On 8/17/13 9:10 AM, islayhawk wrote:
A garden I have started to tend has a row if tightly spaced evergreen
holly trees growing along the perimeter. The owner has asked me to prune
them back to form a tidy hedge. What is the best time of year to carry
out the pruning/clipping

islayhawk

I would wait until about 2-3 weeks before the last frost might be
expected. Pruning promotes new growth, which is quite tender to frost.

Obviously, you don't really know when the last frost will occur.
However, you can get a good estimate of the average date of the last
frost and prune 2-3 weeks before then. New growth will start in about
3-4 weeks.

If you do not get frost in the winter, prune holly at any time.

--
David E. Ross
Climate: California Mediterranean, see
http://www.rossde.com/garden/climate.html
Gardening diary at http://www.rossde.com/garden/diary