Last month, Philip Strange asked me if I had seen any immature catkins yet. They were forming on the birch trees in the UK. The next day I looked carefully at the tree to find this little one (see arrow) It’s about 1/2″ long (1 cm) If I understand it correctly, the larger catkin will form the female flower next spring. Uh, that’s not quite right…the larger catkin will turn brown THIS year and drop off the tree and the smaller one will grow into next year’s catkin. Philip Strange sent me THIS LINK which explains the difference in male and female River birch catkins. See if you can figure it out as I’ve never seen the longer female catkins.
This is how the tree looks in early September. It’s still has plenty of green leaves.
Sept. 20…Leaves of Betula Nigra are still green in September, but starting to show age.
Sept. 10…The mature River Birch cones are starting to fall.
Sept. 10…I see the ivy is growing back. I wonder if Ollie is going to trim it again.
Adventures in Natural Beekeeping 
What I find interesting is to see two seasons of flowers/seeds on the tree at the same time.
I’m fascinated by your river birch. We have a silver birch in the garden, also a nice tree. No cones in autumn though on our tree. Your photos are great. I have ginger growing but its leaves are thin, very thin, perhaps another type.
I’m still unsure about this birch. I’ve never seen female catkins (like the Oregon State University’s website shows examples of) and I’ve never seen the male catkins open up. Aren’t they supposed to do that in Spring?
Thanks for making me take more notice of my trees in detail. I mean I never even noticed that my silver birch had catkins, it is so high up. So went out and took a closer look at this tree, and I found cones among the dead leaves on the ground. The cones quite brown and dry, and the seeds falling away from the cones. I took some photos, might blog about them.
As regard catkins opening up now, I too thought the opening of any type of catkin would be more a spring thing, but sometimes you see trees blossom a bit in autumn too.