Delospermas are hardy to Zone 7, some to zone 6. RJ

The habitat they come from would also influence their requirements. Winter rainfall Cape species could be expected to be more tolerant of winter rainfall, plants from the Drakensburg Mountains could be expected to prefer it drier in winter, and wetter in summer. Unless species are coming from particular microclimates which due to location and altitude significantly increase the rainfall, much of the Western Cape is more similar to Los Angeles in rainfall than northern California, except it falls over a longer season, and is generally more predictable, as is also true of the Karoo and the Namaqualand succulent flora, which get more reliable yearly rains than most other deserts around the world, limited though it may be.

Joe, I have kniphofias, delospermas, ruschias, and a few odds and ends in my well-drained cacti beds. All do quite well and I expect if tried, we'd find more that do well.
I know from your postings, I don't have to say "experiment" and find some more.

Hi,

I guess I'll report back to you all in time. The seedlings I'm growing were chosen first and formost for ability to handle an occassional dip to 20 F or even a bit below.

I'll just let them go in clay pots with coarse sandy soil and see what happens. If I get ambitious I'll split each species into 2 pots and turn 1 pot on its side for that season in which the plant is expecting dry conditions. I've got summer growing seedlings now, and hope to start some winter growers when temperatures cool down.

I'm confident that some will be tolerant, but I guess there is just a limited data set for now.

Cordially,

20F should be doable for a lot of things. I believe Gauteng province goes below freezing at times so plants there can handle it. Stuff from the Drakensberg/Free State also experiences frost. The magic number seems to be 15-20F. Below that, we lose a lot of things here that people farther south in zone 8 don't lose. It also depends on how long it stays there and whether it is wet which promotes rot. RJ

Hi Joe,
here in South Island NZ, I've been growing a number of aloes for some years, but am only beginning to come to terms with the different rainfall requirements, which seem to be the limiting factor in marginal climates such as our own, rather than the cold itself. Most aloes will survive frost, but basal rot is almost always lethal, much like agaves.
Offhand, a few wet tolerant species to try are plicatilis (frost to -4 deg C), brevifolia and brev x nobilis (-4 to 5), aristata of course, X spinosissima(-4), and striatula, which has tolerated an incredible -9 without damage, and reputedly recovers from -12.
Like you, I'm also trialling some species such as striata, vryheidensis, krapohliana, suprafoliata, grandidentata, broomii, humilis, and others, but they haven't been in the ground long enough at our new house to indicate much about their hardiness.
Let me know if you'd like a list I have of hardy aloes, with temps in Fahrenheit and some notes about moisture requirements.
hope this helps,
Douglas