Q.Blackberry Cuttings and White Fly Control
When is the right time to take cuttings of blackberry vines? Also, how do I effectively control white flies on my berry vines?

Certified GKH Gardening Expert
The fastest way to root blackberry bushes is by taking root cuttings. This should be done in January or February, when the plant is dormant. White flies can be treated with neem oil.
Here is an article or two that you may find helpful:
https://www.gardeningknowhow.com/edible/fruits/blackberries/propagating-blackberries-cuttings.htm
https://www.gardeningknowhow.com/plant-problems/pests/insects/whitefly-control.htm
https://www.gardeningknowhow.com/plant-problems/pests/pesticides/neem-oil-uses.htm