Aloe speciosa (literally, the beautiful Aloe) was the species that sparked my personal love for tree aloes. I'm not entirely sure why they're my favourite group but it's probably the drama of their scale and often spectacular flowers. They are a powerfully exotic presence in any garden and it can be a surprise to learn that they can be amongst the easiest to grow of all this varied and sometimes difficult group of plants. At least that is my experience, and I live at the edge of outdoor climatic viability.
Speciosa hails from rocky slopes on the West and Eastern Cape regions of South Africa, where it occurs at moderate altitude of up to 800m, according to Aloes The Definitive Guide (Kew). The climate in this region is variable but generally drier and a little warmer than here on the coast of Otago in NZ, though we share a Mediterranean pattern.
I've grown this species outside and unprotected for about eight years now, with this specimen > being the largest of a trio in my front rockery at around 1.4m tall, at which height it has flowered for the first time. It receives winter rain, hail, snow and the occasional frost, although the ground never freezes here.
BELOW The leaves are tightly spaced along the stem and bear this diagnostic internode pin striping.
They dry down to form a straggly skirting that possibly protects the trunk from weather extremes, although it also provides the snails and slugs that like to munch the surface of the leaves with a convenient diurnal hideout.
< This species is also known at the Tilt (or Tilt-head) Aloe because its heavy blue rosette grows at a rather emphatic 45º angle to the stem and seems to insist on pointing due north, no matter where it is planted. That is certainly true in our location; I wonder if the orientation is reversed in the northern hemisphere.
The basic colour of the gracefully-curving, soft-spines leaves is bright medium green but this is converted to a particularly attractive turquoise blue by a waxy glaucous coating that seems to protect speciosa from much of the fungal spotting that can afflict aloes in humid climates. Both this and its aforementioned tilt also protects it from being damaged by the worst of the hail and snow that comes zinging out of the south in southern latitudes.
If molluscs are a problem in your area, you might want to either thin the skirt enough to allow birds to predate anything lurking inside it, or remove the dead leaves altogether.
Aloe speciosa seems a tough and pretty forgiving plant despite its soft leaves and luxurious demeanour. We had a bad freeze (down to around -5º) here in 07 which resulted in superficial leaf damage but recovery was rapid and complete. I planted my smallest in a too-dark hole in unsuitable claggy soil which resulted in root loss and toppling during a particularly wet winter; that specimen barely skipped a beat, developed strong new feeder roots and I've since replanted it elsewhere.