CINCINNATI, Ohio – Keystone Flora, owned by Steve Slack, has been growing and selling native plants since 2005. The 3.5-acre business is a haven for pollinators and other invertebrates.

“We grow all native plants and avoid cultivars,” Slack said. “A cultivar is a native plant that has been altered to change its size shape or color for human reasons. We grow plants and are particularly concerned with invertebrate conservation, pollinators, butterflies, moths, beetles, bugs, everybody.”

Slack got interested in native plants while volunteering for the Native Plant Society in San Francisco. When he moved to Ohio, he found native plants growing everywhere in the landscape but few native plant nurseries. So, he started Keystone Flora, located in a unique area in the Mill Creek Valley called Wooden Shoe Hollow. The area was settled by German immigrants who wore wooden shoes for gardening. It is still home to many greenhouses.

“We grow shrubs and forbs (flowering herbaceous plants) many of which are prairie species,” Slack said. “They were originally growing anywhere from 100 to 150 miles from Cincinnati. We have a few things from Indiana, Adams County, and mid-Ohio. Full sun or shade plants. We also have a limited supply of flats of native plants for the Conservation Reserve Program for encouraging pollinators on fallow farmland.”

Slack plants almost everything from seed in the fall. The plants are exposed to the elements. Snow sits on them in the winter and they come up in the spring, he said. The more snow, the better. They are planted in one-gallon trade pots and are not covered.

“Most of them survive pretty well,” he explained. “There is always going to be crop loss but that is the technique we use. We don’t use any chemical fertilizers or herbicides on our native plants.”

Slack encourages his customers to use sheet mulching so they can enjoy their gardens and avoid weeding. You remove as much weed material as you can from the garden plot, put down cardboard and just enough wood chips to cover the cardboard, and then poke holes in the cardboard where you want to put a plant.

“If you have an existing garden you can go around with multiple sheets of newspaper or cardboard and place it around your plants, making sure to overlap all of the edges so no light hits the ground,” he said. “You will save yourself hours of weeding in the first two or three years.”

In the vegetable garden, which is for Slack’s personal use and not for sale, he uses a technique that is thousands of years old called hugelkultur, that is, hill culture. It’s mimicking the forest which recycles its own waste.

“We dig one-and-a-half to two-foot trenches or holes and we put logs, branches, wood chips, and leaves,” he said. “Then we put soil back on top for our raised bed. Everything tends to grow very well in a situation like that because you’re adding air, and carbon into the soil and also moisture retention; when the plant root gets down there, they exchange nutrients with the microorganisms that are working on the rotting wood.”

That creates a living soil and many plants will not need as much fertilizer in that kind of situation, he explained. Science is finding the same to be true for cover cropping, that you can save money on inputs if the soil has been tended properly.

Meanwhile, a plethora of bees, butterflies, moths, and other winged creatures are buzzing on the native goldenrods, asters, coneflowers and more blooming on the property. And the phone rings frequently. You need an appointment to visit Keystone Flora because of limited parking.

How does Slack market his products? “Not very well, I think,” was his reply. He spent a recent winter developing a website. A friend does the Facebook page. Keystone Flora has many repeat customers. The place pretty much sells itself by word of mouth.

For information visit keystoneflora.com.