Fresh air versus temperatures?

[Mrs.Green]

I see a lot mentioned about the importance of fresh air, when growing cacti. I don’t doubt that, but what about us who grows cacti in areas whith low temperatures, even in summer? It’s mid summer here but the night temperatures have been around 6-8 degrees celsius ( about 44 fahrenheit) the last week and the day temperatures around 15 degrees celsius( about 59 fahrenheit). This is not unusual at all, it have have been primarly overcast.

Following up on the ‘fresh air’ advice , the windows have been open, in the rooms the cacti are in. ( do note that all my cacti are grown indoors on the windowsills) . This have given a lot of fresh air, also in the rest of the home,not everybody in the household is happy about all the fresh air..or rather the low temperatures following.. ( this morning; 15 degrees celsius in the living room)

But back to the cacti; several have flower buds and off course I would love to see this develop into flowers. I do notice that the buds seems to stop developing in these temperatures and a Gymno developed two ‘mature’ buds but they never really opened up before falling off. ( they stood in the close to opening up state for a week) . Another Gymno only opened the flower when it was considerably warmer for a period and was in direct sun.

So..how important is this ‘fresh air’ regime? Is it ment primarly for those growing in greenhouses, who one would think would be in greater risk of stagnant air, unless its really big? A home were the windows /doors are regularly open on a daily basis, wouldn’t that be enough fresh air for the cacti?

[Aiko]

You will need a greenhouse to get the warmth. Whenever there is a bit of sunshine, the temperature goes up quickly in my greenhouse. Even on cold winter days with some sunshine it could get to 20C. Mind my winters are dull and dark, so hardly any sunshine in general anyway (so not great for any winter active succulents). That might be different for Norway.

My advice for fresh air would indeed be made with a greenhouse in mind. Then it is easy to get both warmth between early spring and late autumn and fresh air throughout the year.

I don't have much experience growing plants indoors.

[Mrs.Green]

Thank you very much Aiko The problem with growing indoors are off course that the rest of the household, me included , don’t want to live in a ‘sauna’, just to keep the cacti happy .. There are at least two months each winter with no sun at all here and there is absolutely no guarantee for sun, the rest of the time either. There can be long periods with overcast and dull weather.

Apart from the epi’s ( cacti) it’s my understanding that there is quite a bit of difference when it comes to needed temperatures , speaking about flowering /opening of the buds? Blooming ( for me anyway) is an essential part of growing cacti, not that I don’t care for the non-blooming cacti but flowers ( that in fact opens up..) is a big part of the fun for me.

I have a Gymno ( uncertain of species) with ten buds now and fingers crossed for these developing into fully opening flowers!

Back to the temperature part of blooming; are there generea /species better to be avoided by me, if blooming is something to hope for?

[7george]

Fresh air can be hot too. If not: provide some air exchange just once a day. The best option is a greenhouse no doubt.

[One Windowsill]

Moving air is probably more important than imported fresh air. Get a fan on them.

Hoyas might be better for a sauna.

[DaveW]

As one Windowsill says moving air is best. Some use large fans in the greenhouse and some just the tiny fans out of computers, scattering a few around the greenhouse. However I can tell you in some habitats it can be pretty windy, particularly when you get the Anabatic and Katabatic winds at certain times of day on a hillside.

https://www.worldatlas.com/articles/wha ... winds.html

On one hillside in Chile, admitted on a loose surface, I was almost blown off my feet whilst searching for cacti. We can never really provide such ventilation in our greenhouses. Many cacti will tolerate temperatures down to a few degrees above freezing at night unless they are from tropical regions. Whilst we can seldom duplicate habitat conditions its surprising what conditions our plants will endure and still flower. Many grow them in their houses at temperatures suitable for humans without any excessive ventilation.

[Mrs.Green]

Fresh air can be hot too. If not: provide some air exchange just once a day. The best option is a greenhouse no doubt.

Thank you 7george To hot fresh air would be really, really unusual here.. I am aware of the fact and as soon as I win the lottery big time, a greenhouse will be ordered! Until then; growing on the windowsills

Moving air is probably more important than imported fresh air. Get a fan on them.

Hoyas might be better for a sauna.

Thank you One Windowsill No doubt a fan would help but with several windows open at the same time, I guess that will help too? I noticed that the hairs on the Epostoas was moving quite a bit In fact I do have a couple of Hoyas, one H.carnosa ( originally a cutting from a longtime ‘family plant’) and a H.kerri. The latter one living in fair from ideal conditions but still graces me with flowers every year. These flowers produce a lot of brown, very sticky nectar. Who is hard to wash off, especially on the curtains.

As one Windowsill says moving air is best. Some use large fans in the greenhouse and some just the tiny fans out of computers, scattering a few around the greenhouse. However I can tell you in some habitats it can be pretty windy, particularly when you get the Anabatic and Katabatic winds at certain times of day on a hillside.

https://www.worldatlas.com/articles/wha ... winds.html

On one hillside in Chile, admitted on a loose surface, I was almost blown off my feet whilst searching for cacti. We can never really provide such ventilation in our greenhouses. Many cacti will tolerate temperatures down to a few degrees above freezing at night unless they are from tropical regions. Whilst we can seldom duplicate habitat conditions its surprising what conditions our plants will endure and still flower. Many grow them in their houses at temperatures suitable for humans without any excessive ventilation.

Thank you DaveW I agree, its amazing how adaptable many of ‘our’ plants are! Apart from your knowledge, I really appreciate the little stories you provide from time to time here! Not long ago I read about the grower who was proud of the ‘fluff’ on his cacti..I would really liked to be a fly on the wall, when the visitor blew on them!

[7george]

Most days in the summer I switch the fan on: we have it integrated in our house, part of the heating system but can run without heat and moves air through all rooms. It is 33 C outside and 31º at my upper level right now.

[DaveW]

Cacti often grow in spite of what we do, not because of what we do!

[keith]

but what about us who grows cacti in areas with low temperatures, even in summer?"

Many cactus grow on mountains they don't like high temperatures night and day. Or near the ocean. try those ones. Copiapoa and rebutia maybe ?

[Mrs.Green]

Most days in the summer I switch the fan on: we have it integrated in our house, part of the heating system but can run without heat and moves air through all rooms. It is 33 C outside and 31º at my upper level right now.

Ough..33 celsius outside..that is way to hot! It’s 12 celsius outside here, a much more comfortable temperature, for me anyway, maybe not so much for the cacti..

Cacti often grow in spite of what we do, not because of what we do!

I think that’s spot on!

but what about us who grows cacti in areas with low temperatures, even in summer?"

Many cactus grow on mountains they don't like high temperatures night and day. Or near the ocean. try those ones. Copiapoa and rebutia maybe ?

Thank you Keith More Rebutia’s are on my wishlist, only have one so far but it rewarded me with a lot of lovely flowers!

[DaveW]

Both Rebutia and Aylostera inhabit similar habitats therefore can be treated the same. However DNA Sequencing has proved they do not belong to the same line of ev0lution, their looks being merely convergence through inhabiting similar conditions. With Hunt's morphological classification (all plants that look alike lumped together) they were all put into Rebutia, but their DNA shows they should never be in the same genus and if separated from Rebutia the oldest generic name then available for most is Aylostera.

In fact most of what we used to call Rebutia's, and many plant and seed lists still list them as such, are more correctly Aylostera's.

Here is the list of true Rebutia's:-

https://www.rebutia.org.uk/rebutia/

Here are the Aylostera's subgenus Aylostera and subgenus Mediolobivia:-:-

https://www.rebutia.org.uk/aylostera/

As you can see most former Rebutia's are more correctly Aylostera's. Rebutia and Aylostera simply looked similar so were previously lumped together on looks alone.

Previously to DNA the genera used to be separated on the basis Aylostera's had a fused flower tube if the flower was sectioned whereas it was open in Rebutia. A good article on the visible differences was in Essex Succulent Review pages 3-6:-

https://www.cactusandsucculentreview.or ... h-2015.pdf

[Mrs.Green]

DaveW; Thank you very much for the links! I have saved those. Slightly frustrating though, every time I think I have a slight grasp of some of the genera, they are splitted or moved to something else! And I have been back in cacti for less than a year..

[DaveW]

Cactus classification is never static Mrs Green and its still a personal opinion as to where you split up ev0lutionary lines into genera and of course with no fossil evidence for cacti those ev0lutinary lines can only be guessed at with the tools and evidence now available. Previously using their morphology (form or looks) and now their genetic make up = DNA.

Also there has seldom been a time when only one classification was used around the world for cacti, two or more running together as at present David Hunt's based on their looks (morphology) and Joel Lode's based more on DNA. Classifications are not mandatory so you can choose any you want. The only thing the "Rules" require is the names be validly published, but they can't shoot you if not so many still use nomina nuda or unpublished names, particularly those found in plant or seed lists.

Generally speaking the Continental Europeans tend to prefer "Splitter" type classifications with many small genera. Whereas the Brits and Americans tend to go for "Lumping" classifications with larger and fewer genera. Neither are probably entirely right,

[keith]

DaveW; Thank you very much for the links! I have saved those. Slightly frustrating though, every time I think I have a slight grasp of some of the genera, they are splitted or moved to something else! And I have been back in cacti for less than a year..:

yea South American cactus naming is all over the place ! I mostly grow N. American but do have a few rebutias- actually one, and a couple Aylostera's.

got a cross of Aylostera helosia and condorensis growing very tiny still , a pot full . I THINK I read they came form the same place so IDK ? orange flowers and red flowers on neatly spined small clumping cactus .

Very worth while group of cactus I should grow more . Also bug magnets so beware....

"but they can't shoot you if not so many still use nomina nuda or unpublished names, particularly those found in plant or seed lists."

haha that's good I think I have a Notocactus around somwhere....