Included bark/structural question on a crepe myrtle

[Mossy Dell]

We need advice here in SW VA on our Natchez crepe myrtle with four trunks. It was about 6 feet tall when my wife brought it home 4 years ago and is now about 12+ feet. From the start, I've been worried because its structure is two pairs of trunks that are joined at their bases.

One pair is joined lower, the trunks share a wide base, and they have a bark ridge between them. The pair that concern me, see photo, are joined slightly higher, and it looks like an included bark situation. I am worried that, when the tree is big, a high wind is going to split one trunk or both at the base.

I've seen that breakage often with co-dominant trunks on red maples and of course Bradford pears. I've never noticed it with crepe myrtles, but I'd guess the fundamental things apply. Is my hunch true? I have seen some bases on crepe myrtles that would be intolerable on a big shade tree. But we are north of their main growing area, so there aren't as many crepe myrtles here to study.

Second, if I cut one leg, how? It'd be the one to the right in the closeup, which is at the rear of the tree and closest to the porch. I presume I'd cut at a 45 degree angle, going upward toward the start of the opening between the trunks. Cutting off a leg would also allow me to shape the rest of the tree better, but it would create a large pruning wound.

Finally, would reduction cutting that trunk's canopy for 1-2 years be best, to subordinate the trunk to make a lesser eventual wound in relation to the whole?

I am not a trained arborist but an amateur, a guy who loves trees, and I don't know how to weigh all the future risks and tradeoffs here.


My question is about the pair on the right.




Closeup of their base.

 

[cookies]

thats normal

 

[Mossy Dell]

thats normal

I'm sure it's common. Is it the same risk in a crepe myrtle as in a Bradford pear? These Natchez are small trees but I think I read they can get 25-30 feet. That'd catch wind and break a Bradford.

 

[cookies]

I have one in my front flower bed thats 30+ feet tall with the same growth. So far its survived several hurricanes. What your going to hate is the root system and yearly leaf drop. Their roots are predatorial towards other plants/flowers/bushes etc by targeting their roots slowly killing them up to 20 feet away.

 

[Mossy Dell]

Dang! Well thanks for the warning, cookies. I had no idea.

 

[Seachaser]

I would cut everything at about chest high. They bloom more and are prettier. i just pruned mine today.

 

[Mossy Dell]

Well, I've already limbed it up above chest high. There are definitely some reduction cuts I could make to that trunk's canopy though.

 

[Seachaser]

I’m talking about topping it.

 

[Mossy Dell]

Thanks, Seachaser. But to me, topping would ruin its lines. Also I’m trying to get it to 8-10’ before it branches so I can see through it from inside.

Since crapes bloom on new growth, you can get the bloom flush you mention from light tipping/rounding over or reduction cuts.

 

[cookies]

People here plant the largest versions then start toping them at about 12 feet in height(folding ladder height lol ). It turns them into a yearly hassle of having to re top them every year or they get lanky weak branches for several years resulting in a deformed crown. Every winter they look terrible with a bunch of stubby cut branches on a couple trunks. If left uncut and its healthy it will profusely flower very year for about 60 days. The bark is pretty cool because around the 3-4 inch trunk diameter it will start peeling every year like cinnamon then flake off keeping itself clean of parasitic moss/lichen/mold/funguses etc. The topped ones do not shed their bark as heavily resulting in parasitic buildup or even diseases. They can suffer from black mold and that brings spider mites, powdery mildew and moths if the canopy grows too dense. I tend to thin out the canopy to let some light through to the ground about every other year to keep mold down on the house and reduce the rot in the mulch bed under it. The only thing I have found to actually survive in its shade is monkey grass and even it struggles due to the root system attacking it.