Often known as the Twisted Cactus – and you’ll see instantly why – the Cereus Forbesii Spiralis is a welcome addition to any plant collection.
The origins of this quirky little cactus are not 100% clear, but it is generally thought to be a cross-pollination between the Cereus Peruvianus and the Cereus Forbesii.
This means the spiral cactus is likely native to Peru or Argentina. But it is for sure a South American species.
Initially, I was a little disappointed with mine – it looked pretty non-descript. That was until I learned that the trademark “twisting” of this beauty only begins once the plant reaches a certain height.
This generally occurs at around 4” to be precise. Thinking about taking one of these little gems home? Let’s find out all there is to know about their care……
Cereus Forbesii Spiralis Care
The Spiral Cactus or Cereus Forbesii Spiralis is really easy to take care of and a good option for beginners. As long as it is kept at above 10 degrees Celcius/50 degrees Fahrenheit it will do just fine. However, it will thrive in warmer temperatures – above 16 degrees Celcius, up to about 24 degrees) Make sure you don’t over-water it – do it only when the soil is dried out, and when young keep it in bright light but out of direct sunlight. For best results, use a Cactus soil mix.
Unless you live in a desert – whose soil these plants love – you’ll need to make sure you have the correct soil for the Spiral Cactus. Use a gritty soil base, one that drains quickly.
If you can’t get a hold of “cactus soil” don’t sweat – you can make your own. Simply add some fine pumice or sand 50-50 to standard potting mix. This should give the soil the gritty texture that the Cereus Forbesii loves, and helps with drainage.
The drainage abilities of the soil are super important for this cactus. It hates to sit in damp soil, and can die if overwatered. Taking the time up front to ensure the soil mix is correct will help keep your Spiralis healthy and happy!
When very young, let your Cereus Forbesii Spiralis bask in light, but not in direct sunlight. As it grows, increase the direct sun exposure only gradually. This will help prevent sunburn.
If indoors, make sure the more mature plant is in the light, preferably in a south-facing window.
If outside, you will need to take a little care that there is some shade for the peak summer sun. In general, the minimum amount of sunlight this little gem needs is about 5-6 hours, but preferably 8. Adult Spiral Cacti love the sun!
You won’t need to worry about getting the neighbours around to water the Spiral Cactus if you are away for a couple of weeks. It is a pretty drought tolerant plant, as you would expect. But it does need watered thoroughly when the soil is completely dried out.
However! Here is one of our strongest recommendations. Make sure you do not over water! Twisted Cacti are sensitive to dampness in the roots – known as root rot.
If you aren’t quite sure whether or not the soil is completely dry, hold off on the watering another few days to be safe. And during the winter, when the cactus is dormant, you can ease up on the watering a bit.
This spiral or twisted cactus loves mild to warm temperatures. Comfortable at around 16 degrees Celsius to 24 degrees (60 degrees Fahrenheit to 75 degrees Fahrenheit), you need to take care if temperatures drop much lower.
Generally, anything below 10 degrees Celsius is in the danger zone for this plant (that’s about 50 degrees Fahrenheit). If you are keeping this little guy outside, you might want to bring him in when the mercury falls to this level.
The Cereus Forbesii Spiralis is not a big fan of high humidity. I made the mistake of keeping one in the bathroom for a while – it didn’t work out so well. Normal levels of humidity in your home should be just fine, and it can tolerate also dry levels too.
You can- if you want – use a fertilizer specially made for cacti. Fertilise from the beginning of spring through to the autumn, but you don’t need to (and shouldn’t) do this in the winter months.
This is because the plant is lying formant. Fertilising should be done twice a month during growth season.
The spiral cactus is actually really easy to propagate from cuttings. Simply cut your piece and insert it into moist soil. The best time to do this is usually early spring. Once ready, replant them into cactus soil and watch them take root!
The young plant begins with a straight stem. In the wild, the Cereus Forbesii Spiralis grows multiple stems, much like the shape of a candelabra. The trademark and quirky twisting usually begins only at around 4 inches.
If you want your cactus to grow beyond the pot, you will need to repot it. Make sure you are prepared for what can happen if you repot every couple of years. Why? Well this cactus can grow up to 16.5 feet tall!
This leads us on nicely to a little note about potting! If your cactus is beginning to outgrow its pot, it’s time for a new home. Remove from the current pot and give it a little tidy up around the roots and soil.
Then move to the new pot. Add additional soil – with the appropriate grit mix for drainage, see above! We recommend not to water the newly re-potted cactus for around a week.
Common Problems with Cereus Forbesii
Whilst the Cereus Forbesii Spiralis is pretty easy to keep happy, you should be aware of the issues that can sometimes be faced if you don’t follow the above simple guidelines. Let’s take a look at common problems with the twisted cactus.
Mealybugs and scale are the main type of pests who love to hide out on your cactus. You may even find the odd spider mite too. In most instances, spraying the cactus briskly with water will be enough to dislodge these intruders.
We don’t really like recommending insecticides, but sometimes they are a must if you have a stubborn bunch of guests.
Root Rot we have mentioned – this fun plant hates to have wet feet. You may notice the roots becoming black and mushy. This may be an indicator that your soil is not the perfect mix for drainage.
You will need to cut off the damaged parts and repot the plant in the appropriate soil mix. You will also need to re-evaluate your watering schedule. Make sure you are following the guidelines above.
Be really careful with peak sun exposure. Unfortunately, the Cereus variety is sensitive to this. And sunburn is usually quite incurable and leaves unsightly brown patches on your lovely plant.
Make sure if you have it outside in peak season that you plant it near some midday shade.
Summary of tips for growing your Spiral Cactus problem-free!
If you must pick just 3 tips, here is our recommendation
– Soil, soil, soil. This is perhaps the most important. The drainage will make or break the plant
– Water. Follow the watering tips carefully and make sure not to over water
– Sun. Young plants are sensitive to sun, train them gradually. In the height of summer, protect even your mature plants from midday sun.
Frequently asked questions about the Cereus Forbesii Spiralis
Is the Cereus Forbesii Spiralis toxic?
The good news is no, and it’s not likely your kids or animals will want to touch it anyway, due to the spikes.
Can you grow Cereus Forbesii under artificial light?
Technically yes, you probably could begin to grow young plants under artificial light. But why deprive this species of what it needs. The spiral cactus needs up to a full day of sunlight to thrive
Why is my Cereus Forbesii Spiralis straight?!
Don’t panic. The young plant does not show spiralling until about 4 inches in.
Does the Cereus Forbesii Spiralis flower?
In the summer, larger plants can be expected to product beautiful pink and white blooms in abundance!
How tall does the Spiral Cactus grow?
This beautiful cactus can grow up to 16.5 feet tall! That’s about 5 metres!
Is the Cereus Forbesii Spiralis known by any other name?
Synonyms for this cactus include the Cereus Validus Spiralis, Cereus Peruvianus and the Spiralled Cereus.
How do I train my Cereus Forbesii Spiralis to twist?
The good news is you don’t! This cactus will naturally begin to spiral after about 4 inches of growth.
Follow these tips and your Cereus Forbesii Spiralis will give you loads of joy! Make it your mission to cultivate a perfect spiral form and let us see the results of your efforts!
Marcel runs the place around here. He has a deep passion for houseplants & gardening and is constantly on the lookout for yet another special plant to add to his arsenal of houseplants, succulents & cacti.
Marcel is also the founder of Iseli International Commerce, a sole proprietorship company that publishes a variety of websites and online magazines.