I have asked this question before, but here goes again -- I have been told Spring, Early Summer, Fall. Our new landscaper says Fall, he means early Fall I believe, and stressed doing it when it cools off a bit. It's very hot in Victoria BC right now -- Saanich, actually. He think they will be heat-shocked. This is a question relevant to stratas, which often have quite a lot of cedar hedging. We hate to leave it looking so hairy at the moment, but want to follow his advice. I have consulted web pages and gardening books and they all say different things, I suppose for different climates.
Do it sooner rather than later. Do not do in fall unless you want to look at the newly sheared appearance all winter, without any re-growth having occurred at all.
Thank you, Ron... we'll have to do it this year as our landscaper has not done it yet, but I will encourage him to do it in late August, when the heavy heat and drought is coming to an end and there is still time before winter. Next year we'll do something different.
yes I agree with Ron B if it grows to wide - you esp risk getting all that brown dead stuff inside the thin (normal) layer of greenery --- just have a peek inside your hedge and you will see why the little house finches like to nest in there etc I would not be surprised that your contractor is suggesting "fall" time as she/he is likely very busy running crews on lucrative annual maintenance lawn contracts etc - and is hoping that you'll wait in line. Then again, I could be making assumptions - but that is what I notice with landscapers - this is their super busy time up here in the Pac NW. for future reference, we've always had good luck around end of Feb in to early March with landscapers and as soon as it's not dangerous to be outside with ladders etc (black ice, snow, frost, etc) do all the housekeeping (trim hedges like cedar, laurel) then get a decent mix (remember some tree mulch is toxic, which is fine if you don't have underplantings) of mulch sprayed in ASAP before the spring bulbs sprout too tall. That's what we used to do at our premises here in Vancouver coastal area. nb - note that some shrubs & vines bloom on "old" wood and some on "new" wood - not every landscaper with a truck knows this. I have had a rhodo sheared. I have had a hydrangea sheared. I was annoyed to say the least. The certified arborist fixed some of it.