Magnolia leaves turning brown/black

Hi, we have a Magnolia Soulangeana and it’s been in our garden for almost 1 year. It’s not flowered yet but its leaves are turning brown/black at the tips. Any ideas what’s causing this?

I’ve recently put decorative bark down, could this be stopping it getting the water it needs?

Thank you in advance.

 

It looks like frost damage to me.

 

Thank you Pete. It dawned on me that we have had late frost this year and didn’t last year by the time the leaves came.

Much appreciated!!