see link on proper watering ....

https://sites.google.com/site/tnarboretum/Home/planting-a-tree-or-shrub

cant really give you much more specific info.. not knowing your soil ... but i am impressed your tree dude told you to CHECK ... bottom line.. you water when the plant/soil needs water .... its not really a calendar/schedule thing ...

at planting ... you should wet the entire rootball planted.. and out into native soil ... and not water again .. until to soil is near drying.. 3 to 6 inches down.. so you would need to dig a couple 3 to 6 inch holes ... in the ball planted.. and just into the native soil.. AND FIND OUT.. when this occurs ...

and in livonia and adrian.. in my decades of experience.. that might not be until july when the real heat of summer starts drying the soil at depth ...

of course.. you dont mention mulch.. and that would slow down the drying ...

do you have a warranty??? .. if so ... you might want to follow the sellers instructions.. somewhat ...

does your soil drain ... or are you in bad clay ...

finally .... you should check moisture deep into fall ... you dont really stop watering.. just because you put away the lawnmower in october ... nothing could be worse.. than a drought inn November.. and going into winter .. ground freeze ... low on internal moisture ...

ken

btw: these very large transplants will be stressed for 2 to 3 years ... and imo ... fert is NEVER a response to stress ...

So for the initial watering, he said 10 minutes on 4 sides of each tree.

They are mulched. Soil looks to be some clay. I will post some pictures.

The trees are wholesale, no warranty. They did offer warranty for 25% of tree price, but I passed - insurance is never a good deal.

Do you think 10 minutes on 2 sides of the tree with the hose is enough or is deeper watering recommended? I know what they recommended, but I like to have as much insight as possible.

What do you think of those $10 soil moisture meters from home depot?

I am watering pecans # 85, 86, & 87. Transplanted in February, about 5' tall, 1.5" caliper. I give them ~30 gallons a week if no significant rain falls during the week in Z8 Tx. if you want to compare. Your trees are about twice as tall, probably twice as thick, but you are in a cooler area. 10 min. of trickle water on each side - 40 min. altogether sounds like a good rule of thumb to start with.. Depends on how strong your "trickle" is. I would place hose on edge of root ball and try to give them ~ 50 gallons/watering. Then as others have said check soil for moisture during week and adjust accordingly. It is important to give them plenty of water during the first summer. Good luck.

Watering is never a simple answer. There are too many variables. Type of tree, time of year, weather, soil types, just knowing what words mean. Because the same words do not always mean the same thing to different people.

And in the last couple decades, if you use words like, check soil moisture, the response is kinda like...you mean touch the dirt? With my hands?

Rule of thumb: inch of water a week. From the sky, from a hose, whatever. How you accomplish that, is up to you and the resources you bring to the project.

On the surface, the instructions given seem to suffice. Simple, easy to follow. I'm sure there is a reason he gives the instructions he does. And you gotta check.

Re-read Ken's advice, including the article he linked. He gave you a very good answer. Ignore anyone why tries to give you a specific volume or time schedule unless they are very familiar with the soil and conditions in your yard. If they try to give such advice and aren't familiar with the specific conditions at the planting site (your yard), then they just plain don't know what they are talking about.

If the tree farm that you mentioned is local, MAYBE they are familiar with your conditions. As Ken said, it's good that they said to check. There are detailed instructions in Ken's link about how to check. Forget the $10 moisture meter. Your tree and your wallet will thank you.