Aspen tree in backyard dying - what to do?

[AaronP]

Hi Folks,

I live in Highlands Ranch, CO (near Denver), elevation 5,600ft. We just purchased a house about 6 months ago that has a couple of Aspen trees in the backyard. I have been told that these types of trees are very hard to keep alive at our elevation (preferring higher elevations?) I have attached a pic of one of them. As you can see, the right trunk has some new leaves at the very top only, while the left trunk has no leaves at all. I pruned all of my trees last fall (my first time pruning, so I can't guarantee I did a good job). One of my aspens is thriving nicely, but the one in the pic seems to be more-than-half dead. What should I do? Should I chop down the left trunk so the right trunk can possibly still live? Chop down the whole tree? Any help will be greatly appreciated.

Thanks,
Aaron

View attachment 235854

 

[Kottonwood]

Interesting, I usually see them dying from the top down due to root rot. Either way it seems that tree is on it's way out. Aspens are not really a long lived landscape tree. In optimal natural conditions they can make it up to around fifty years, in a landscape they rarely make it past twenty. I am guessing 12-14 years old on yours. The most likely cause is overwatering. It seems you have a nice green lawn right next to it. Your best bet to keep the aspens healthy is to mulch around them and keep the irrigation away. Aspens are native to Colorado and are genetically designed to live in our arid climate.

Your best bet at this point is to cut it out. Aspens will sucker back from roots and the stump though. If you want to save it don't grind the stump and let a sucker come up that you can train into a tree (make sure not to kill it with your lawnmower). Aspens are pretty fast growing so you will have something decent there quickly enough. Also you could just grind the stump and plant a new aspen clump, they are cheap to get around here.

 

[pdqdl]

You might check for borer holes.

The dead stem appears to have had some lawnmower injury in the past. This can weaken the tree. Borers move in, and that stem dies off.

The other side might be infested, with a sure decline coming, or there might be nothing wrong with it.

Time will tell. It doesn't look like you need to be in a hurry to cut it down.

 

[pdqdl]

Are you in some sort of drought condition there?

The tree in the background (maple?) looks like it is have some sort of major problem in the crown. Lots of brown/yellow leaves.

 

[Kottonwood]

Are you in some sort of drought condition there?

The tree in the background (maple?) looks like it is have some sort of major problem in the crown. Lots of brown/yellow leaves.

It is more or less drought condition. That maple also most likely has an iron deficiency. The soils here are generally pretty alkaline and the maples have trouble getting iron out of the soil (even though if you do a soil test there is plenty of iron). Quick fix is an liquid fert injection with an iron concentrate. I will be honest I don't see that aspen making it another year or two. Once they decide to go they go.

 

[Kottonwood]

You might check for borer holes.

The dead stem appears to have had some lawnmower injury in the past. This can weaken the tree. Borers move in, and that stem dies off.

The other side might be infested, with a sure decline coming, or there might be nothing wrong with it.

Time will tell. It doesn't look like you need to be in a hurry to cut it down.

I very rarely see borers in Aspen. Most common problems are overwatering, leafspot, and aphids.

 

[pdqdl]

There sure is a lot to be said for knowing the local conditions, isn't there?

No borers up there for the aspen? I'll bet that is related to the harsh cold winters. Do you have woodpeckers up there? If borers are not prevalent, I would expect to see fewer woodpeckers.

We have armies of them down here. Borers, and woodpeckers!

 

[pdqdl]

I see lots of iron chlorosis around here, but invariably due to the high limestone content. KC only has limestone rock in the area, so it is pretty common.

I always thought the rocky granite soils up in the mountains was inclined to be acidic. I stand corrected.

By the way: Iron sulfate soil injections do a very good job treating the soil on a permanent basis. You need to make a LOT of injections before it works, though. I refuse to do temporary fixes like liquid iron treatments, unless coupled with a long term solution. I figure that I am just taking the customers money without providing a lasting benefit.

 

[Kottonwood]

That makes sense, iron sulfate to add iron and increase acidity. I am just really getting into the PHC game and I am with you. Most companies out here offer the quick temporary fixes and have you sign a multiyear contract. I am not into that, I am always looking at the long term solutions. The thing about CO is that it is just plain hard to get good trees to grow here. If you want nice trees on your property get real friendly with your local arborist (preferably certified arborist) and stay away from companies that want you to sign a multiyear contract. Those companies will keep your trees nice and healthy but it will cost an arm and a leg.

As far as soils go out here on the frontrange it is mostly very clay based with very low organic content, hence the tendency toward alkaline. When you get right up to the mountains the soils will be more acidic. The other issue with the clay is the horrible drainage, not good for the aspens they like a lot of drainage.

We have plenty of boring insects out here, they mostly attack ash, pine, locust, and some others. Aspens seem to do ok though, the bottom line with aspens are they are just not going to live a long time on a landscape. They are meant to be in a grove where they can continuously regenerate through root suckers, the suburban landscape is simply just to different from their natural setting.

 

[Kottonwood]

oh, another thing we do a lot of to combat the soil disadvantages we have is vertical mulching. I started doing it a couple years ago when I started my business because it did not require much extra equipment (just an auger). So far we have had very good luck with it.

 

[Kottonwood]

There sure is a lot to be said for knowing the local conditions, isn't there?

Yep, you said it.

 

[sgreanbeans]

We did the vertical mulching in SD, worked really well.
Not to hi-jack, Sorry OP
U guys talking bout the PHC game makes me jealous, really wish I could get a client that was interested. They are so used to "shoot from the hip" diagnoses, that's all they want. I remove lots of trees that are treated for the wrong thing and in turn, killed, by the same guy trying to save it. On the other side of that, I have saved several trees from removal, as they where given a BS death sentence. Looking forward to being able to do long term PHC programs in SoCal. I cant even get real lab work done here. You would think, beings I am only a couple hours form the biggest plant lab in the world (Iowa State) that it would be common, nope, all ag, which I get, but the extension's should be able to send in samples for anything, they will do PH levels, but that's it, no disease action. Really want to get one of those field soil kits and start doing it myself. Almost ordered one a while back, then at the last minute held off, thinking that when I do get to SoCal, I wont use it............but I still want it!
Another side note, can someone tell me why I see woodpeckers beat on gutters all the time? Its nuts and SUPER LOUD!

 

[AaronP]

Thanks so much for the replies! Okay so I should chop the tree down. I'm thinking I might have the stump ground and leave it at that, or maybe grow something a little hardier. Any suggestions on tree types that will last in a suburban setting in this area?

I'll mulch around the other Aspen to hopefully keep it live; good advice. I have other trees as well but don't know the species. Are there other types of trees besides Aspens that I should mulch around?

The maple tree is my neighbor's and I also mentioned to him that it looked like it was on its way out. I gave him your advice and he was very grateful!

Lastly, can anyone recommend a good Arborist in the Denver area to help both me and my neighbor?

Thanks!
Aaron