In article , Jane Lumley
writes
In article , Rosie
writes
When's the best time of year to plant a clematis?

Autumn, but early autumn, IIRC. The idea is that they don't need quite
so much water - a new plant planted in late spring will need daily
watering for six weeks. Early spring (but not in frozen ground) is next
best.

I guess it depends on where you live. Here, in the Lake District where
the rainfall is quite high even during the summer, it's not such a
problem. In drier areas you might have to water regularly anyway even
when the plant is established.

Plant it well & add a pipe going down to the roots (fill it with stones)
so you can pour water straight down to where it's needed.

Some varieties will tolerate drier conditions than others too. And non
of them like being waterlogged during the winter. As has been
mentioned, container grown plants (not just clematis) can be planted at
any time of the year provided the ground isn't frozen. In my
experience, early autumn or spring - but when the ground has started to
warm up is best.
--
Rachel
Clematis Web Site
http://www.ukclematis.co.uk/