The Quad City Times
Written by Alma Gaul
February 14, 2016
With all the pest problems affecting many of our common trees, you may wonder what is safe to plant.
Horticulturist Andy Schmitz has an emphatic answer: the Kentucky coffeetree.
It's a native, though relatively rare, tree that typically grows 60 to 80 feet tall and about 40 to 50 feet around. It has no pests, is adaptable to urban settings, tolerates drought and occasional flooding, is fast growing when young, thrives in USDA Hardiness Zones 3-8, and can be considered "tough." It also lives a long time, from 100 to 150 years.
With all these fine attributes, you may wonder why you've never heard of it, or why it isn't more widely used in the landscape industry.
The reason is its rarity. But Schmitz, horticulture director at the 141-acre Brenton Arboretum just west of Des Moines, is out to change that.
He'll tell you more about why he loves this tree on Saturday, March 5, when he will be one of six speakers at the annual Horticulture in the Heartland event at Clinton Community College.
Other topics include pruning, honey bees, insects, sempervivums, container gardens, perennials and herbs.
The Kentucky coffeetree - so named because its seeds can be roasted and used as a substitute for coffee - is rare precisely because of its seeds. Their coats are so hard it's believed only hugh creatures such as the now extinct mastodon could break them, thus allowing them to sprout and grow.
Without creatures to disperse the seeds, the only chance for regeneration is if the seed coat is broken down by natural processes. This takes a long time and because seedlings are intolerant of shade, most don't grow.
But Schmitz knows where many of them are. For the past eight years, he and an employee of the USDA have traveled to 14 different states - Minnesota to Oklahoma - to collect seeds of the Kentucky coffeetree and propagate them at the arboretum.
He finds the trees through internet searches, contacting Midwestern universities about their herbariums (plant collections) and networking with people who work in state parks and departments of natural resources.
Schmitz' goal is to develop a collection of coffeetrees at the arboretum with various characteristics depending on where they are growing.
A specific collection of plants is as important for an arboretum - an outdoor museum of plants - as a specific collection of paintings is for an art museum.
Many arborists build reputations based on their specialties; the Bickelhaupt in Clinton, for example, is known for its conifers and Rieman Gardens, in Ames, is known for its Buck roses, hardy varieties developed by a professor named Griffith Buck.
Arboretum collections are beautiful to look at and students or scientists can use them for research.
Now that you've heard all these good things about coffeetrees, you may wonder how you can get one.
Schmitz said they can be found at nurseries, or at least ordered through a nursery. Don't look for them at mass-marketer, big box stores.
In addition, Schmitz will bring a sack of seeds to his talk in Clinton and will give them away, along with instructions on how to prepare them for planting.
One caution: The seeds of the female tree are contained in rather large pods. If you are the kind of person who doesn't like the looks of pods, or cleaning them up from the ground, you should be sure to get a male tree.
Schmitz, though, loves the pods. "Horticulturally, they are just georgous," he said. He also likes the coffeetree's coarse structure in the winter and its leaves in the summer. The tree produces what is called a doubly compounded leaf, meaning lots of little leaves regarded as one big leaf. At 24 inches long, it is the largest leaf of any tree in North America.