Winter hibernation questions #3

[Steve Johnson]

Hi there. I’m new here but this is the particular subject (dormancy) that I am trying to dial in here in zone 5b.
I hope you don’t mind if I hijack a bit, I figure I can’t be the only person working out future winter care in the middle of summer.

I’m fortunate enough to have a top and side glass sunroom which is heated to 65 degrees throughout the winter. I also keep a handful of tropicals in that room. It has a West/South exposure and on a sunny day in winter, is good for about 7 hours or so of natural light.

What I’m trying to figure out is - am I better putting my cacti collection into true dormancy (above garage, no light, totally dry, 45-55 max temp) or trying to grow all winter long in the sunroom, while supplementing with a couple midpowered LED grow lights? Most of my plants are South American, and most are a step and a half above seedling size currently. Most are also known as slow growers, so I care more about bulking them up right now. But I do worry about water and light needs, and want to avoid elongated growth patterns.

I also have a few agaves and I am in the same boat with them - grow, or neglect and chill.

New to this, so all suggestions are greatly appreciated.

Matt

South American cacti need a cool/cold winter rest to bloom in the growing season -- if your sunroom's overnight lows are consistently below 50 in fall and winter, keep them completely dry. (Hint: Desert cacti won't grow when the daytime highs are below the low 70s.) No light and totally dry may be fine too, but most (perhaps all) South American species will tolerate lows down to about 15 only for short periods.

[7uco]

Thank you Jerry, and thank you Steve.

After hitting the llifle books it appears that the sunroom is going to be a no-go for all my cacti over winter - too warm at night and probably too cool during the day.

So I will banish them to the garage at 40-45 for winter and plan to keep them dry. I appreciate your responses. Have a good one!

[7george]

Jerry is right, cacti are very different even from South America. Those from Brazil or Peru are rather tropical so better kept in the sun room, the same for yang seedlings that tend to grow year-round. "Real dormancy" with winter cold just species like Rebutia, Weingartia, Lobivia or originating from far Patagonia will be in need. I don't like also "no light at all" condition as well. I'd try to find cooler spots in the sun room for such cacti, like along the walls and on the floor. Because 65 F for minimums is quite high and most will try to grow at these temps. If you have several of one species you can try locating them in different places and see how it goes. Also not many South Americans are able to stand colds below -6 - 10 C and maybe you do not have some like this.