On 07/09/2016 20:12, Nick Maclaren wrote:
In article , Dan S. MacAbre wrote:
I'm looking at a Rosemary bush in the garden which has got a bit scruffy
this year. I don't want to accidentally kill it off, because it's nice
to have fresh Rosemary available, but looking at the stems, I'm guessing
that it doesn't grow from old wood. Or does it?

No. And it has anything from a 5 year lifetime upwards, depending
on the conditions, garden and God knows what. It layers fairly
easily, so put half bricks on top of a branch or two (burying some
not-too-old wood) and leave them for a year or so. When well
rooted, they can be cut off (and transplanted if wanted).

I find that a lot of rosemary grown in the UK is infected with some sort
of fungus that kills off a few branches every year - making it
effectively self pruning. The leaf nodes on the affected branches show a
sort of white fur not unlike woolly aphid but with straight fur. Shortly
afterwards the stem goes brown from the tip and dies back. I prune them
out as soon as I spot any signs of trouble. YMMV

Even with good drainage and a south facing dry spot it always seems to
be clinging on to life rather than thriving up here in North Yorks.

Larger gnarled dead pieces of rosemary look ornamental in a fern garden
- fortunately as you say healthy bits can be rooted down easily.

Regards,
Martin Brown