Face set with determination, Jon Vandervelde concentrated on updating his treehouse, while children scrambled up the spiral lattice surrounding the tree.

But Vandervelde isn’t another child building a summertime tree house, and his certainly isn’t made of haphazard boards and mismatched nails. Vandervelde, a University graduate, is one of several architects who designed elaborate tree houses for the Minnesota Landscape Arboretum in Chaska, Minn.

Vandervelde’s metal creation spirals up the trunk of a red oak, leading visitors to a perch amid the tree’s branches. The treehouse is part of the Totally Terrific TreeHouses exhibit, which opened June 5 at the arboretum. The University’s Horticulture Department runs the area, which regularly features exhibits for the public.

The tree house exhibit is open through Oct. 10, and showcases the designs of landscape architects and several firms in an effort to educate visitors about trees.

“An arboretum is about trees, and we are trying to do things that relate to that,” said Peter Olin, the arboretum’s director. “This year we wanted to bring attention to the trees, and we thought, ‘What better way to do that than with tree houses?’ “

Olin said the arboretum asked designers to submit plans for tree houses, following the rules of the competition.

“There were all kinds of restrictions, including no nailing or bolting or anything inflicting the tree,” Olin said. “And they followed that and came up with some really unique ideas.”

Twelve tree houses – of 33 submitted designs – were displayed. Ten of those 12 designs were chosen as winners and each received $2,500, Olin said.

The architects came up with various ways of creating tree houses without harming trees.

Vandervelde said his design resembles a tree’s structure and function.

“I could imagine a lot of the designs would be ground level because of the restrictions, but that seems wrong,” Vandervelde said. “A tree house is about getting people into the tree and I used the basic structure of a tree with the spiral helix to do that.”

University landscape architecture graduate Bruce Lemke built a human-sized bird’s nest with two eggs, one of which was cracked, at ground level around two sugar maple trees.

“I said I put together a focus group of birds and cats and bugs, but it didn’t work out too well,” Lemke said. “I just hoped they liked what I did and had a sense of humor because that’s what it was about.”

Other treehouses on display include a large ship caught in the trees and a “tree man” made of willow saplings with his arms around a tree.

The artists said they were amazed by the different ideas in the exhibit.

“I had one idea I was so focused on, and I looked at some of the other ones and there are some really creative and totally different directions,” Lemke said. “That was part of the fun, too, seeing how other people solved the problems.”

Families that attended the exhibit said they liked the creativity of the tree houses.

“I think it’s incredible,” visitor Kathy Kvern said. “It is a great way to show my daughter trees while integrating art with nature.”

Although the exhibit is geared toward younger visitors and their families, anyone will find connections to the art of tree houses, Olin said.

“I think it appeals to people on that basic child-like background that we all have, and I think that would be something college students would like to experience for themselves,” Olin said.