As already mentioned, winter pruning, raising crowns on trees etc.
Most tree work is best done when they are dormant as Stewart has already said.
I used to do alot of work on Building sites (new build) and we always planted trees in Winter (bare root).
Mainly because it was cheaper, easier to plant and you dont have to water them.
Dont get me wrong, not all lived and sometimes you may only get 50% take on the trees.
The diffrence in price between buying bare root and containerised is alot, so the risk of some not taking is outweighed in the cost diffrence.
Years ago when i worked for a Landscape for on the Maintenance side, we always helped out the Landscapers and Tree boys in the winter.
Theses days im too tied up in Management, planning for next years program, Doing audits of written off kit , so i can buy new kit ready for next year.
Organising Sub contractors for Tree works.
Pricing up tenders for Extra works, new build Landscape works, Tree works, Fencing.
Soon i will start to advertise for temp. staff for next year (about Jan/Feb), interviews etc .
At the moment im picking up a Winter gritting round of about 17 sites for another Manager.
This can take up to 6hrs to get round, very Lucrative for the company and me.
So its People like me that during the Winter keep the NHS sites clear of ice and snow, retail parks, offices, banks, Railway stations etc.
About 3000 sites Nationwide as a company.
So thats what i do during the winter.
In some ways busier than i am during the summer.
Hence why recently i have not contributed much on here, simply because im so busy with Work.
Hope Everyone had a Great Christmas and wish you all a Happy New Year and All the best for 2011.