David, agreed this is a great place, for the people, for the idea sharing and for so many other reasons! I do find it very interesting to read how others do with there plants in other conditions as well, just curious I guess, but sometimes it can also be very helpful and inspiring, even if one would need to tweak growing methods a bit or simply be satisfied looking at a nice picture. About the climate, well for me it's quite good actually as I hate summer heat
So, I'm not complaining, except perhaps on the behalf of the cactus
.
Thank you Cinta and the method with gravel for sure is a good one. Similar methods are used here as well, not only for cactus, but also to increase hardiness of other plants.
Yes, of course the USDA zone systems has some weaknesses even for you
In Sweden we luckily have our own zone system and it's based more on what is possible to actually grow, rather than temperature averages. Still this also has some pitfalls and by that I don't just mean soil conditions, micro climate factors and so on. Sweden is a small country so many plants that would be hardy, are not very known and have no known zone hardiness. It's widely recognized that the more reliable snow cover up north benefits the survival of some perennials and bulbs, making them growable out of zone, depending on where they originate from of course.
What I think you have going for you Cinta, is perhaps that when winters sets in it probably also gets dry. Frozen ground and snow are dry (from a plants perspective) even if it in reality contains a lot of water. The air also dries up when its been frozen a long time and snow is also the ideal winter insulation. The other thing is how fast it goes when the ground thaws in the spring and freezes in the Autumn. I'm uncertain of your conditions, but here this process is usually long, it can take months or in fact can be an ongoing process through the whole winter. Especially in spring a lot of sensitive plants can rot away. Hard frost without snow cover is rather common here as well. That said there are
some reports about certain species of Opuntia surviving without rain protection in Sweden
