Care Diary: Aloe suprafoliata, or the Book Aloe

Written ByJen Greene

Posted: November 10, 2021

The Book Aloe is an uncommon species that is extremely striking as a juvenile, but seldom recognized in its adult form. I discovered the species during the COVID lockdowns in 2020, and picked up a handful to grow up and eventually use as landscape aloes (and also to produce seed!). 

I was worried that they would turn out to be finicky or challenging to grow, but as it turns out, they thrive on mild neglect. This is particularly the case if you’re in a warm and sunny climate (as I am), but I strongly suspect they’d also do quite well being treated like a cactus in more northern latitudes. 

book aloe

These aloes get their name because as juveniles, they grow in a very distinctive, stacked pattern, resembling an open book!  

This only lasts as long as they are juveniles, however, and once they’ve reached an age where they are ready to start blooming, they grow in a spiral pattern like a typical aloe. 

Fortunately, the juvenile stage is long lasting, especially if you grow your aloes hard (with the bare minimum of water and waiting longer between repotting).  A hard-grown Aloe suprafoliata can stay in the juvenile form for years! 

I’ve heard of some book aloes staying in the juvenile form for over 10 years, although it’s more common than they outgrow it sometime between 3 and 6 years of age. 

Origins 

Aloe suprafoliata is a species that comes from South Africa, around the Swaziland area, from mountainous regions. 

While from South Africa, they are typically found in higher elevations, in cooler, high-lying areas on rocky slopes. They usually experience heavy mists due to their elevation, but sparse actual rainfall. 

General Care

These are, fortunately, very easy aloes to care for. 

I have grown them in full sun exposure to nearly full shade and everything inbetween, and they haven’t minded any of it. If you like your Aloe suprafoliata to be on the greener side, then you’ll want to grow it in more shade. For the beautiful reddish-purple blushing against a blue base, you’ll want close to full sun combined with a sparse watering schedule. 

aloe suprafoliata

My first Aloe suprafoliata about a month after planting; this was spring of 2020, so we had frequent cloudy weather and cooler temperatures. You can see the reddish blushing on the edges, but overall a green-blue coloration. 

book aloe high stress

Book aloe pup from July of this year, freshly watered but still showing signs of stress: very red tips, leaves curving in, and crisping leaf tips. The tight, compact growth is also a good sign of not being “spoiled”, and that the plant is growing slowly, extending the period it spends as a juvenile.  

These aloes, more so than other species, require closer attention and more familiarity with “reading” your plant than other species tend to. If you want to cultivate a specific appearance, you’ll have to watch your plant and learn your region. If you’re in the northern parts of the US, for example, you may never get enough direct sunlight and heat to get a good curve and bright red color unless you use some supplemental lighting, especially in winter months. 

When potting these, you’ll need well draining soil and a smaller pot than you might expect if you want to keep it in the juvenile form for a while. Most available succulent and cactus soils are still too rich in organic matter to work as a fast-draining soil, so you’ll want to add at least 1 part pumice or perlite for every 3 parts soil. If growing in full sun, you can keep the soil more on the organic side, as the plant will appreciate having more time to absorb water. In shadier exposures or climates with more cloud cover, you’ll probably want to increase your ratio of soil to inorganic medium to about 50:50 to ensure rapid enough drainage. 

Water Needs

Even in my hot climate, in a greenhouse, and under potted, these need far less water than you might expect.

In summer, like other aloes, they’re on the semi-dormant side; they’ll continue to grow, but not as fast as they do in cooler months. The plant pictured right is showing key signs of typical summer stress: curled leaves, significant red blushing along the leaf margins and tips, as well as crisped leaf edges.

These aloes thrive in low water conditions, so even at the low-water stress level – that’s fine! Let your aloes approach this level of thirsty. 

mature book aloe

Notes on Blooming and Long Term Care

As with many aloe species, these are a winter blooming variety. My sole mature plant has bloomed in late fall, with the first bloom stalk appearing in October last year and this year. The bloom stalk takes about a month to fully develop and open flowers, so the first blooms aren’t open until mid to late November. 

When night time temperatures start dropping into the 60s and 50s, I start increasing water frequency and thoroughness; while watering the top layer of soil in a rootbound plant works well for the ‘dormant’ summer season, they need more water in cooler weather to bloom properly. September is usually when things start to cool off at night, and that’s also when I start fertilizing regularly. 

Fertilizing is simply using a cactus fertilizer roughly once every 2 weeks, or a balanced regular fertilizer at 1/2 strength at the same frequency. The fertilizer encourages blooming, as well as enthusiastic winter growth – so if you don’t want your plant to reach maturity too fast, skip the fertilizer! 

I plan on placing my mature aloes in-ground in the coming months, so long term, they’ll have that benefit to encourage robust growth. For those trying to maintain the coveted juvenile form as long as possible, you’ll want to give it just enough care to thrive. 

That means keeping it under-potted in pots that are a shade too small, watering it less than you might prefer, and keeping fertilizer to a minimum. If your aloe is under-potted and also planted in a medium with minimal organic matter, you’ll probably need to fertilize at least a handful of times a year or risk killing the plant from lack of nutrients. 

These are enormously rewarding plants, and even in their adult rosette form, they are extremely attractive! To follow along with my cultivation,  you can follow me on Instagram @trexplants. I also offer these for sale occasionally through my Etsy shop

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