A green-thumbed art professor in the U.S. has painstakingly created a living work of art in the Tree of 40 Fruit, a hybrid that is exactly what its name suggests.

Sam Van Aken has grafted several different stone fruit trees together to create a number of hybrids that flower in different colours and yield a wide range of fruits, including peaches, plums, apricots, nectarines and cherries.

Several young Trees of 40 Fruit have been planted in different parts of the U.S., with most of them in the northeastern part of the country.

The trees are Van Aken's version of Noah's Ark, meant to preserve rare fruit varieties that were once plentiful in central New York. He says hundreds of those varieties have nearly died out because commercial growers only mass-produce a handful of long-lasting and easy-to-sell varieties.

"We continue to lose variety and diversity in the fruit that's available for us," Van Aken said in a recent TED X talk video. "In some small way, I'm creating my own type of diversity and preservation."

Van Aken works as an art professor at Syracuse University, but he was born and raised on a farm. He says those roots gave him the know-how to create the Tree of 40 Fruit, using a wide variety of trees he acquired when he took over an experimental orchard once used by New York State University. The orchard was home to more than 250 varieties of fruit trees, many of which have not been seen in the state in over a hundred years.

"This one single orchard was the 150-200-year history of that industry, and it contained all of the heirloom, native, hybrid and antique varieties," Van Aken said.

Van Aken has been slowly shaping his hybrid trees since 2008. For each fruit variety, Van Aken snips a budding sliver of branch off the contributing tree and grafts it into a like-sized hole on the host tree. The chunk of wood is taped in place and left to heal into the tree over the winter months. When spring comes, Van Aken prunes the sliver with the hope that it will regrow as a full branch.

"I can design and essentially sculpt a tree and how it blooms," he said.

Van Aken keeps thorough records on each tree, recording when the various fruit branches flower and yield fruit throughout the growing season.

"I look at the Tree of 40 Fruit as an artwork, a research project and a form of conservation," Van Aken said.