Clay is not the problem, poor drainage is. I agree with your local expert, I would dig them,when dormant, and plant them on a raised berm 12 to 18 inches high made of your native soil. I would not bother trying to change the soil texture with additives. Keep your soil mulched with about 3 to 4 inches of vegetative mulch at all times, only holding it off the tree trunks for an inch or so. This will help a lot in preventing compaction, which can be a problem with heavy soil. Al

I had the same problem with water logged fruit trees in clay. Al is right about raising them up but, you may find a solution in improving drainage, more easily.

After I lost an apple in a bog of water, I used a post hole digger and created a couple of drainage holes both uphill and the lower side, about 18" away from my tree.. I dug them about 4' deep and filled them with crushed gravel. That seemed to offer enough run away drainage! I get about 1550 ml, or about 5' of rain a year, here on Vancouver Island. Even with rad clay, I can grow Peachs,Plums and most of the seed fruit.
This may work and would be a lot simpler than re-planting.
Dunc

Thanks for your comments! The trees are just coming out of dormancy so I am reluctant to dig them up. Maybe I will try the drainage hole solution. I do not get nearly the rain you do on Vancouver Island (only 12-15" per year), but it would only take one huge rainfall to drown my trees.

If they are just coming out of dormancy they've spent very little energy and roots are just beginning to grow. You can safely move them NOW!

That drainage technique can't be what saved Dunca's trees IMO. They couldn't adequately pull water away, according to anything I've read on the issue.

You need at least a French or curtain drain that pulls the water down hill to create affective drainage- there's a reason that the simplest method is consistently determined to be raised beds by anyone who spends their lives playing in soil.

You may or may not benefit with some kind of amending but if you try to improve your soil best to stick with the top 4-6 inches by blending your native soil with black humus-like compost. You need to do this in a fairly wide area- at least a 5' diameter circle for each tree. If it's a raised bed, the entire bed's top 4-6" should be treated.

This is not the same as pouring amendments down a planting hole and requires at least a quarter cubic yard of compost per tree to get any results. Remember to keep the improved soil on top and spread some of your trees roots in it as well as the pure clay beneath when you transplant. Mulch when done with 3-4" of arborist wood chips (for free).

The idea that you can't improve clay with amendments is a confusion of research in my opinion. Adding some compost on top only speeds the process that is started by adding mulch anyway- the question is, is it worth the effort. Clay doesn't mix easy. It is worth the effort if the trees will otherwise languish- it all depends on the nature of your clay and how other trees are growing in it.

The research saying amendments are futile is about dumping compost in the planting hole- at least the research I'm aware of.

Dry wells have been used for many years, but dunca, your dry wells are small.
French drains & dry wells together are your best bet.
You can use plastic 55gallon drums as dry wells to hold the water from the French drains, if there is not an open ditch to dump the run off in.
You can amend your soil with sand, but it will take 50-75% sand to do it. That is a lot of digging.
As for Organic matter(compost) that is good no matter what soil you have or what type of gardener you are.
You can add compost every year also, your grass clippings & leaves. My Grandfather, father & I have used waste plant material to improve our gardens for over 100 years. This is not new or rocket science.

The problem with dry wells is once they fill up the drainage issue returns. If there is a general drainage problem in the area water has to be removed. What I've read is that when there is not the capacity to move water downhill one must use a pump to push water to where it can go down hill.

I've never so much as created a curtain drain and always plant trees on mounds when drainage is an issue so I'm not speaking from experience here.

It occured to me after my first post that Dunca's holes may have worked because he penetrated a hardpan or plowpan, allowing the water to drain through a hard layer.

Based on all the comments I think we will try to raise up one of our trees to see how that will work. What should I use as a fill under the tree to raise it up? Gravel? Good soil? Clay? A Mixture?
Thanks!

Harvestman, I have been reading your inserts and comments for a couple of years, and I do bow to your superior knowledge and experience. I was only offering my opinion and their results, your method is likely superior in the long run but, with less work.

dunca, I make plenty of mistakes, including suggestions on this forum and have learned an awful lot from people with lesser experience. Experience can sometimes enforce mistaken assumptions but I try to be one of the editors here and I appreciate your forgiveness for my presumption in assuming that role.

I have the same problem, planting at ground level in clay. I think I'll try a variation and use my tractor to rough out some drainage ditches then let the rain finish the job.
Dan