Sam Van Aken once envisioned a tree with blooms of pink, purple, fuchsia and red that would bear 40 different kinds of fruit. Today, that tree is a reality.

"I'm an artist. So the whole project really began with this idea of creating a tree that would blossom in these different colors and would bear these multitude of fruit," he told NPR.

Van Aken, a professor at Syracuse University's College of Visual and Performing Arts, has spent nine years working on his Tree of 40 Fruit, and now 14 such trees exist.

He didn't create them through genetic engineering though. Instead, he's using a technique that's thousands of years old: grafting.

Grafting involves collecting young shoots or cuttings from trees and then inserting these budding branches into strategic points on a base tree.

These grafts are taped into place and allowed to bond with the tree, drawing water and nutrients from it like any other branch. If the grafts take to the tree, they'll start to grow again in the spring.

The Tree of Fruit looks like any other fruit tree until it blossoms in the spring in a variety of colors. Sam Van Aken courtesy of Ronald Feldman Fine Art

According to Van Aken, grafting is often successful because of the similar chromosomal structure of stone fruit trees.

A variety of peaches, plums, apricots, nectarines, cherries and almonds grow on the tree. Sam Van Aken courtesy of Ronald Feldman Fine Art

Stone fruits are those with a pit in the middle that surrounds the seed. Examples include apples, peaches, cherries and plums.

Van Aken has worked with 250 types of stone fruit and says his project has really become "about preserving some of these antique and heirloom varieties."

In 2011, the Tree of Fruit produced a colorful variety of plums. Sam Van Aken courtesy of Ronald Feldman Fine Art

Today, his hybridized fruit trees are located throughout the country, but he plans to soon plant an entire grove in Portland, Maine.

“Part of the idea for the Tree of 40 fruits was to plant them in locations that people would sort of stumble upon," he told National Geographic.

Another recent example of grafting is the TomTato — a plant that produces both cherry tomatoes and potatoes — which can be purchased by any gardener.

Also, many commercial fruit trees are grafted for mass production. Farmers choose a tree that will grow well in their climate and then other trees' seedlings are grafted onto the base tree’s branches.

In San Francisco, guerilla gardeners also graf fruit-bearing tree limbs onto fruitless trees along city sidewalks.

Learn more about the Tree of 40 Fruits in the video below.