Ten days ago I took some cuttings from a rosemary bush and put them in
a pint glass of water on my kitchen windowsill. I didn't add rooting
powder to the water as the pot I have says not to be used for edible
plants. According to the instructions (which I found on the web and
can no longer locate), in six weeks, the rosemary should have rooted
and be ready to put into soil.

It has since occurred to me that I don't really know what to look for
(spot the clueless newbie). I was vaguely expecting something that
looks like roots in a biology textbook. However, the ends of the
cuttings are becoming covered in a fine cotton wool-like substance. Is
this mould? Should I rinse it off? Should I give up on this batch and
take more cuttings?

Any advice that you can offer on making my cuttings successfully grow
would be great.

Thanks in advance,
Kerry