I would also want it to compete with the Norway maple to slow its growth

===>>> yeah ... good luck with that ... lol ... if the most invasive weed on earth ..... grass ... wont grow under a norway.. good luck with anything else ...

if we are to presume that a tree is twice as large underground.. as above... how are a couple little vines going to slow it down ...

regardless ... give it a try ... if you can provide enough water for the vine.. in excess of what the tree will steal ... and the vine actually can become established and thrive.. it might be a really cool affect ...

i would recommend not amending the soil .... and never watering the vine alone.. bare rooting it.. and planting in only in the soil removed in digging the hole ... you might get it going..

but any amendment .. fertilizer.. or water specific.. will encourage the maple to come fill the hole you dug with feeder roots.. and in the long run.. strangle the plant .... i know this for a fact from growing some odd 1500 hosta under a myriad of trees ...

maples .. among others ... are super competitors .... and .. given time.. will take everything that other plants might need ... and norway is their king ...

good luck

ken

ps: even if you decided to increase your odds by trying to grow the vine in a 20 gallon pot.. under the tree.. on top of the native soil .... within a few years.. the roots of the tree will fill the pot.. these darn things arent even limited to mother earth .... maybe they are aliens ...

I have heard the trumpet vine is also very invasive despite it being native and I have read stories of it killing what it grows on (in this case I wouldn't mind that). Is it not aggressive enough to compete with my dreaded Norway. I forgot to mention in my first post that I plan on girdling the trees before planting the vine. I think that would take care of the root competition. The trees are on the back edge of my yard so there is more sun there which makes the spot for my vine semi shaded semi sunny. I don't want the vine to start becoming invasive and growing up my other good trees. That is one the of the main reasons for me being hesitant on planting this vine. I do think it has major upsides though.

Having lived in Maryland, I fought a losing battle with my neighbor's trumpet vine... it travels underground at alarming speed coming up all over in my back lawn, under and into my window wells, under my siding, growing faster than I could hack it down. Moving back to Minnesota solved the problem for me.

I'd think long and hard before introducing Campsis Radicans into my landscape lovely as it might be - with kudzu, ivy, Norway Maples you've got headache enough. But, if other's experience isn't a good teacher - plant yourself one and stand back. The foliage will do remarkably well in semi-shady conditions, but sun is required for the kind of bloom you're probably looking for.

In residential settings I am generally against vines on trees. The vine will help hide structural defects. If both trees can fall and not hurt anything you care about then go for it if you are 100% certain you can control the vine

yeah.. leaving out the fact that you were going to kill the trees first.. might.. JUST MIGHT ... make a difference.. lol

ken

Just because it's native, doesn't mean it's good news for trees. If you're trying to cause the decline of the norways (that isn't enitrely clear) then that's one way to go about it. But if not I think you ought to keep that stuff far away from the trees.

I would definatly kill the tree first. All you have to do is girdle it. Hack off as much bark as you can around the tree and wait for it to die. Once dead, go ahead and plant the trumpet creeper. The excess sunlight will increase bloom productivity. If you are worried about seedlings from the vine then you could get a hybrid like 'Madam Galan' which is suppose to be sterile. They bloom like crazy and the hummingbirds flock to them.

Thanks all! I have decided not to plant the vine for now. The trees are girdled though.

TJ

In 2007 I had a tree company remove 3 large Norway maples, as well as girdle a 4th. It took about 1 year, 3 months for the girdled tree to completely die. Once it died there was an explosion of growth underneath the tree, hundreds of Pokeweeds that sprouted from seeds dropped by the birds over many years, but were suppressed by the dense shade and allelopathic roots of the Norway.

Most of the bark has fallen off in the past year, in large chunks. The tree is now a hulking dead structure. It's kind of ugly, and will probably start dropping branches soon, but I must say, the birds LOVE this dead tree. It is a popular hang out and look out, especially in the summer. Trying to decide if I should have more of it removed and leave only a nice dead trunk for the birds.

You will probably be able to grow something under your Norways pretty well once they die back. Up here in zone 5/6, Trumpet Vine which is a north American native, wouldn't be aggressive enough to be a problem, but possibly it's too aggressive in your zone and will spread to the adjacent trees?

i did exactly what green thumbz suggested years ago, at my first house. I girdled a silver maple, planted trumpet vines, and it was a haven for hummingbirds and an occasional pileated woodpecker for years.

The maple was too close to the house and had gotten damaged in a freak october snowstorm. i just cut of limbs to the main trunk, and girdled the base. The stub with vines eventually fell over, but it was interesting watching the changes.