When to Propagate Black Raspberries by Tip Layering?

Thinking ahead to this Autumn, I'd like to propagate a few Black Raspberry plants off the parent plant and give them away. Presently, the canes are tied up so they grow vertically and get lots of sunlight. However, later this year I'd like to deliberately arc their tips down into pots filled with soil and encourage them to take root in the pots. Voila! Next Spring I will have new Black Raspberry plants already in pots!

This is the first time I am attempting this.

My question: when should the tips be buried in soil? I was thinking it could be done any time before the plant goes dormant (e.g., October). But perhaps it would be better to give the plant some time before dormancy to get the new roots established (e.g., September).

Anybody in these forums have experience propagating Black Raspberry plants by tip layering? I am interested in knowing when, here in the Lower Mainland, is the best time to bury the tips?

 

I've only done tip layering with other plants, but I see invasive blackberries naturally tip layering very frequently. They will start forming roots as soon as new growth touches soil. Wild Black Raspberries behave similarly; so, you should be able to layer your plants any time after the new growth is long enough to bury a section in the ground.