This year I went with Budagovsky 118 rootstock which should be hardy for my zone four, good for my poor soils, and vigorous enough to take advantage of our very short season. All those factors tend to dwarf our trees. The usual root stock of choice here is baccata but that one does have compatibility issues with some apples. For instance last year none of my prairie magic took on that.
Is anybody here using B.118 in zone 4 and below? It is very hard to find much actual data beyond “extremely cold hardy” and some second hand references from vendors claiming zone 4 and even 3.
Currently labeled 4a here, used to be 3b. Still is 3b since we routinely go lower than -30.
I’ve got a number of trees on b118 that have seen plenty of temps from -25 to -38. The -38 was recorded at my house which sits 30’ higher than at least some of my orchard trees, so I assume it was -40 or lower for some of my b118s.
I can say the same thing for M111 however…and my trees on M111 aren’t as prone to “leaning” as are those on b118. This is a very windy area however.
I think the key to hardiness for most any rootstock is to be fully dormant before it hits -20 or lower.
just grafted 4 different apples onto 10 of these rootstocks. liberty, burgundy. Clark’s crab and state fair . going in the ground tues. ill post how they do.
There’s a company here in Canada called Hardy Fruit Trees that markets trees for Zone 1 and 2 and I believe they use mostly B118. I’d bet money it’s extremely cold tolerant and certainly good further than Zone 3.
I emailed them to check, they say they are using bacatta and dolgo which makes sense; few things are known to survive zone 2 and those two are certainly known contenders. Rescue would be another candidate.
Bacatta is probably one of the most used rootstocks here in Alaska but it has proven incompatible with several varieties. Apparently it has to do with apples that has no crab parentage but there could be more going on than that. B.118 just seems like a good candidate for our poor soils so I have my hopes up.
Time to raise this thread back from the dead. Muahaha…
I’m still very happy with B-118. Last year we saw some pretty low lows, I don’t recall what was at the house but I’m pretty sure we saw -30f. On my way to Anchorage I go over a river valley that flows from the Knik glacier. There I recorded the lowest temperature I have ever seen around here, -39F. Long story short the two large trees I have on B118 came through with flying colors. The rootstock seems well suited to our sand/rocks soils. The trees push up a good amount of growth in our super short growing season.
Funny enough last year I didn’t get to plant any of the 2023 grafted trees, I ended up planting other stuff and either gifting or selling the saplings. This year I’m planting a 2024 grafted Chestnut and Zestar, they should be good test subjects.
Also a Root stock that produces high levels of electrolytes in the sap tend to do better in cold climates. the higher the electrolytes the colder it can tolerate, kind of like antifreeze for the cellular protection against freezing.
(I stand corrected, it’s not a higher level of electrolytes, rather it’s a lower level of electrolytes that improve cold hardiness of an apple tree and maybe other fruits too. i left the first part of this post unedited as other comments are based on it.)
I have no idea if there is significant variation in rootstock dissolved solids in sap (there probably is)
But the argument that saps higher in dissolved solids (mostly sugars) don’t freeze as easily isn’t controversial at all. It’s an extremely common adaptation amongst cold weather animals (amphibians in particular) and in plants
all 5 of my apples are on b-118 rootstock and 2 survived 3 days of -40 and slightly colder with 0 winter kill above the snow line. the other 3 weren’t planted yet. they are all planted on mounds above my shitty clay soil.
This guy is from Canada, i had `discussions with him about cold tolerance of fruit trees, he told me that electrolytes were key in developing a cold tolerant cultivar. i believe he’s a plant scientist, he is very knowledgeable Momento Malum
unfortunately i do not know of research that states my claim. but he might.
I live in a mountain valley, short-season site (Montana). Although USDA now has us rated at zone 4, I think we’re really in zone 3. Winters of 22-23 and 23-24 both had instances where we had around -45F. I have planted quite a few apple trees on Bud 118, but have not found it to be a good choice for here. At least with younger trees, there seems to be a lot less vigor and more winter dieback with trees on B118 than with trees on Antonovka. I don’t think I’ll be using Bud 118 any longer.
