FYI 30 ft. is a small tree, as far as it goes - linden or otherwise. For instance I've seen a linden tree over 100 ft. tall. And there are coast redwoods still in existence that are more than triple that height.

Ask local tree services if they offer anything that would help with the aphids.

Thanks for replying, Embothrium. I suppose what I meant is that the tree is too tall to use some of the suggestions I have read, like blasting the aphids off with a high-pressure stream of water, or spraying with dormant oils or insecticidal soap. I could probably reach the lower branches of the tree easily enough, but even with a ladder I can't do the whole thing.

I did contact a few tree service companies in my area, and they're quoting me $250-$300 per treatment (spray), with about 2-3 treatments required per year. Even then, they say that there's no guarantee the aphids will stay away - if there are neighbouring infestations they could make it back to my tree. My guess is that they use similar methods (oils & soaps) but just have the equipment to be able to do the entire length of the tree.

Sigh...I'd rather not have to spend $500+ each year trying to keep these pesky things away. I think I would rather consider having the tree removed and planting a smaller tree, one that maybe isn't as prone to aphids. But that will be a last resort.

If anyone else has succeeded in organically treating a larger tree infested with aphids, please let me know!

There won't be any organic method that doesn't involve spraying the whole tree. And it's just going to get bigger and bigger.

Interesting that there would be a lot of aphids on your Linden at this time of year...there shouldn't be any succulent new growth that aphids love/need. I'd see what happens next year before doing something really drastic. Also, aphids aren't really species specific so you could just as easily get an 'infestation' on a replacement tree.

New Homeowner, you & I have something in common, we both have a 30+ft linden tree which we park under. Honeydew is a problem especially on the windshield. Sometimes I make a point to park under my pecan tree and that can be messy also. The honeydew problem only lasts for a couple of weeks, I clean it off when I fill up. I definitely do not spray with anything. I consider the benefits of the linden outweigh the problem.

Aphids are very attracted to lindens......birches experience a similar attraction. The damage they do a tree of that size is negligible and it isn't worth treating for AFA the tree is concerned. It is more the nuisance value that they create by raining down the honeydew :-) The easiest option is just to remove the tree (and replace with something less inclined to attract the aphids, if you feel the need). Otherwise, you pretty much need to just put up with it for the rest of the season, as the leaves will be dropping before any control/treatment you apply now will have time to work. Early spring would be the time to use a systemic.

Just an FYI, but there are many very plant-specific species of aphids........linden aphids, Eucallipterus tiliae, being just one (there are also numerous species of aphids - different from the linden aphids - that focus almost entirely on birches). Hellebores and lupines also have their own, personal aphid species :-)

My point was that one is likely to experience aphids on the next broafleaf tree at some point, regardless of the species of tree or species of aphid.

where are you ... that you would be thinking of treating a deciduous tree in mid September ... for about half of us ... leaves will be falling in a month or so ... and it would not really be high on the cost/benefit ratio.. to bother treating ... and cold night temps meanwhile ... will take care of them ...

some trees just have to go .. period ... and if.. as you say.. its driving you crazy...well.. just get rid of it ... period ... one might suggest.. your mental health is of higher value than some random carp tree ... [carp in the sense of driving you crazy] ....

this is another situation of a prior owner leaving the new owner a nightmare .. and the new owner hesitating on removing the problem ... if they had left you a paisley kitchen counter.. ala 1970s ... would you hesitate to get rid of that nightmare??? .. just do it ..

ken

wait.. it was the paisley wallpaper .. change search to avacado ... if you dont like the harvest gold.. lol ... or maybe it was the shag carpeting...

https://duckduckgo.com/?q=1970s+kitchen&t=ffcm&iax=1&ia=images

https://duckduckgo.com/?q=1970s+shag+carpeting&t=ffcm&iar=images&iax=1&ia=images

And if you just can't get rid of the tree, you could try one of these. (not real serious about this one but it is another option).

In my region Norway maples are also excessively prone. Otherwise it is not usual to see deciduous trees producing copious aphid drip here. There are even particular species of lindens that can be planted, without an expectation of bothersome aphid infestations being involved.

New Homeowner: This is a couple of years late, but we had the same problem on our street in Oregon. We used small hanging vials of a tiny bug called the aphid midge, aphidoletes aphidyzma. They're raised by a company in British Columbia, and we got ours from a distributor in Clackamas, Oregon. We deployed them along our entire street in 2018, and they did the job. In 2017 we were covered in aphid dew, and last year we had none.

BTW, NH, I've asked the owner of the company in Clackamas, and he will sell all amount. You can buy only one vial of midges, but the shipping cost is the same.