I managed to get some local mistletoe berries, but also bought from an online seller who was also based in the county I lived in - I hoped it might make them more likely to take. I have a bag of them in my freezer to establish on my trees when I moved to my current garden, but haven't done it yet. You don't need to slit the bark or anything, just spread the gloopy pulp onto the bark - preferably not too thick a stem otherwise the bark is too tough to penetrate.
Been getting mail order fresh mistletoe delivered for many Xmases now and last year, finally twigged about trying to get them taking on one of the apple trees. Chose a bird seed dropping tree to experiment on, and despite doing the googled step-bys, spray daily to keep moist a habitual checkpoint, nothing ever happened. Maybe it was the condition of the berries having been inside and past their best. This year, kept the mistletoe at the front door, and in much better condition for glooping out and into the tree. It’s a hit and hope, but you never know, there’s always next Xmas anyway.
