New Hawthorn Hedge

You're more knowledgeable than I am, but my gut instinct would be to leave them for at least a year. More leaf surface area means more opportunity for photosynthesis which means stronger plants with stronger roots in reckon.

Hawthorn is very resilient so once established a bit, I reckon then you can give it almost as severe a haircut as you like to encourage it to bush up.

 

If you cut them they will put out more branches and thicken up but you can get a bare bottom or you could leave them for a few years and then lay them which will thicken them up as well but you will get a thicker bottom to the plant
some people when they plant bare roots they will cut the tops off then but it all depenes on what you want

 

Did you prune before you planted? If not do so now, not too much but about a third off the most strongly growing branches. It will encourage bushiness. Then prune again towards the end of summer.

 

I don't think anyone on GC wishes our woo a bare bottom

 

Some excellent advice in this link @wiseowl

Hawthorn Hedging - How To Clip a Hawthorn Hedge

 

I was thinking of Woo's hedge, as to hedges around here you can walk though the bottom parts of them because they have not bust out at the bottom just stalks then alot of bushyness at the top were the hedge trimmer trims

 

The local estate workers have just cut a long length of hawthorn hedge down. Next time they'll lay it.



This is how high it was before cutting

 

It will grow back thicker than before.

 

They should know what they're doing as they planted a new hedge that was subsequently used for the National Championship a few years ago, an ex-neighbour helps organise these competitions, and sometimes gets in the top 3.