I'm not sure exactly what part you're saying is mythical. From what you've posted: "Coarse Sand or Gravel Subsoil Fine soil overlaying coarse sand or gravel subsoil must become very wet before water will move down through the large pours of the subsoil. Under these conditions, the overlying soil holds up to two or three times as much water as it would if the course subsoil were not present" And that's exactly what I was talking about. The water "perches". It's not actually 100% saturated but it is water that is perched until you apply enough for gravity to suck it down into the subsoil. With proper irrigation management, you can perch the water where you want it and use that effect to your advantage. Of course, that saturated zone (not actually 100% saturation but close enough for the girl's I go with, as my grandfather use to say) Will be bigger in a fine soil over gravel due to greater capillary action but it will still be there in a sand over gravel. You might have a 5 or 6 inch layer of saturation in a heavy soil over gravel and a 1 or 2 inch layer in a sand over gravel. In the paragraph above that, your reference states (when placing a find soil over sand): "When water passes through a fine layer and reaches a layer of coarse sand, it stops until enough water accumulates to nearly saturate the fine soil" Note the use of the word "stops". Again, this happens when going from a sand to a gravel due to a difference in capillary action of the two different layers. Again, this is the effect that we use to "perch" water where we want to so the roots can get to it. As far as a clay layer goes, you're right. You can perch water that way too. "Clay Layer When water reaches the clay, the very fine pores of this layer resist water flow. Although water does pass through the clay, it's penetration is so slow that water tables often build up above the clay." In that condition, note that water actually moves but slowly rather than coming to a dead stop like it does when you put a finer material over a coarser material as discussed previously. However, your zone of saturation will be larger and you can't "push" water into the subsoil when you need to by applying a bigger head of water. It will just perc as slow as the clay will allow it to move and no faster. It's harder to control soil moisture that way. Both of these conditions become less and less important the deeper in the profile the textural interface is but when the interface exists relatively near the surface, either by accident or design, it can be an advantage or a liability depending on intent and management practices. ("Or so the legends of yore go.", I suppose I should say)

Thanks Val. The pipe pot design is all my own. I got the idea for them when I was inspired to give zinnia hybridizing a try on the annuals forum. I needed a container large enough to grow zinnias to first bloom. Zinnias don't like to be transplanted, so I needed something with almost zero root disturbance. The large volume of potting mix needed looked cost prohibited unless I could use my loose garden soil and get it planted without the soil falling apart and damaging the roots. I explained what I would try back in January ... (for Otis, the planting tool is shown) "Pipe Pots" Back to the subject of clay ... As was noted by others in this thread, best science says not to amend clay when planting trees and shrubs. The same can be said for perennials. Because the organics decompose, are used up, and the soil returns to the original clay. One can grow annuals in clay by amending with huge quantities of compost added each year. But once you tire of fighting the good fight, the soil returns to clay. What happens if you amend with sand? I said I had an example of long term effects of sand amendment, and now that the sun has come out I have photos and video. The photo below was made back around 1994. The pinks and snaps are spilling from a bed filled with a sand/clay mix made from the same type clay shown in my first post. The bed was in an area that would be destroyed in a grading change and I abandoned gardening there in 1995. Since then the only activity there has been a once a year cut back of all weeds and growth from the bed. No organics were ever added to this bed and for over 10 years it has not been disturbed, dug, fertilized, or watered. The new retaining walls are now being built and the new grading done. There is a small part of the original bed still remaining with the bed wall removed. In the photo below I have outlined the spot where the snaps and pinks were growing. Please note the dark color of the soil is nothing like the look of a fresh sand/clay mix as I have shown in earlier posts. It is the natural buildup of humus in a fertile soil complex. One might begin to wonder if high humus soil is merely an indicator of fertility rather than a cause of fertility. I repeat, no compost was ever added to this soil. I took a sample of the soil, shown below. Click the photo for a short video. The video shows that after more than 10 years of compaction, the soil can still be dug with a hand spade. The sample was taken after several rainy days and is very wet, but it's not mud and could be dug and worked. Note there is none of the normal soil peds of a good topsoil, but the permanent texture of a sand clay mix is obvious. Many small clay lumps persist in the mix and I mashed one to a small disk in the foreground of the photo. I seldom find a worm in my sand/clay beds. Worms are not necessary for fertility in all soils. For soils that contain greater than 50% clay, the books are all wrong to say don't amend with sand.

I found pictures from the fall of 2016, I think these (red pine) were planted in the spring of 2015 (possibly fall of 2014) and I had one die by spring of 2016 so replaced it with the larger one on the right of the picture. I just thought that if I planted one the same size, the other, more established ones would overtake and outgrow it. I was right, they are almost the same size today. There is one White and one Jeffrii(? still haven't seen cones) toward the left side, away. The half dozen on the right side are a year older bc I added some on the left a year or two later. They're all getting established and growing so can't complain and I didn't water any of them this year, they were all free range and did well. I've always thought pines are a little like cactus being they grow in the sand and endure dry spells quite well once established. These are all originally intended to be a windbreak/screen from the neighbors yard, along the alley (where I stood to take picture). This area was part of a farm field maybe 35 years ago. Sand underneath and silty sandy loam. My backyard is actually a rise where the topsoil thins out to 6" in the middle of the yard and is more gravelly. The better soil is more near the house and out past where I'm taking pictures. The good part is, we never get water in the basement. We are a 'high spot' in this town. All sewers drain down hill away and we have a basement floor drain. I have one of the larger back yards in this neighborhood. So who knows what I'll come up with next. :-)

Yes: pull your tree up immediately and plant it where it does not sit in a puddle, hope that it bounces back. Due to root death drowning plants have the same problem with not enough water getting to their tops as those where there isn't enough moisture in the soil. If you have nowhere there that isn't a damp and heavy soil that puddles when water is abundant then you will probably have to make a berm or mound of purchased soil for this tree. Or give up on trying to grow drainage sensitive kinds like this on your site. The only other option is to install a network of pipes that collect the excess water and move it away. To be able to do this you have to have access to a low area for the unwanted water to be directed into. Basically a retention pond, depending on how much water may be involved.