I assume they were taken out their containers first. There is a trend in the industry to 'shallow' plant but that entails leaving only 2 in. of the soil ball above ground and mulching up to the top of the ball. During this is not a problem but if more than that was done, I too would have a problem. You should insist that they be planted as I outlined above, remember you are the PAYING customer. If they refuse call the BBB and any trade organization in your area.

The containers were removed, but the resulting soil/root mass was just set onto the ground. There was not even any breaking up of the underlying soil, let alone any part of the mass put underground.

Can your landscaper show you another and older planting where this method has worked? (Preferably older than two years.)

My concern would be around the 'wicking' away of root ball moisture if the mulch was moved by foraging birds.

Until you can either get visible evidence that the method works, or get your plants installed the way you expect - keep them damp. It can be difficult to re-wet those dense, fibrous rootballs if they dry out.

This is insane. How are you going to water plants with that deep barkmulch in the summer. The 4" plants will be way off ground level to bring them up to match gallon plants. These things can even be blown over, whats to hold them down (for a long time, anyway). How can the roots spread out. I know a few plants can be planted a couple of inches higher,but this is new to me.
Even if it was totally aged compost, it is lazy and a little weird, but bark mulch is crazy. What if you want to spread seeds later on, or add bulbs. Maybe the landscaper(?) is attempting to do a lasagna bed and got confused. I have never seen any planting instructions like this.
I am clipping this post would you please come back and let us know how things turned out. My gardener would love this method.

Anyone's would. I have never heard of such a bizarre thing, but if I were you, I'd go to the Landscaping forum here on Garden Web and ask them. A lot of Landscapers hang out there.

And a year's guarantee, so what? You're not going to know how your stuff is doing next March. They'll just be coming up.

I wouldn't question this quite as much, if they'd buried the plants in compost, but wood chips?? I would think it would be guaranteed all right---a guaranteed failure.

I think there must be more to this story than meets the eye :-) Planting high is very common with heavy clay soils as are common in much of the Seattle/PNW area, but "high" is one thing - out of the ground entirely is another. And when the plants are planted high due to soil conditions, it is also very common to berm or mound up a mulch (doesn't really matter which kind) to cover the exposed portion of the root ball.

It would have been much more preferrable to amend the soil sufficiently over the entire planting area to accomodate proper inground planting. If all is true to description, sounds like cut-rate landscapers taking dangerous shortcuts. And since I'm in the business myself, I feel very comfortable saying that :-) This is not SOP for any quality operation, although the high planting technique described above is an accepted practice for specific soil situations.

If the OP is still hanging around, can you post photos of the plantings? And what are the plants doing now, two months or so down the road?