Advice on newly planted trees

Last November I planted a number of larger trees(10-18'tall) that I bought from a nursery.I think I did a good job planting them,but as spring comes i'm excited and nervous to see if they survive.Any tips or advice of what to do as spring starts to give them the best chance of survival.I'm located in southern Ontario and planted:sycamore, green-spire linden,blue and white ash,corkscrew willow,weeping willow,poplar and a pair tree.
Any advice greatly appreciated

glen

when the buds start to swell give the trees a top dressing of compost and light mulch.

Make sure they are well staked.  Trees planted when they are already tall have not developed the roots to keep them stable. 

Winds will rock the root ball if they are not well staked, and the wind has more of an effect once the tree is in leaf.  Every rocking will damage root hairs at microscopic level even if there appears to be no harm done.... and this will reduce the surface area of roots available to absorb water...

Thanks guys,I would not have thought about the root ball shifting as their root balls where 400-800lbs-good advice.I was thinking off using composted pine mulch-what do you think?

Wow 400-800lbs of a root ball.  I'm sure those were a big job to plant!  They must have made quite an impact once planted too.... 

I hope they do really well for you.

I'm no expert on all the different varieties of top dressing.... I just use horse manure here for everything. 

You'll need to keep the rootballs moist.  If you soil is more porous than the root ball, your irrigation can just run around the root ball.  You'll want the trickle irrigate right at the trunk to keep them alive until they can reach out into native soil.  Cross you fingers and say a few prayers--large nursery stock can have weird root problems.