxicity – disrupting the PH balance and poisoning your plant over time.
Cactus Vision likes to plant cacti in pots that allow the root mass to double in size. Changing the soil once every 2 years (at the beginning of Spring) is recommended and CV likes to upsize pots at such time to encourage growth. If you don’t want your cactus to grow bigger, keep it in a similar sized pot and simply change the soil every 2 years instead. Checking the drainage hole for escaping roots is a great way to identify whether your plant has become rootbound. If you see roots creeping out, it is time to upscale your pot.
When it comes to soil, you need to aim for something fast draining, but also something that retains nutrients to feed your plant. Try mixing perlite, volcanic rock, sand and coconut coir. This mix will make your cacti most at home.
Cactus appreciate an annual fertilizer. In spring each year, spread some slow release cactus fertiliser over your soil, give it a mix with a little organic blood and bone – and you are set.
Words by Erin & Carl from Cactus Vision
Images by Editor Arrnott Olssen