Those might be a top-grafted Catalpa bingnoniodes 'nana' so they naturally grow that way.

However, you might be able to achieve the same look by pollarding a regular catalpa.

Here is a link that might be useful: Pollarding

ginkgonut is exactly right about it being a grafted tree. They are fairly common here in Utah and go by the common name Umbrella Catalpa.

Do not try to severely prune a "normal" catalpa or pollard it to get this look. It would simply result in massive growth the next year which would not look much like the pictures you posted.

Even with the graft there is still some pruning required to maintain the size and shape.

If you are trying for a whimsical garden for your kids have you considered a weeping mulberry? They can be trained to create a "room" for the kids to play in, and as a bonus the kids may like the berries.

Here is a link that might be useful: Grow an edible playhouse from a Weeping Mulberry tree!

Thanks for the replies. Darn, I was hoping I could just pollard a regular catalpa, but I can see now that won't work.

The weeping mulberry tree is a great idea. I planted a weeping crabapple with the same hope, to get a little "cave" inside. Perhaps I'll try a mulberry as well, hopefully I can find one locally.

THanks!

I've seen a lot of catalpas that look like Dr. Seuss trees without even trying (no pruning). Our neighbors have one that is recently planted that only leafed out at the tips last year and it *really* looked like a Dr. Seuss tree with its tufts of big leaves at the end of every branch. I think they'd still look cute in your play area without any pruning.