ISU Extension hosting gardening program

Bees are important pollinators, and that’s one reason to plant flowers like marigolds next to your vegetables, because they will increase the yield. (Andy Hallman/The Union)
Bees are important pollinators, and that’s one reason to plant flowers like marigolds next to your vegetables, because they will increase the yield. (Andy Hallman/The Union)

FAIRFIELD – Did you know Jefferson County ISU Extension has its own greenhouse and a series of 21 raised garden beds?

You might not, since the garden is well south of the Extension office, on the southern tip of the Jefferson County Fairgrounds that can’t be seen from Burlington Avenue.

Clint Mercer, the Extension office’s youth outreach educator and Master Gardener coordinator, wants to spread the word about the garden, so he’s hosting a program to tell the public about it from 5-7 p.m. Aug. 13 at the fairgrounds.

Since its inception, the Extension office’s garden has grown vegetables for The Lord’s Cupboard food pantry in Fairfield.

It’s a nice way to provide local produce to those who need it most. But Mercer sees the mission of the garden as much more than the fruit of its vines. He sees it as a great educational opportunity for Jefferson County residents to learn the ins and outs of gardening.

“There have been some great things going on in the garden, and this would be a great chance to view them in person,” Mercer said about the upcoming program.

The program will place special attention on a practice called companion cropping, which refers to putting different plants in the same bed because they are mutually beneficial.

A good example of companion cropping is planting marigolds in the same bed as musk melons. The marigolds produce a strong smell that repels insects and thus protects the neighboring melons.

Planting celery among tomatoes does the same trick because of the scent celery produces. Mercer said another advantage of companion planting is that different plants will absorb different nutrients from the soil.

Mercer has one bed where radishes are planted next to winter squash. The squash provides shade for the radishes, and in turn, the radishes break up the soil. Over time, this broken soil allows the squash’s roots to grow deeper.

Mercer said he’s planted marigolds in several of the beds because they have another benefit, which is attracting pollinators like bees, beetles, butterflies and hummingbirds.

Some plants, such as melons, see a noticeable increase in yields thanks to these pollinators.

“ISU has research showing marigolds help with different insects and nematodes,” Mercer said. “They’re easy to plant and keep their flowers a long time. Our marigolds have been flowering for months.”

In the gardens, you’ll see peppers surrounded by lettuce. Mercer said the lettuce acts like a “living mulch” by reducing soil erosion, retaining moisture in the soil, and above all, keep it cool.

“If the soil gets too hot, the plants get stressed,” Mercer said.

Some of the plants in the garden take a few years to grow before they can be harvested. This is true for asparagus, which is normally harvested at the end of its third year.

The garden sports a trellis that was installed last year for raspberries. In the wild, raspberries like to grow up trees, where they can spread out. The trellis mimics a tree by giving the raspberries a place to grow so they don’t smother themselves.

In one corner of the garden, Mercer has set up a series of three compost piles. The first pile is compost in its early stages. Mercer buries weeds, lawn clippings and wood chips. After a certain amount of time, Mercer digs up that pile of compost and puts it in the second station, where he breaks it apart with a compost fork.

Breaking up the compost and exposing it to the air helps with its decomposition. Mercer said he buries his compost because it allows worms to break down the organic matter.

After he digs up the compost and puts it in the third pile, it’s ready to be placed around the vegetables. “You especially need good organic matter in raised beds to release nutrients and cool the soil,” Mercer said.

Mercer said members of Master Gardeners help with the gardens, and he’s always looking for more volunteers to weed and water the plants. Those who are interested in volunteering or learning more about the gardens can email Mercer at or call 641-472-4166.