My Dark Winter Success Story

[PresidentKang]

So I've posted before about my dark winter experiment, and I wanted to give you all a final update.

Brief recap: I have a centrally heated apartment, so I can't keep one area cooler than the rest. I wanted my collection to go dormant, so I had to get creative. I used a hole in the wall.... the spot in the wall (lined with sheet metal and vented at the back to the outside) where the A/C unit usually goes. I lined it with plastic and insulating foam, and kept most of my cacti in a closed cardboard box inside the hole in the wall. It took some tinkering, but eventually I got the temperature steady between 38-45. The humidity stayed pretty low, too. The plants went in in December, and I pulled them out in early March. They were in full darkness the entire time. I'm in the Northern Midwest, so outside temps got as low as -15 at times.

I slowly re-acclimated them to light and watered for the first time (very lightly) at the end of March. Other than some minor etiolation on some smaller offsets on an Echinopsis hybrid, my collection made it through intact and looking much the same as before. They plumped up well after watering, and my Parodia ottonis started putting out buds in early April.

Today, the first bud bloomed!There is another one that will probably bloom next week, and two tiny ones that are just starting.

I'm considering my dark winter a success, and I will definitely be doing it again this winter. I'd really like to get the Echinopsis hybrid and the E. subdenudata to bloom next year, and I have a few Mammilaria that I've bought this year that were blooming when I bought them. I hope I'll get most or all of them to bloom again next year, but I'm thrilled with my results so far!

[DesertSun]

Hello! Congrats on your dark overwintering experiment! I have also shared what I consider a success in overwintering mine in a dark room in my house, in which I kept the heaters off all winter and the shutters open, so it could be even colder. We had a mild winter, but it seems that this was enough-luckily- for my cacti to be dormant until spring. I put them out at the middle of March and started slightly watering at the end of March. Only one lost its roots but it didn't rot, so I repotted him and he's doing fine! It seems to me as long as they are bone dry, they can be kept in dark for months, cacti are incredible plants! But I am not going to do it again this year, I will find a more permanent, and suitable place for them to overwinter.

[J-M]

Same results for me. For 6 months most of my cacti were in the dark between 40-54 F (5-12 C). So far a lot of them already flowered or are flowering right now.