It's late summer and you know what that means! Time to tip layer your brambles. Or at least your black raspberries!
What am I talking about? If you have red raspberries (or a cousin like the golds), they send up suckers each season and that's how they propogate.
Not so with black rapsberries. They send up a new cane from the original crown, but they do not send out suckers. So they do not rapidly multiply and take over your yard like the reds. Oh the never ending berry growth is a beautiful thing...
So if you want bushes in any other location or just want to increase the number of plants you have, then what do you do? It's called tip-layering.
If you let a black raspberry cane grow, it will grow and grow until it tips over and touches the ground. Naturally, the cane will start to root at the tip and start a new plant. But this may not be where you want it, or the tip may not contact the ground and no rooting will happen.
You can encourage your plants to tip root, by bending the cane over and burying the tip in the ground. But it won't stay there. :)
I'm using a large stone to hold my newly found wild black raspberries down (the tip is actually to the right of the rock, not smashed under it.) I couldn't wait until late summer, so I started mine a few weeks ago. I checked on one of them the other day and saw roots beginning to form. Wahoo!
By this simple step, I should be able to double the number of plants that were in my yard. Now if I could only quadruple them.....
I've read you can do this with purple raspberries as well. I have purple royalty so it's more of a red than a black and doesn't respond to tip layering.