New hawthorn whips died back?

I'm a novice gardener and has recently been filling holes in our geriatric hawthorn hedge with new whips (of the hawthorn type ). I'm keeping a close eye on the hedge as I have a lot of new planting in it. I pruned the whips back when I planted them between October and March this year. I noticed this morning that the main stems are brown and dead for around 6 inches and the side branches on some have died back. Lower down the stem is still green. What should I do please?

 

@rebecca harmston
Given the weather we've had recently especially the cold winds I would do nothing at the moment; just wait for spring to really arrive and they should sprout from lower down. Depending where you are and the weather it could be well into May before you see much happening.

 

Thank you. We're in Norfolk so the weather has been all over the place

 

What type of mad scientist are you? I'm a mad plant molecular biologist

 

Looks like you have another cold snap coming before spring gets going. I'm a mad electrochemist, hiding in an NHS analytical lab, with a sideline in collecting unusual/weird plants.

 

Hi @rebecca harmston I totally agree with @NigelJ leave well alone as the weather is to much all over the show and i've lost good healthy plants already which have been replaced with grasses as they're very hardy...best of luck though mate and crossed when the weather pic's up..they regenerate