My first grafts were to wild crabs around the house. I have the following on wild crab: Ginger Gold, Fireside, Keepsake, Macoun, Mutsu, Liberty, Cortland, Tolman Sweet, Gloria Mundi, McIntosh, Regent, Cox Orange Pippin and Wolf River.
Yesterday I went and tagged half a dozen or so crab apples that I plan to dig later in the week. They all have phenomenal shape, all about 8 feet tall with nearly horizontal limbs. The limbs are all 28”+ inches so I assume I should cut those back to 16” or so before adding the grafts?
@tbg9b, how did the apple trees grafted on Pacific Crabapple rootstocks do last summer? In the past I’ve thought about doing that to see how much dwarfing would result, but I don’t have enough room on a city lot to try it.
I have had a couple of customers with large land holdings and a lot of wild crabs that I converted to cultivars. I made 100’s of grafts just using water sprouts and simple splice grafts that allowed me to convert very large trees to new varieties within 3-4 years.
That isn’t what you are trying to do, but the one thing you can learn from my experience is that after you transplant small trees to your property wait for them to recover full vigor and then use water sprouts to create the scaffold branches on your remodeled apple trees.
If the soil your trees are currently growing in isn’t too hard to dig, you can move up to 3" diameter trees (trunks) bare root, but it will take a year or two for them to recover from transplanting. If you try to graft them right away, the grafts will likely either stagger or fail.
Alternatively, you could graft them over and transplant them the following year. That might work more quickly. You could choose the trees that have the most vigorous takes.
Unless some other factor (graft compatibility, etc) is at play, I’d say MF as a rootstock is semi-dwarfing. However, it’s vigor seems to vary a fair bit depending on the variety grafted to it. I currently have only 3 varieties of apple grafted to M Fusca.
Mutsu seems pretty slow growing on Malus Fusca. I’d say swamp crabapple (MF) seems comparable to an M7 root stock in vigor when Mutsu is grafted onto it. I don’t believe my Mutsu tree produced any fruit last year, (with three years in ground). Although it is my tree closest to the water, so that could be a factor in its slower growth. In a year where the lake is high this tree is only a couple of feet from the shoreline, so very wet feet for at least half of the year.
Winter Banana seems fairly vigorous on Malus Fusca. It put on a lot of growth last year compared to my other two varieties on Pacific crabapple. It also seems fairly precocious when grafted with Winter Banana, as it was only 2 years in the ground and it cropped last year. I missed stripping one apple on this tree and I quite liked the flavor when I tasted it in the fall.
I also have Goldrush grafted onto M Fusca and it seems somewhere in the middle of the other two for vigor. I beleve my Goldrush also produced apples in its second year in ground. I can’t remember exactly which apple varieties fruited last summer, as I tried to strip all the apples from my trees that were fruiting for their first time.
I believe some apple varieties grafted to MF can grow to a fair size. Here’s a picture from a BC nursery that sells apple trees grafted onto Malus Fusca:
You can definitely see the very distinctive bark MF has at the graft line of that tree in the picture. On my small MF trees, so far the bark is indestinguishabe from the bark of the grafted variety when young.
When used as a rootstock, Malus Fusca does produce some root suckering, (although not as much as M7). I have an M7 stool bed that produces a lot of root stock, and I’d assume MF would be a good candidate for stooling as well. Some think suckering is a major negative in a rootstock, but I figure why complain about getting free root stock if you can use it.
One thing I might also mention, is that you would definitely want to graft onto Malus Fusca while it is quite young. Pacific crabapple’s wood is super hard, and splitting it for a cleft graft even in trees only 1/4" - 1/2" diameter requires using a hammer.
I’ve been quite happy with Pacific crabapple as a rootstock so far. It’s really too soon for me to say how large the tree will grow if left on its own. I intend to maintain most of these MF grafted apple trees in smaller espallier type form at 6 - 7 feet in height. However, I also plan on letting some grow to much larger sizes on drier unfenced sections of my property (where deer browsing is a big problem). It is my understanding that MF also tolerates droughts quite well, (in addition to having no issue with growing in areas with standing water).
You are in the same climate as myself @vitog, but for others considering Malus Fusca as a root stock I should mention that it is not a particularly cold hardy crabapple variety. Fine for our mild coastal Pacific climate where it originates from, but likely not suited for climates rated below 6a.
Edit:
I also forgot to mention that from what I’ve read Malus Fusca is extremely fireblight resistant.