No, birch will bleed if you prune now, I would do it in August or around that time

Thx I'm so mad at myself for forgetting to do this earlier.

You can do it now if you want - the bleeding is just freely flowing sap and is more cosmetic than harmful. It tends to be of much more concern and disturbing to the one doing the pruning than it is to the tree itself! If the tree was prone to BBB (& river birch are not), then there would be an end of April deadline for any pruning until mid fall or later.

I would also have you consider that those multiple stems/trunks are a natural occurrence with many river birch and a somewhat desired trait. Wholesale tree growers often encourage that look deliberately by planting three (or more) seedling birches together in a single planting hole. That's what the situation is in your last photo - three separate trees grown together.

Excellent info Gardengal48. I appreciate it. That does change my mind. I'll prune one stem off instead of more.

Your clump river birch isn't going to look like the Whitespire birch in the second photo unless you cut out the largest trunk and then choose the three (or however many you want) most similar trunks in height and caliper to remain. That tall trunk is too dominant that the others will probably never catch up.

Yes it certainly looks like it wants to be a single stem tree. Never seen one in person though.

In the first picture, the largest leader on the right and the one opposite the large main leader, could be left and you would end up with a fairly balanced 3 stemmed tree. I've seen plenty of larger 3 trunk birch that has one trunk twice the diameter of the other two, yet looks just fine. So I know it's possible.

Cutting out the rest of the extra stems will help reduce competition for moisture and nutrients. If for some reason this doesn't work, you can always take out the other two later.

Here is my river birch. I would prune out some of the smaller shoots coming out from the center in yours at the appropriate time of year. : )

This tree was planted four years ago and was about 12' tall. This photo was taken from inside the house. The tree is at least 20' now. I love it! I think I need to expand the bed it's in though. Looking a little off balance. There are groundcover plants in there, they are just new though.

Look at this gorgeous bark!

Looks awesome! That's the look I hope to achieve. I just pruned 3 of the stems.

That looks good. As mine has grown, I've pruned off the odd side shoot to allow me to go under easily with the mower. You may wish to do that at some point in the future with the far right lower branch, but not now. : )

Prepare for it to put on some serious growth, as it gains size. To be honest, mine is probably too close to the house, but I love huge front yard trees! I may not be saying that in 10 years. Lol.

Mine is a lot closer to the house than yours haha. I've seen neighbors with their's planted near the house like mine so figured I'd give it a shot. Worst case scenario I'll be doing a lot of pruning.

Looks good! I'd have done the same thing, except the lower right branch would be gone already.... but it's your call, not mine. :-)

Thx so much for pointing that out Kaillean and Bill. I didn't even notice. Gotta love this forum. I'll cut it off soon.