Q.Lambert Cherry Tree
My Cherry tree is still in the nursery pot. It has had leaf buds on it for over a month, but has not progressed at all. I also have a Stella Cherry tree which is doing very well, the leaves are unfolding and it looks great. Is there something wrong with my Lambert tree, or is it just not ‘its time’ yet?

Are the branches soft and pliable?
Do the branches snap off and break?
If you scratch the bark is it green underneath?
This is how you can test if the tree is still alive.
Most likely your tree is needing nutrition and moisture to wake up and start growing.
It is the perfect time of year to get your new trees planted.
Here are some links that will help you.
https://www.gardeningknowhow.com/edible/fruits/cherry/cherry-tree-care.htm
https://www.gardeningknowhow.com/ornamental/trees/tgen/tree-scratch-test.htm
https://www.gardeningknowhow.com/ornamental/trees/tgen/watering-newly-planted-tree.htm