Avoiding black knot

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RobinVH
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Joined: Sat 08-Jan-2022, 19:52

Last year, we had to pull out a plum tree infected with black knot. I'd love to plant a new plum, but multiple trees in the neighbourhood have struggled with black knot and I don't want to put in a new tree only to watch it slowly die. Any tips on how to protect against black knot or should I look at other types of fruit trees like apple and pear?
jack oostenbrink
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Hi Robin, I have noticed that the European plums are much more prone to black knot then the Japanese varieties. Especially the Italian prune plums (my favourite) seem to get it worst of all, and I find myself removing up to a 1/3 of the branches every year as I try to manage it. The Japanese varieties ripen earlier, are sweeter and juicier, but not as good for canning and not freestone. If opting for a Japanese variety, Shiro will produce loads of yellow fruit that is plump and juicy and very reliable, Santa Rosa is a good pollinator for it. As far as I know, there is not a variety that is truly black knot free.
You can reduce the infection on a tree by immediately cutting out the black knot when you see it, and by thinning the tree and opening up the structure as much as possible on a yearly basis. All cut branches should be burned to reduce the chance of reinfection.
Pear or apple are probably better options if you don't want the hassle of managing the black knot.
RobinVH
Posts: 5
Joined: Sat 08-Jan-2022, 19:52

Thanks for the suggestions. Maybe I'll start with apple and pear, then build up to trying plum again, but with a different kind.
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