I divide my cactus collection up into three categories based on their winter growing conditions/dormancy requirements. The thread title is one of these categories. By it I mean it contains cacti that need cold but above freezing conditions for best growth and bloom the next year. I mainly used the information I got from The Encyclopedia of Cacti on llifle.com [url=ttps://www.llifle.com/Encyclopedia/CACTI/]ttps://www.llifle.com/Encyclop...[/url] But I used other information obtained from books and Internet searches.

I have a friend that has a few commercial greenhouses that allows me to bring my "pet plants" to his greenhouse for winter storage. The greenhouse I use is kept above freezing so the pipes don't freeze, but just barely, except for sunlight heating. He has a roll out tray which he rolls outdoors when it is above freezing and not raining/snowing. These are ideal conditions for these plants. They don't get any water at all from early to mid October till it warms up at night sufficiently, which will be in April. I bring the plants back to my home when he needs the space in early March. At that point I bring them into my unheated garage and bring them outdoors when dry and above freezing.

I took a photo of my plants yesterday while they were outdoors.


The main reason I took the photo was because I saw a bloom opening up on one of my cacti which I bought last July from Miles2Go. I have three of them in one pot, and one flower was opening up in the bright sun yesterday. I ended up misting all of my plants today because it was warm and will only go down to 46F tonight and be warmer tomorrow. I just give the plants a tease for the first waterings. I may mist them again tomorrow.

Turbinicarpus schmiedickeanus ssp rubriflorus is the plant. Here they are as received July 13, 2023.


And here they are after their first watering since potting up. Photo taken July 29, 2023:


Here's yesterday's flower. It isn't fully opened. The spines are blocking it. This bloom shows up before they been watered. Last water was in October. I kind of don't take credit for this flower since they were grown by Miles Anderson of Miles2Go up till July of last year. If they bloom for me next year, then that is after a year of my care, then I can take credit for it.


Another plant in that box has a whole ring of buds. It is a Eriosyce (Neoporteria) senilis. I bought this plant from an expert on these plants, Fred Kattermann, in 2007 while a member at the Connecticut Cactus and Succulent Society. Fred is a member there and lives fairly close to me in Sussex County, NJ. He ended up donating his entire collection of cacti to a desert museum which I forget right now. I'm ashamed to say that through my neglect I let the plant get a misshapen growth band, and the plant sent out an offset. Not typical growth. And they will always be there. Bummer.

Yesterday's buds:


Last years flowers on May 2, 2023:


The other plants in this box are:
Chamaeocereus silvestrii
Copiapoa humilis
Echinocereus fasciculatus M2G
Echinocereus rigidissimus M2G
Echinocereus rigidissimus ssp rubispinus L088 M2G
Echinopsis huascha var. purpureominiata M2G
Epithelantha micromeris M2G
Lophophora diffusa var. koehresii
Maihueniopsis darwinii CCSS
Mammillaria haageana HD 1
Mammillaria senilis M2G
Sulcorebutia arenacea
Tephrocactus articulatus var. papyracanthus
Thelocactus bicolor ssp flavidispinus M2G

I can confirm the first plant on your final list needs a bit of cold for proper flowering. Or at least the plant I have rarely flowers, given our mild winters (min. 46F), but the parent from which my cutting came flowered very nicely in a cooler inland location.

Mamm. senilis does not require cold to flower in abundance. My plant puts out quite a show in the spring. Not that you need change a thing, just noting this observation since I'm in a place where the experiment is possible.

That Tephrocactus does quite poorly here, I think due to insufficient heat.

I had the Eriosyce and it did well here for several years in a very small pot. The flowers were nothing near that exuberant, though. It is a spectacular show.

That is an interesting list. I look forward to getting to know these plants better when they are doing their thing.

Your friend is generous to help out with the greenhouse. These connections are valuable.

I took a couple of photos of my Eriosyce (Neoporteria) senilis blooming today. Same time as last year. I just watered them deeply two days ago. Prior to that I was giving all of my cacti in this storage category small sprays to get them woken up. I did this over the past two weeks or so. I had to watch the night time temps as we can still get frosts. But this week is warm (55F) even in the nights. High 70's-80 in the day.

It is in a 5 inch pot and the plant is 10 inches tall today.

Today's photos: