Lowest winter temperatures?

[fanaticactus]

Is anyone aware of a website that is specific enough to give the lowest recommended temperatures for potted cacti in winter? I have done a basic search for each genus but I can't always find a minimum recommended winter temperature range--plus, they don't always indicate if it is for a potted cactus or one planted outdoors. I have a greenhouse and, barring another horribly long bitter cold season, I try to maintain a nighttime temperature around 40F (5C). But during the day of early or late winter, because of the sun, the temperature inside can rise to as much as 85F (30C). I have a number of cacti that I know should winter over around 50-55F (10-13C)--Rhipsalis, Schlums, Epis--but I'd like to know about others I should bring indoors to an unheated room for winter survival. And are there any genera which do not either need or want a winter rest period? I have about twenty genera in my collection, and I did not want to have anyone try to address each one. That's why I'm curious to know if there is a resource for this info. Thanks in advance for any info you can supply.

[iann]

Check out Mesa Garden. They give basic hardiness ranges for all their cactus seeds. They're mostly on the optimistic side, possible in NM and not in England, but it will give you an idea. Most other sources are completely hopeless. I have a book (by some well-known cactus experts, bot random idiots) that claims Pediocactus are only safe down to 7C (45F), which is actually warmer than ideal for their main growing season. It also says Echinocereus triglochidiatus needs to be kept at 10C or above, maybe they got confused and meant 10F

[fanaticactus]

Check out Mesa Garden. They give basic hardiness ranges for all their cactus seeds. They're mostly on the optimistic side, possible in NM and not in England, but it will give you an idea. Most other sources are completely hopeless. I have a book (by some well-known cactus experts, bot random idiots) that claims Pediocactus are only safe down to 7C (45F), which is actually warmer than ideal for their main growing season. It also says Echinocereus triglochidiatus needs to be kept at 10C or above, maybe they got confused and meant 10F

I certainly hope he's wrong, Ian. If not, my brand new Pedio & E. trigs. will be mush by April. Oh, I should say that those are two that I planted in the outdoor 'cold-hardy' garden as a trial.

[cortez753]

My potted Echinocereus triglochidiatus and Pediocactus simpsonii survived uncovered down to -24 F last winter, though with some scarring.

[fanaticactus]

My potted Echinocereus triglochidiatus and Pediocactus simpsonii survived uncovered down to -24 F last winter, though with some scarring.

That's encouraging. My garden Pedio is just inches away from the house on the south-facing side, and I sure hope we don't get down to -24F. I have E. triglochs both in a pot and planted in-ground, so I'll keep my fingers crossed for them as well.

[fanaticactus]

Check out Mesa Garden. They give basic hardiness ranges for all their cactus seeds.

I have been through their website and looked at the list of seeds but can't find any hardiness ranges given. Am I looking in the wrong place?

[Steve Johnson]

Check out Mesa Garden. They give basic hardiness ranges for all their cactus seeds.

I have been through their website and looked at the list of seeds but can't find any hardiness ranges given. Am I looking in the wrong place?

Scroll down on the mainpage to the "Guide to germination-cultivation tips" section, and you'll see the info you're looking for. Not exactly the easiest to figure out at first, but once you learn Steven's system for what the letters and numbers mean, I think you'll find that it comes in handy. And by the way -- not just with seeds, but grown plants too.

[fanaticactus]

Check out Mesa Garden. They give basic hardiness ranges for all their cactus seeds.

I have been through their website and looked at the list of seeds but can't find any hardiness ranges given. Am I looking in the wrong place?

Scroll down on the mainpage to the "Guide to germination-cultivation tips" section, and you'll see the info you're looking for. Not exactly the easiest to figure out at first, but once you learn Steven's system for what the letters and numbers mean, I think you'll find that it comes in handy. And by the way -- not just with seeds, but grown plants too.

Thanks, Steve. I'll give that a try. I just went to the site again. I swear, that page did not show up last night. Thanks again. I've bookmarked it.

[iann]

E. triglochidiatus lives outside here and is not pretty. I'm sure it isn't the cold, but the constant damp (and slugs!) all winter that causes it. Inside a greenhouse they only mark if mites move in.

All my Pediocactus have been down to -15C (5F) without the slightest sign of damage.