Only if I'm taking a chance on providing an environment not suitable to its cultural preferences.

I can't get a rhodie or chinese dogwood to grow in glacial till in my zone for the life of me.

As an ignorant gardener, this happens to me all the time. It happens when I plant a native not commonly planted in suburbia in my area. I planted some Pitch pine and American Holly...no idea what they will look like growing in a lawn with minimal competition. I mostly see them in the woods.

I also purchased a couple scarlet oak/willow oak hybrids. Willow oak isn't commonly grown around here because it is borderline hardy...and I don't know which parent the hybrids will favor. I'm hoping I'll end up with red fall foliage that is shed completely and cold tolerance...but who knows?

(whaas_5: Oddly, my parents have a HUGE rhododendron growing in glacial till. They have a Chinese dogwood but it looks sad.)

FWIW, glacial till is the standard soil condition for most of the PNW and both rhodies and Chinese/Korean dogwoods (really, dogwoods of any kind) thrive in this area. I would suspect it may not be so much a soil concern as it is something else limiting their ability to thrive.

Both whaas and myself live in eastern Wisconsin, although I think we're about 100 miles from each other. But regardless, the entire eastern portion of this state has neutral to slightly above-neutral soil pH due to underlying limestone bedrock. I'm guessing here a little bit-it's not as if I actually have his soil profile at hand here-but we too struggle with rhodies and it's down to soil pH. And then there will be the one that looks just great, growing where you know it's all full of lime and just not making sense. My son has one such rhodie-terrible location right next to large limestone patio, no special care of any kind.....and it blooms like crazy each year and has healthy dark green foliage. But generally, I thin k it down to soil pH for those of us here in the eastern counties of Wisconsin.

I have glacial till as well, but it's mostly granite so it has low PH and rhododendron should grow well here. My largest problem is low fertility, probably lack of nitrogen. Some trees, like celtis occidentalis, just hate it, I tried twice and there was no way. Maples grow only in better parts of my land and much of it I have to fill with oaks, beech, alder and other low-demanding, acid-loving trees.

huggorm: Oh no! You can't grow Norway Maple you have to fill your land with beech! <jealous>

Toronado3800 Zone 6 St Louis: So you would reccomend Metasequoia "ogon" as a trouble-free tree?

edlincoln: (6A) Oh no! You can't grow Norway Maple you have to fill your land with beech! <jealous>

Lol, I can see how that look for an american but european beech can grow in all kind of soils. It is much less demanding than Norway maple or any maple I have tried

The problem with beech isn't that it is picky about soil. (Although I hadn't thought of it as being super tolerant either) but it doesn't transplant well...it may spring up, but if it doesn't, it is hard to get it established. Around here it is more a tree you find in older forests and the yards of old estates then something that springs up in newly cleared fields or something you think to plant in a spot you can't get anything else to grow...
The trees that tend to spring up in abandoned fields around ear are red cedar, white pine, Norway Maple, Black Cherry, maybe oak. The trees people plant if nothing else will grow tend to be honeylocust, ginkgo, Austrian Pine, maybe pin oak or sycamore.

Could the problem whaas_5a is having with rhododendrons simply be zone 5 cold? Not many broad leaved evergreens do well in Zone 5...

Sorry to hijack the rather interesting thread.

No, it's pH. My soil pH is also a bit above neutral, and it is shocking how much of an effect it can have on certain plants. So much so that I am always on the lookout for plants that might work the other way - the dryland plants that really aren't objecting to the comparative lack of drainage so much as the too low pH.

To sort of get back on topic, last fall I bought a yellow buckeye which nobody seemed to know much about. It is on an island in the swamp, and can get as large as it likes, and is free to find as much water as it likes. Hopefully, it will survive my slapdash planting, and outgrow the reeds fairly quickly.

For some reason I just assumed glacial till was alkaline. Its a combination of ph and root type in my own personal experience. Anything that has fibrous roots and prefers an acid soil just won't grow. I literally pulled multiple hardy cultivars right out of the ground after they struggled for several seasons. They just wouldn't put roots out into the native soil.

H. quercifolia, Nyssa and Parrotia won't grow for me either! I do see them growing here and there in clay soils around me though.

I'm going to try Cornus officinalis this year to see how it does. Red Sentinel is a cultivar that supposedly has red fall color.

when I used to live in the twin cities, the common lingo used by designers and la types was that they carefully selected plants for your personal landscape based on soil preferences and adability to the area, ie, cold hardiness.

And if course you can rhoddies in high pH, clay soil, in a wind tunnel.

Ok, so the wind tunnels weren't that common, but my experience tells me that broad regions of the upper Midwest tend to the alkaline, and soils can vary widely over even small distances.

When I lived in mn, I was constantly trying things I had no idea of how they'd grow. if you rely on only the known reliables in that weather, your idea of exotic is how many varieties of spire and nine bark can you grow?

So i'd try different things. Korean arb? dead as toast before thanksgiving. Japanese Stone pine? still thriving without ever so much as the slightest winter burn almost 20 years later. Turkish filbert? one survived and thrives, one died after a couple years.

You try those things that you dare. the risk is failure, the reward is something no one else has. of course, as you move into milder winters, what is defined as questionable becomes quite a bit different.

Glacial till is just glacial sediment - its pH will be dependent on the type of rock that was eroded by the glacial movement centuries ago. If primarily a limestone or other alkaline rock, the resultant soil will be alkaline - if from granite or another acidic rock, it will be acidic. The mineral component of a soil is the primary contributing factor to a soil's pH.