What's this on my crab apple?

[Shufigo]

What's with all the lumps and bumps on my crab apple. They don't appear to be causing any problems - just curious.

 

[Native Hunter]

I see the same thing on my NWC crabs. My guess is that it is where limbs have been pruned off and this is how the spots are healing over. If they are healed completely over I think they will be okay.

 

[Fish]

Pretty sure thats what they call burr knots. They can be a liability to the tree. If i remember, borers enter easily there and fireblight can infect there. They are not uncommon.

 

[Native Hunter]

Pretty sure thats what they call burr knots. They can be a liability to the tree. If i remember, borers enter easily there and fireblight can infect there. They are not uncommon.

I see a lot of burr knots around the base of some trees on MM111 rootstock. Today I covered up some on a few trees with dirt because of the issue you just mentioned about it being an entry point for disease and pests.

I had never seen any knots high on a tree until I got some of the NWC crabs last year. Two of those trees resemble his picture above, but I don't see any open places like they look on MM111 rootstock down low at the ground.

When you have them down low near the ground, I think the best thing is to cover them with dirt.

 

[buckvelvet]

Look at the girth of those branches.........my trees are so young, it seems it'll be forever for me to see that, lol..........Nice tree!

 

[Fish]

I see a lot of burr knots around the base of some trees on MM111 rootstock. Today I covered up some on a few trees with dirt because of the issue you just mentioned about it being an entry point for disease and pests.

I had never seen any knots high on a tree until I got some of the NWC crabs last year. Two of those trees resemble his picture above, but I don't see any open places like they look on MM111 rootstock down low at the ground.

When you have them down low near the ground, I think the best thing is to cover them with dirt.

Towards the top of that pic i see one that i would consider "open". I had a box store gala (likely MM111) with those open burs everywhere. That tree was eventually smoker wood.

 

[Native Hunter]

Towards the top of that pic i see one that i would consider "open". I had a box store gala (likely MM111) with those open burs everywhere. That tree was eventually smoker wood.

I saw that one at the top too. I agree, the open ones are not good.

I once read about some kind of acid that people put on those places, but I don't remember what it was called. It probably wouldn't be that hard to look up on the Internet.... That could be a reasonable option for those up high like that. I don't know for sure, because I've not had to deal with them.