I removed FK last year without ever getting a ripe fruit. It is interesting that Splash at your location and at mine hasn’t been infected. I like the taste of Splash and hope I can manage BK on it.
I’m hoping that we can piece together a smaller group of Black Knot resistant varieties or an least some that the level of infection is low enough to be managed without totally destroying the tree. It might be that some varieties are okay in one area and not in another.
@coolmantoole. Maybe Marcus will see this post and comment on his varieties without Black Knot.
I always like seeing a no Black Knot location. What is your thoughts on why you have escaped it? Do you think it is the varieties, location, or management practice etc.?
So far I have not had much black knot trouble on my plums. There is a little on Mariana. I haven’t seen any on the various improved Chickasaws so far, but I doubt they are immune.
I have been fortunate not to have black knot in my plum trees, which include Shiro, Satsuma, Green Gage, Castleton, and Rosy Gage (a supposed BK magnet). I also have various grafts of other plums and pluots attached to these mother trees, some from people chiming in with BK problems on this thread. The two J’s are in full sun all day, but the E’s are in an area close to a thick forest, and while they get decent overall sun exposure, they get virtually none from the east. Most trees are at least 5 years old.
My property is surrounded by a mature oak tree forest, with no native plum or cherry trees. This is probably the biggest factor of why I am lucky, so far.
I think, like @Auburn said giving your location/state where you are is helpful.
Being in zone 6 here in Central MA is different from zone 6 in AZ or MN. Local climate likely affects disease pressure.
I think it’s all three. An ounce of prevention is worth a pound of cure.
I’m a strict believer in gardening smart. Too many people invite bad
things to happen to their orchards.
I ran into black knot for the first time this year. I even posted a thread to verify its identity because I had never seen it. My methley has it pretty bad and i was told it is k own for getting black knot. The only other variety I’ve seen it on this year is emerald beaut which I found a single strike.
I’m curious what would happen if you painted the knotted area with white latex paint similar to how tree trunks are painted. Would it encapsulate the knot and prevent it from releasing spores?
Some of the ones mentioned above had had knots for me…
I have had some knot on Satsuma, I would say it is better than average but still not highly resistant.
Rosy Gage was my worst ever, the only one I took out - every branch was knotted.
Pluots generally I would call bad by default, I have had lots of knot on many pluots. Maybe some did not but I can’t remember any now.
I do think Middleburg is relatively good for a Euro, it gets much less knot than the plums around it. French Prune also does a bit better than average; it did get one small knot this spring.
Being immune might be asking a little much, all plum trees can probably get it under certain circumstances. I expect highly resistant is about as good as we can do.
I have a Castleton on Krymsk 1 that hasn’t got any black knot yet. Rosy Gage has been my worst. I’ve cut out the same three large knots on the main trunk for several years now and they always come back especially on the outer edges. This year, the tree is loaded with fruit so I’ll probably try to keep it going as long as I can.
I’m in zone 5A so barely tolerable for plums at all. It doesn’t stop me from growing them; I just accept that I’ll miss out on fruit some years due to bad freezes. I grow toka, superior, black ice, Coes golden, Italian, Kirke’s blue, Mirabelle de Nancy, bavay greengage, schoolhouse and long john. THUMBS UP for these for cold hardiness. They all survived last winter, which had 3 straight days of -55F! have never seen black knot on any of them either, but I do see it on trees around here occasionally. A friend recently lost his Mount Royal to BK. I’m in my 4th year of growing.
-55! That doesnt sound like zone 5a. Im glad youre having success though.
Sounds more like Anchorage Alaska.
I wish I can tell you which of my plums are BK tolerant. I can only tell you what to avoid. Mostly E plums. Today it is windy. Wind has been blowing branches around fir hours.
The good news is I’ve had clear views of underside of branches and inner areas of each tree. The bad new is, I’ve several ugly BK!!!
There were several BK on Mirabelle Parfume de September. I removed what I could see including a couple of good size limbs.
Thanks. It would be nice to have a clean list but reality is different. For the last four years my Fall Fiesta didn’t have any BK but I was out looking and found one knot on it. This pluot is large and ripens later than my others so I had high hopes for it to be disease resistant. I am willing to remove a few spots but when it looks like I will have to almost remove the whole tree it is time for me to consider removing the variety. Black knot to me is like fireblight in that it is hard to figure out.
-my E plums were planted in full sun with enough room between each trees
- my J plums planted in partial shade with tighter spaces and branches crossing
E plums still get far more black knot than J plums. If I were to switch the locations, I probably would have removed at least oneor two of my E plums by now.
I also spray copper at dormant once or twice a year to these trees. Imagine it could have been worse without copper.
yes, looks the part.