I forget: is this from the Niobrara provenance or named 'Prairie Gold' variety that can take lower altitudes? If not, the plant doesn't like to be that low in altitude and is suffering; maybe they will eventually adapt if they have sufficient water.

Aspen are a crapshoot at lower altitudes.

Dan

Something I've heard about aspens in lower alts is they get something I've heard at the local nurseries as, "the fungus". This supposedly prevents a lot of the aspens from turning. I've heard the altitude argument, but I've also heard aspens will turn if healthy.

I discovered an insect drench that is a systemic insecticide, I'm also going to look for a systemic fungicide that doesn't have to be sprayed on and that I can water in.

Thanks, Dan and Bob. I'm looking at aspens on our block which are turning gold, so I don't think the altitude is the problem. I can't see any fungus either. Any other ideas? And thanks again.

Susan

Altitude alone is probably a red herring ..... as Actually aspen occur naturally at sea level and the range covers a tremendous variety of climatic zones and ecosystems in North America and although sourceing plant stock from wildly out of range might cause problems....they would most likely express this immediatly and terminally over course of first year or so in the ground....some aspen are poorly harvested particularily wild dug....be very suspisicious of tiny loose root balls in net sacks almost always wild dug (seed grown with healthy root development always a plus)...with low transplant success....
Aspen are highly susceptible to a wide range of pathogens and pests many of which stress rather than kill immediatly,,,anthracnose in aspen sometimes can result in your symptoms as can leaf miners et al....fungus and mildew would be pretty obvious with evidence on bark ...sooty accumulation...heat and or moisture stress can result in similar appearance..... soak them in at end of active growing season if possible... and although not a fan of fertilizing most established trees esp populus..... I have however seen very posative results from treating with mychorhiza...might be worth it next spring.....

as Actually aspen occur naturally at sea level and the range covers a tremendous variety of climatic zones and ecosystems in North America and although sourceing plant stock from wildly out of range might cause problems...

I agree, as I have seen them at ~sea level in WA (many more in mountains, tho). Around here they don't grow well at these altitudes - maybe 2-3 in 10 look good for a few years then decline.

Surely they want a particular set of climatic conditions and hereabouts such conditions are generally expressed in altitude, as stated in the Front Range Tree Recommendation List: "Better at high elevations, chlorosis at lower elevations, prone to many diseases & insects".

As it is one of my favorite trees, I'd like one (then 5, then 10) in my yard. Alas, no such luck. More disappointment than joy with that one; that doesn't stop folks from trying.

Dan

I was working on a project in Rhode Island a couple years back and feeling pretty distant from these Montana mountains...., and throughly enjoying my walk through a coastal new england beech forest just beginning to turn,when I heard the unmistakable crackling of aspen in a breeze and amongst the beech a stand of bright yellow aspen within 5 miles of the atlantic.....made my day
I think you are right Dan that it is often lovingly planted in marginal habitats...and therefore the importance of sourcing becomes more important for estab/ longevity of stand... Lawyers grows from seed...might be worth a check for you (wholesale too)
Having said the positives ....I do however think its suitableness for large scale urban plantings(public or private) both within its prefered range and beyond has room for discussion....while certain aspen colonies have been proposed as both among the oldest and largest living things on the planet... in a domestic environment they often simply are another poplar with all that is associated with that genus ( although i do have a real weakness for the silver poplar...talk about a tree most homeowners should stay well away from).... and can be far from trouble free to establish....have any of you folks tried
Populus tremula...

Thank you, everyone. We have five of them in a little grove and all look about the same. I cannot see any evidence of insects or fungus. mtny, I'll make sure they get enough water and try the mychorhiza in the spring. In the meantime, I'm enjoying the gold on the mountainsides near us.

I'll ... try the mychorhiza in the spring.

No guarantee, susanka, that a consumer product will have the one(s) you want. A trowel of soil from underneath a healthy stand is all you need. Sunday we're driving thru the Kenosha-11 Mile-Rampart ranges to look at aspens (and bighorn sheep). Fall in Colo: superb!

:o)

Dan