Caring for a newly planted tree

[wherehaveallthegoodfolkgone]

Hi, I bought a cherry laurel tree and it's been planted into the ground now. I was under the impression I had to water it daily but some of the leaves are turning yellow and falling off. Is this over watering? My friend said laurels don't need much water. Thanks for any advice, pic attached

How to Grow Cherry Laurel | BBC Gardeners World Magazine

Thanks KnittedFerret

Ive recently planted 6 huge 9 foot English laurel bushes in sleepers in my garden..very soon after planting the leaves particularly in the centre of the bushes turned yellow and falling off in plenty every day getting worse..looks almost bare such a shame...what are we doing wrong..the soil is moist looks OK same consistency not clogged but we think the root balls x 8 are dry..we water them every other day, the soil is not waterlogged.. any suggestions greatly appreciated..thank you.

Are the sleepers on paving?