I haven't planted in unfinished beds, but installing now doesn't sound ideal to me. You'd basically be planting in unfinished compost, compost that is going to break down and be reduced in volume, depth/height depending on how much material you've added. If you add soil to planting holes and your shrubs have something more stable under them, won't they be sitting higher than the rest of the bed level by Spring?

If you weren't fiddling with unnatural layering of different materials you could plant right away. Nature operates with a single layer of organic debris (called "mulch" in gardens) on top of a single layer of soil. No alternating layers of soil and debris etc. This is what plants are adapted to grow in.

What you have now is basically a compost pile spread out over the ground. Same as with a compost bin it's not really suitable for planting into. Producing the compost in a separate area designated for compost production (such as a bin) and then spreading the finished compost around plants would eliminate the situation you have now where the planting area is tied up by a composting process taking place on top of it.

Morz8, you're right, with the perennials this was an issue, but they seemed to "sink" with the compost for the most part, and anything left too exposed I topped up with finished compost as needed. I'm curious if anyone else has tried this with shrubs.

I think the answer is no, at least among the members of the American Rhododendron Society that I know. They use the best materials they can find, not some gimmicky experiment.

The bed must have excellent drainage.
The soil must be acidic.
The bed must have a good mulch.

Provide these things and you will have a good rhododendron and azalea bed.

The next concerns are exposure to sun and wind.

Winter sun and winter wind create stress on plants. Some tender plants will need protection.

Summer sun is also a problem to some plants. Too much sun can cause some varieties to have lace bug problems. Too much sun can also cause sun scald on some varieties. Too little sun can prevent some from forming flower buds.

When I plant rhododendrons and azaleas I just use composted peat mixed with the native soil with pine bark mulch over that ... no lasagne.

Never mind. I came for help from someone who actually uses this method, not snide comments from those who think it invalid.

This is the exact procedure that I do and have been doing. I do not know about cold areas of the country, but here in the Buffalo area it works great for me. The reason I started doing it was that I wanted to plant these critters in a basically basic soil situation, sweet, yes, but not good as we know. I wanted drainage. I wanted a high organic matter content, in fact, here is what kicked me into the beehive. From my reading and looking at research the comments were that the ideal growing substrate was LEAF MOLD. Last winter I used alternating layers of shredded office paper and coffee grounds. This year I have compost, leaves, light layer of manure, leaves, pine needles and then a top dressing of coffee grounds.
I got it about a foot to 18" tall.

To plant I cleared an area for each plant. Into that area I placed a soil mixture, tuned to acidic loves of rhodies. I am using small shrubs so this area might be a foot to two feet in diameter. Into that soil mix goes the plant.

Now I have a huge bed with, if you will, rhodo pimples here and there, along with some arborvitae. The soil mix is as high as the lasagna.

But the lasagna will decompose and shrink? Oh baby I hope so, cause that means it is going the way of the dodo bird. I will simply keep layering things on top. Can you say replenishing organic matter? During the spring this will be rough bark or other mulch. In the fall, there we go again with layers of leaves, etc.

Mangia mangia!

So paddykevin, you are planting rhodies in the acidic soil mix pimples, not the lasagne, is that right?

If so, my response that no one has tried growing rhododendrons in lasgne yet stands. That makes it an experimental situation.

My comments that if the lasagne provides good drainage, is acidic and is mulched, the rhodies should do OK still stands.

Lceh, I apologize if that sounds snide. You asked "I'm curious if anyone else has tried this with shrubs" and I said no. From your statements, you only tried it with perennials, not shurbs.

I think my answer still stands, which was no one here has tried it. I am sorry that sounds snide.