It’s said that 90 percent of an iceberg lies below the surface. While what we can see may be awe-inspiring, it wouldn’t exist without the foundation that supports it. Strength and stability – a firm and nurturing foundation – are what make that massive chunk of ice so impressive.

Trees at Possibility Place Nursery are grown in 5-gallon, root-pruning containers.
Photos courtesy of Kelsay Shaw.

The same can be said of plants. The most breathtakingly beautiful, vital plant would be nothing without the foundation of a healthy, supportive root system. Strong, sturdy stems, lush foliage and rich blooms? They owe everything to the structure beneath the soil.

No one knows that better than Connor Shaw. At Possibility Place Nursery in Monee, Ill., Shaw’s production of native plants is all about the roots. Shaw grows trees and shrubs that are native to northeastern Illinois, along with a select group of perennials and grasses that also hail from the area. Seed is collected locally – so locally, in fact, that it comes from Shaw’s own garden and other locations within 150 miles of the growing operation.

These are beautiful, sturdy plants that have already proved their durability in the upper Midwest’s challenging conditions – hard clay soil, sweltering heat in summer and bitter cold in winter. Their provenance alone would make them suitable candidates for both a grower’s inventory and a landscaper’s palette, but Shaw doesn’t rely solely on the plants’ natural ability to thrive in their “native” soils. He pays special attention to growing plants with exceptional roots. And for Shaw, that means leaving B&B behind and employing root bag and root-pruning containers. It’s something he’s done for nearly two decades.

Root-friendly, 15-gallon bags contain encourage the healthy growth of bur oak.

“I read up on all the choices, and the root bags made a lot of sense on so many levels,” Shaw explains. “Smaller balls for bigger trees, less labor, smaller equipment and much better root systems. That being said, we went through six or seven different fabrics since 1983.”

Laying the foundation

Developing a vibrant, fibrous root system begins with seed propagation, the system for which has evolved over a number of years. And the procedures are always being fine-tuned. “It took us 33 years to develop these practices, which continue to challenge us,” Shaw says. “We have six to 12 research and development projects a year trying to tweak the system. We usually have between one and three that pan out that are incorporated into the system.”

A side row mulcher is employed to fill aboveground containers at Possibility Place Nursery.

In a nutshell, seed is propagated in flats with wire bottoms, which then are placed on wire benches. When the developing roots reach the air, they dry out and die – which encourages more roots to grow. Seedlings are placed in half-pint containers that direct root growth through air holes, and the dying-and- regrowing cycle repeats as the plants are then placed in gallon containers that further encourage a fibrous root system.

Left: Prunus virginiana (chokecherry). Center: Asimina triloba (paw paw). Right: Sassafras albidum (sassafras).

Shaw says that all propagation containers for woody plant production are reused; they usually last for four or five cycles. “We encourage our customers to bring back our 5-gallon containers and give them 50 cents per pot off their next purchase,” he adds. Root bags used for growing on and “the breakaway tray for perennial plant sales are the only things we can’t reuse.”

Growing on

Five-gallon containers are mulched in, which reduces soil temperature as well as water use.

Trees at Possibility Place are grown in root bags measuring 12 inches deep; two sizes – 12 inches and 18 inches – are employed. According to Shaw, a tree that’s transplanted with a root bag retains 60 to 70 percent of its root structure. Considering that a B&B tree retains as little as 5 to 15 percent of its roots, one can see the advantages.

Shaw compares the difference in simple terms: “When using the root bag system, the plant is always in a root-pruning container, from start to finish.” The plant is sold with the bag in place, although it must be removed prior to planting.

Possibility Place also employs a 5-gallon container program, which the company started in 1999. “It has taken us about 8 years to feel we have a good idea of how to do it,” Shaw claims. “The parameter was to put a plant in a container and never touch it again (reducing labor) until it is sold, moved to a 15-gallon or thrown out.

“The container is one of the few that let the roots escape the container,” he continues. “All the containers are mulched in. The roots grow into the mulch – this reduces watering by 50 percent. The mulching also reduces soil temperatures in the container for better roots.”

Left: A native sphinx moth caterpillar is attracted to coralberry. Right: Geum triflorum (prairie smoke).

All shrubs and trees are grown in the 5-gallon containers, and most of the trees in root bags. “Very few [shrubs] go in root bags. The difference is, we can grow a bigger plant in the field. We have recently started growing in 15-gallon containers; this system may be the future, but we will have to see.”

Native Staphylea trifolia (American bladdernut) thrives in full sun to partial sun and mesic to moist soils in the upper Midwest.

The perennials program

Native perennials, grasses and sedges are grown from Midwest seed in a practice that’s similar to woody production. “We use a Rootmaker® 60-, 32- and 18-cell flat that stair-steps from top to bottom, with air pruning at each level,” Shaw describes. “The more roots, the better the plant transplants and the quicker it grows. The industry uses a container with air pruning only at the bottom. I have been told by many people in the trade that it doesn’t make any difference between the two when growing plants. It definitely makes a difference on woodies, and I intend to find out this year on perennials.”

Selections ranging from Agastache foeniculum (anise hyssop) through Parthenium integrifolium (wild quinine) to Zizia aurea (golden Alexanders) represent the best of what the upper Midwest has to offer.

The nursery doesn’t use chemical controls for insects, mites or fungi, and this encourages birds, bees and butterflies to visit.

Years of trial and error – including many trials with much success – have contributed to a few of Shaw’s firmly held convictions. The industry is changing, to be sure, as are the plants, the people and the practices. But the roots will always remain critical.

“Growing has its own [peculiarities],” Shaw concludes, “but the other half of the story is marketing. It’s equally challenging, if not more difficult, than growing.” And while he knows it’s not the most popular view, he stands firm in his belief in the practices he employs. “I believe those entering the nursery industry will have to learn container growing,” he says, “because B&B is headed for the setting sun.”

Connor Shaw, founder of Possiblity Place Nursery

“All kinds of possibilities”

Possibility Place Nursery was established in 1978, but the Shaw family’s involvement with the land goes back to 1957, when Connor Shaw’s father – an executive with the venerable Chicago department store Marshall Field’s – moved the family from the northern suburb of Lake Bluff, Ill., to a farmhouse in Monee, south of the city. Shaw says that his father had dreams of becoming a “gentleman farmer” and believed the run-down property had “all kinds of possibilities.” The 80-acre spread evolved into a working farm where Shaw, two brothers and sister raised livestock. In 1978, the farm became home to the wholesale nursery Shaw operates today.

Nearly 70 varieties of trees are grown and sold, along with almost 70 shrub species. In addition, Possibility Place raises grasses, forbs, vines, ferns, sedges and rushes – all native to the upper Midwest and each more beautiful and vigorous than the next. The company sells both wholesale and retail; retail is by appointment only.