Can I take large willow branches an put them in water to root? Is this a good time of year to do this?
You can do it that way or better still just take the branch and stick it right where you want it to grow, keep it watered if you get to may dry days. Stick it in a good foot. That's how I propogate mine and I've yet to lose one.
Ditto to MannieBoo - plant direct where you want it to grow, not in water alone. Best is to cut branch sections about half a metre to a metre long and 2-5cm diameter, trim off side twigs, and ram them down for ¾ of their length into the soil. Best time of year is autumn, around leaf fall, but this isn't critical, other times of year will also work.