You can keep them in your spare room. People get confused that their plants have to be kept in the dark, but what’s important for dormancy is the temps. As long as you can keep them in 12C-15C that will help slow things down. Just keep them at those low temps in the window and they’ll be fine. Keep dry:).

If you don’t mind me asking what are the plants your worried about? Echeveria, cactus, Euphorbia, and Haws? This will help when giving advice. What advice I gave was just kinda general:).

Thanks so much Kara! I was hoping that the spare room would be fine, it’s mostly a few cactus that I’m worried about. Last year I had quite a few rot and the ones that didn’t, never went dormant and have some etiolation. I plan to double check which of my plants are ‘supposed’ to go dormant or benefit from a dormancy, such as some euphorbia as well

I could be wrong - and do not really grow cacti, have only few - but I think 12-15*C is too 'warm' to keep them dry. I would try to go down to below 10*C (perhaps 5-8*C? - not above 10) and keep hem dry. I would not keep them dark, regardless the temps.

Unfortunately my options are 20Cish, where I had them last year, the spare room with windows and 10-15C, the basement with no light but slightly colder or outside, which unfortunately isn’t even really an option in the summer, let alone winter. I really appreciate the feedback though!

There are some cactus and Euphorbia that I own that do need a drink every once in awhile during the winter, or else they will loose their roots. I think the easiest way to do deal with this is to keep cool in front of the window in your spare room, and keep your eye on them. I have some Mammillaria that are blooming right now I still give them water, and as much fall/winter sun as I can, and then protect at night. Sounds like a lot, but it really isn’t as long as I keep organized;). Honestly pretty sure you will be alright with the cactus as long as you can keep below 60F. Like I said keep your eye on them;). Pay attention the the top growth.

Things like Sedums and Echeveria don’t really stop growing during the winter, but do slow down. They still need good light and low water.

Are there any succulents you are particularly worried about?

I didn’t really realize until I thought about it, to answer your question, but there aren’t any that I’m particularly worried about killing. I just want to minimize any etiolation and give them the rest they need (if they need it). A couple Mammillaria, some Euphorbia (stellata, inermis, flanaganii) and some fat plants (adenium, boojum, ibervillea and fockea edulis). Should I move my aloes? They didn’t have any problems last winter but they seem to be growing particularly slowly

I have a few small cactus that I can probably get just below 15C. I was planning on keeping them dry this winter, but I wonder if I should water them just a little. All except one are small--like 3-3 1/2" pots. I lost one in the past from not enough water, so I wonder if I should not keep them completely dry. I also don't want to overwater, because I want optimal conditions for them to flower next year. Hard for me to figure out. My Gymnocalycium flowers no matter what.

Jeff, depends what species and what temp/light conditions they will be kept and for how long. Sorry for being so vague but it does make a difference. I have some I don't water for 3 months no matter what and others that will get some water once a month depending on the weather (humid or dry). Tropical cactus can get it more frequently, again depending on the weather and how the are doing (dry soil...)

I have Mammilaria bocasana, Rainbow Cactus (can't ever remember the name of that), and possibly Coryphantha in clay pots in pumice and lava rock, along with even smaller Myrtillocactus geometrizans, and Pilocereus. Light can be anything from sunny window (short daylight hours now) or very strong grow light, or less, I can do whatever. Temp next to window around 60F or higher, or lower under lights. My availability of conditions indoors makes it more confusing for what I can/should do. I'll put them outdoors in late spring. Thanks

Those species are not the easiest to kill with water, maybe the M bocasana and Rainbow (Echinobivia?) could be the most prone to rot in the group. A little drink once a month won't hurt. I have been doing this with mine for years, just enough so that the soil is not drenched and dries quickly. Others might do differently, also depends how long is your overwintering (and how long you keep the light on for those under grow light) . Three months only here for me in SJ. I would not leave them too many months in a row without water at 60+F and strong light.

OK, thank you, that's very helpful. Sounds like they're pretty much all in the same boat, so to speak. I believe the Rainbow Cactus is Echinocereus pectinatus var. rubispinus.

Do you think stronger light may give them more energy to flower?

Sorry got the rainbow confused with Rainbow Burst! The Echinocereus rubispinus is actually very prone to rot and is one that do need to stay dry when cold. This one, I don't water from Dec to end of Feb. Cactus love more light (not always direct sun) but I don't know if more light during dormancy promotes more flower. Cold does though for many species.

Indeed, there is also a "dormant state", not full dormancy, for many during the hottest months of summer. And in the more northern deserts some get most of their rain in winters. so the terminology and growth habits are also likely off when growing these guys in pots outside their natural environment.

While I've got you guys here, if I may intrude on CasualSweater's thread: mine didn't grow during the summer. I couldn't figure it out. As mentioned, they're in pumice and lava rock, small 3 1/2" clay pots, in full sun, usually humid weather. I thought maybe I wasn't watering them enough, maybe every few days to a week, depending on heat, so I moved it up to about every other day in August, and still no growth at all. I fertilized a little earlier in the summer. Any ideas?

I do have a Mammilaria elongota that grew new offsets (not shown).

These are around August.

Jeff, if it's their first season after you transferred them in that media, I'd say it's not surprising. Coming from the seller, they were likely grown in very peat/compost/fertilizer rich soil and going from there to a complete non-organic soil is a trauma and it takes time for them to adjust. With some exception most of my cacti are in C&S soil mixed 50/50 with pumice (so 70-75% pumice final). You might need to fertilize a little more frequently for increased growth in the soil you have them in. Watering more frequently is not going to help so much, most of all if your climate is already humid. You might increase your chance of rot if they are not actively growing. I water no more than once a week in my very hot and dry climate throughout summer and even for cactus of similar size than yours. You may want to try also not to keep them under direct sun all day but maybe half a day (morning or late afternoon sun only). As discussed above too much sun may trigger some dormant state mid-summer. They grow the most during spring and fall, but overall growth will be slow anyway for most cactus.

Alright, I'll make some minor changes and hopefully they'll grow. The Rainbow Cactus is from seed but it's a few years old. However, I did repot it into the new mix in the spring. I also had a very small Myrtillocactus geometrizans that grew well, but in part shade, which might be telling.

I keep all my extra propagations and offsets under a skylight for the winter. 12-16C approximately. They are only given a small amount of water if they really start to look dehydrated (perhaps every month or so). Little water and not too much light keeps them from etiolating and drying out too much.

My other succulents are kept actively growing throughout winter under lights and are fully watered weekly and fertilized regularly. Same temperatures of course because they are kept in the same room!

Other bigger succulents I keep in my office window are given natural light all day long (unobstructed but tinted window) and minimal water for winter- a somewhat small amount each week versus the plants I keep actively growing which are watered twice a week there. They act more like decorations and just slow down until I bring them back outside in the spring.

ewwmayo, that's also helpful. On a tangent--do you reduce length of light (Edit: during fall of course) for those other succulents under light that you fertilize? I've been reducing length of light mainly because there are some plants that could use some seasonality. I might like to rearrange things in the future. I'm doing similarly as you for my succulents. Most of my Echeverias are too small even doing that.

I usually decrease duration a bit, but these days I am adjusting for color and compactness.

Many Mesembs, Crassula, and my only Echeveria are flowering for me now as they have been triggered more based on temperature changes.