Hardy Cacti/Succulents 4 Unheated Greenhouse

Hi Peeps

Looking any advice on cacti & succulents that are more prone to winter distress in a unheated greenhouse (cheap lidl dome type}. I have a few that seem to be doing ok but would like some feedback on types that would benefit from indoor treatment.

I have a blue myrtle cactus (along with a few others) that I now bring indoors because I've heard they are not particularly hardy or they seem not to cope very well.

The cacti & succulents I'm now pampering have been left in a greenhouses/cold frame over winter but looking a thrive rather than survive approach.

All pampered cacti/succulent have been moved to a east facing window that isn't particularly warm but doesn't experience freezing temperatures.

Just to add don't really have positive id's for most of my cacti

All genus/experience/feedback on cacti/succulents that will do well and those that won't.

Zone 8b

Throw names out and I'll research.

Thanks in advance.

 

I find most cacti are quite cold tolerant, but it's a good idea to gather information on each species individually to get a better idea, because it depends where they grow naturally.

The tropical forest cacti do well in the house during winter. I've got a few different ones -Rhipsalis mostly, and they flower in the winter months.
In the summer I put them in a shady part of the greenhouse.
They require more water than the desert species.

If you're keeping cacti in the house in the winter, they will need watering occasionally, because even an unheated room is warmer than an unheated greenhouse. Remember that with cacti and succulents, it's better to give them a good soaking occasionally, than dribbles often. Let them dry out completely between the soakings.

Succulents will let you know when they need water because they will start to shrivvel up.

I don't know if all this is useful to you ...

 

Thanks for the reply.

Yes, I do give the cacti indoors a drink but never more than once a month.

I have a Spider cactus that seems to be shrinking a little will post a pic for feedback.

Cheers

 

Just out of the store.


Current state of affairs. Has been bleached by the sun a bit. Read this particular type prefers a little shade during the hottest part of the day.
Has survived a winter in a cold frame before but totally dry for the period.

 

Which is?

Bear in mind that could well be the referring to the hottest part of the day in Texas or Arizona.
Also if just bought from a store or moved from inside to outside it's not a bad idea to give them a bit of shade in the greenhouse for a few days to allow acclimatisation. I use agricultural fleece over them.

 

Gymnocalycium denudatum Spider Cactus (if I've id correctly)

Had the plant for a while think this is it's second winter with me last winter cold frame totally dry.
This winter inside very stingy with water.
Maybe my mistake flinging straight out in full sun after purchase.
Obviously can't compete with it's native sun but in the summer after about 12 noon-ish (maybe a bit later) a corner of my garden gets sun (when we get it) pretty much all the day.

All the cacti come out of the cold frame/green house when temps permit and are placed in that corner which benefit from a slight over hang so I can still control the watering regime.

Scouring the internet seen pics of these type of cacti still holding a dark green colour and some that are totally bleached. Would like a flower but think the plant is to young.

 

I've found most of the desert cacti I have grown over the years have always survived in a cold frame or greenhouse un heated.
There are a few that like some heat in winter.

Of the cold hardy ones that are OK if dry I would say Echinocereus , Echinopsis, Rebutias that are really reliable flowerers.

I even have a grown opuntias outside without protection if you pick a sheltered spot, they can even freeze solid and still survive.


I dont really grow many these days, I just have the remnants of my collection left

 

Thanks for throwing out names will check them out. The spider cactus pic I posted has fairly unique spines so an id was a little easier than some of the other cacti I own.

I'm sure it would cope with a second winter if kept dry but read it can be a little susceptible to colder temps.

Getting some feedback from peoples experience with different types of cacti is more valuable than reading tinterweb.

 

@pete any experience with Opuntia ficus-indica. Rooted a few cuttings obtained
I'm assuming this is the genus scattered over greece and the med.

 

No but I think that is pretty tender amongst the Opuntias, its more large shrub like, is it not?

They seem to have a wide range and the lower scrambling types growing in some places that have pretty cold winters.
The ones I have tried outside I grew from seed mostly from Arizona and Colorado.

 

They seem to grow more like a shrub. Shall keep my cuttings in the greenhouse.

 

Yes, I have seen it stated at a min of something like 7c but it would probably be OK around 5c I would think if very dry and a bit shrivelled.
The thing I have found is often the problems only show up in the spring when the plant doesn't start to grow and you find internal rot has set in during the winter.

Another problem I find under certain conditions is condensation on the actual plant body, it usually happens at times when we get cold nights and sunny days.
Its tempting to let the greenhouse heat right up on those days but I find that a cactus, which is mainly water, stays cold all day but the warm air in the greenhouse condenses on the plant causing it to run with water and it can cause rot even if the roots are dry.

So I always ventilate on days like that.