I've just acquired a couple of Pilocereus from an old collection that is being disposed of to grow in my greenhouse. They've been ID'd as P. leucocephalus (= palmeri) and P. pachycladus (= azureus). Do any of you folks have the kind of climate that allows these to be grown outside? The Brits are telling me a winter minimum temp of +5C (41F) - but 30 years ago the cautious Brits were telling me you couldn't grow any cacti outside Not that these are heading outdoors, I have a greenhouse I keep frost-free with a minimum of +2C (36F) I've read elsewhere they will take 0C (32C) if dry - any realtime experience?
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I'm in the Phoenix area of AZ and grow many species of Pilosocereus in-ground.
Temps in the Winter here regularly drop below 32F (though less frequently in recent years).
Mine show no damage down to 27F; however, keep in mind, our daytime temps rapidly increase at sunup so rarely do temps stay below freezing for more than a few hours at a time.
I don't tend to water in the Winter when it regularly gets below 40F at night, though our winter rain pattern usually has rain preceding the cold fronts that cause temps to drop.
Pilosocereus here are challenged more by our intense Summer sun than any cold we can throw at them.
I have the very same two species outdoors in ground. They take down to low 30's for me and the "warmup" after that here is a the usual 50f or so from the cold morning. Great looking if slow to get to a large size. My largest is over 6' and in that spot about a dozen years now.
I have a slightly different experience compared to Tristan. I lost a large-ish P. pachycladus going on 7 ft multi armed. After a wet cold spell a winter about 8 or so years ago. protected the growth tips, but I guess it was just wet/cold enough (I doubt it touched freezing, so mostly blame the wet) for it to catch some rot, that I was unable to stop. Saved one arm for about a couple of years that then got done in by a hot summer - it just never was right after than incident.
I am trying again and without too much hesitation have been putting random finds in Big Box stores in the ground - if they are too small they are toast in the summer, but I have several that are starting to be reasonably sized. My P. pachycladus when happy was a tank in the summer, but some of the other species look like they could use some shade from the absolute crazy summer sun.
Paul S wrote: ↑Mon Jul 17, 2023 12:43 am
I've just acquired a couple of Pilocereus from an old collection that is being disposed of to grow in my greenhouse. They've been ID'd as P. leucocephalus (= palmeri) and P. pachycladus (= azureus). Do any of you folks have the kind of climate that allows these to be grown outside? The Brits are telling me a winter minimum temp of +5C (41F) - but 30 years ago the cautious Brits were telling me you couldn't grow any cacti outside Not that these are heading outdoors, I have a greenhouse I keep frost-free with a minimum of +2C (36F) I've read elsewhere they will take 0C (32C) if dry - any realtime experience?
IMG_20230716_132804.jpg
IMG_20230716_132810.jpg
I agree that too many growers of cacti would rather claim that higher temperatures are a requirement, but the truth is harder to come by. In my experience, this genus will remain unharmed if the temperature is above 25˚ F.
With the cost of energy these days, I'd rather save my money to buy more plants!
As for me these ones are as tender as Melocacti that's why overwintering with most part of collection in cool garage didn't succseed and I have to overwinter them in room.
I have seen Pilosocerei freely growing and flowering in Algarve, Portugal.
A small front yard I saw a few years ago had planted blue Pilocereus cactus with Golden 'torch' Straussi and some kind of white wooly cactus and it made a great look. Very eye candy.
Not that these are heading outdoors, I have a greenhouse I keep frost-free with a minimum of +2C (36F) I've read elsewhere they will take 0C (32C) if dry - any realtime experience?
