Strange growth on new tree

I received my order from Century Farm Orchards yesterday. One of the trees came with the growth visible in the picture below. Any idea what it is? I’m a little worried it’s black knot, in which case I’ll bag up and throw out the tree.

What fruit tree is it?

Remind me of fire blight more than black knot but I could be wrong.

also possible it may just be a sealant of sorts.

contact the vendor if they have been using sealants, and if not, you might want to email them a pic of your purchase.

I think the black stuff is a sealant. But what I’m talking about is the growth itself. If you look at the second picture, you can see that the graft union is a few inches above that whole messy situation.

Whatever it is, I would either throw it away or prune it off (if I could use the rootstock for grafting).

Either way, I hope the nursery will send you a replacement.

Why would you use sealant on it if it is not the graft union? What you’re calling the graft union just looks like new growth to me.

Fair point, Drew. Part of me feels like that was a failed first graft.

Yeah I’m not sure? We need comments from more experienced growers.

You will find that to be masking tape and a black sealant of some type. That is how he grafts all his trees. Personally I would be more concerned with the large swelling at the graft location in terms of long term health of the tree.


I’m just guessing but It looks to me like a pear tree which doesn’t get black knot only Plum and Cherry get anything like that to my knowledge. The black stuff is tanglefoot so the knot is not actually black. That egg looks to me like swell from the graft tape being on a bit long and the roughness is from the type of tape he used which debarks a bit when you pull it (because it’s sticky). Roughness can also occur and does frequently where the rootstock meets the scion wood and causes callousing. May even be some of the tape still on there as that type can be hard to get off. Again I’m just guessing but that’s the way I read it.

Yes, I think there is some confusion where the graft union is. As Turkey points out it is the large swelling. The branch coming out above that is just because the tree was headed at some point. Maybe they had extras and wanted to not have the tree get too big to sell the following season, so this last spring they headed it.

The growth looks like a burr knot. It is more common on some rootstocks. I have had several stocks with such knots and they did fine, but it can be a place more prone to injury/disease. I would send them a picture and see what they say about it.

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Maybe a burr knot that formed under the tape/sealant. I think the tree will be fine.

That tree was bench grafted with a whip or whip and tongue or cleft graft. The top portion is the scion wood from which a bud broke and gave you the tree. We cull any trees that develop a knot like that one and do not sell them. We might have 2% of our bench grafted trees develop those knots. I have seen those knots “girdle” a tree over time.

All right. Thanks for all the input. Scott, I’ll send them an email as you suggested. For now, as long as it’s not diseased, I’ll just see how it grows. Thanks.


especially if the graft point of contact wasn’t optimal and/or the sizes of budwood and rootstoc are radically different. The callus literally has to grow and ‘crawl’ all over the inactive surfaces, in its quest to form a cylinder of cambium. And if warped/expanded deadwood or even the hardened sealant were getting in the way, the callus will have to crawl over those too. Hence the knot.
windy conditions aggravate, as shearing occurs mainly at the weakest point–the graft union, and this further adds to the ‘disorderly’ callus growth

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If I had a graft union that looked like that, I’d be inclined to think that it had become infected - probably by me - with Agrobacterium tumefaciens, the bacterium which causes crown gall.

I see knots like that resulting from compatability issues and not symptomatic of a bad graft or disease.

Some cultavars like jonagold are prone to develope them. I see it most on triploids when grafted to dwarf rootstock especally m26.

What is the variety / rootstock?

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exactly what I was thinking…crown gall

M111 Lady apple

I should add that I’m not discounting juju’s mention of disorderly callous growth. I had grafts on plum look very similar to that. I don’t think I’d bother with it though. I have a feeling the nursery will want to replace it either way.