OK, I've been researching this further and I've given up on the idea of planting something at the top of the tree for the fact that it likely will not survive our winters. I'm now looking for a vine that I can plant in the ground next to the tree trunk, and send it up the trunk to reach the roof of the tree house and spread from there

Its been an interesting journey while researching these vines. Im looking for a fast grower that can reach a significant height, and Im not easily scared away by pruning & that type of maintenance - I enjoy it. This led me first to Trumpet Vine. It sounded like it could climb to the roof of the tree house in a season, and its not delicate or hard to grow. The flowers would look nice, but would also attract bees and insects that we don't really want... Then I started reading more of the posts about this vine and I had visions of this vine taking over the tree house, then the yard, my house, and also my neighbor's houses. I didn't want to bring this kind of destruction on my neighborhood so I started looking around for another vine. There are a lot of horror stories out there. One of the images that came to mind:

I then started looking for a fast & tall grower that didn't flower and bring the bees along with it. We already have hops growing in another part of the yard and love it for that area. However, for this tree house I am hoping to find a vine that will not die back to the ground each year, so it doesn't have to make the 16' climb each season before it can start to fill in the roof.

Next up was Virginia Creeper. Doesn't have the insect problem, fast grower, woody stalks stay through the winter, so far so good. It sounded like it also would try to take over the neighborhood, and has to be kept in check and requires pruning - OK, I like pruning, I can run a mower around the base of it, and I have a chainsaw in case it goes Jumanji on us. I've nearly made up my mind about going with the VC and planting and then I come across posts like this one about how poisonous/toxic/allergenic this plant can be! Other sites and forums & sites dont mention it at all... And I was getting ready to make this a significant part of a children's play structure!

So far this experience has made me realize how clueless I am in this selection - apparently I am attracted to all of the wrong types of plants. Any input would be appreciated. I am starting to wonder if rafters, sheathing and shingles wouldn't be a better route.

My latest search has me looking at Hardy Kiwi vine. I like the first word in it's name. Im not really looking to harvest any fruit from it or deal with that mess, but it might be interesting in the future to get a male pollinator and have some hardy kiwis. I read that it can reach 60' heights and can grow as much as 20' in a season, which sounds good. Does anybody have any experience with this vine? Does it sound like a potential fit?

How about an aggressive wine or eating grape? I'm sure there are some native to your area. I'd plant two, on opposite sides of the trunk. It's their nature to climb and the put out curls to aid them in that mission. Their canes will cover the roof and shade it. Leave the dormant thatch and in the spring it will break bud and you will have a nice canopy. You tube has lots of videos on pruning grapes, but basically they don't fruit on old wood. Prune each cane back to 4-5 buds. Each bud contains one cluster and one new cane. You can choose strong canes to bear and grow for next year and completely prune out others. I bet your son would enjoy sitting in his house and eating grapes. I can't speak to your kiwi question.

Thanks for the suggestion Suzi!

I was just about to post a question about this exact topic. We are building a fort for our son and want to grow vines as shade cover for him. I was inspired by this photo but have no idea what plant this is. Honeysuckle?

Our project has one wrinkle in it we're going to put a foot of pea gravel under the fort and I'm wondering if I can plant directly in it, or if I have to plant i pots (maybe with the bottoms cut out).

Our local nursery suggested wisteria, but I don't know that you'd want that on your tree.

whoops, it's here: https://s-media-cache-ak0.pinimg.com/736x/ae/40/8d/ae408d888c7c9442c1cdc12ef06751c5.jpg

bewareofzebra. All I know about wisteria is that it has killer invasive roots, so keep that in mind. You can buy planting sleeves which are tubes that protect the trunks of your vines. Google them. I would plant my vines first into the ground, use the planting sleeve on the trunk, then put that foot of pea gravel. You also need to figure out how you will water. All our plants, vineyard and fruit trees are on drip.

Thanks Suzi, currently the area is watered with a sprinkler because it's an old pond surrounded by flower beds. I think we can run a drip over to specific plants if that's what we need to do! So now our plan is to fill the pond with dirt after we cut the liner out, cover with landscape fabric, build the play structure, plant our vines, then fill with mulch or gravel. I'm not sure I'm worried about the roots since the area is pretty much an island in my yard...

BoZ: Good luck on your build. That is a cool photo you're using as inspiration. Wisteria was suggested to me also. Im not too concerned about a vine hurting the tree, it is dead and is basically a telephone pole now. I was turned off by the flowers and the bees that would come along with wisteria.

Thanks Jeff...honest in the tree is dead, go for virginia creeper! I have tons in my yard but it's much easier to manage than English ivy (which I HAD until I went crazy ripping it all out, ugh) . I don't mind the creeper and it's easy to train and prune.

See iif you can find a seed grown wisteria, they are notorious for taking up to 20 yr to flower. Then plant it in a pot at the bottom of the dead tree so you don't get it spreading. The pot should be at least 17x17 inches.