Northern Exposure

Illustration © 4kclips | Adobe Stock

This summer, I attended the Perennial Plant Association’s National Symposium in Niagara Falls, Ontario. As part of the event, I was able to tour several southern Ontario nurseries. Situated along the Niagara Escarpment, these growers have advantages but also unique challenges.

Formed over millions of years through erosion, the escarpment is an ancient lake bed, lined with limestone. This creates a challenge for growers, as the soil pH is high in alkalinity, typically reaching nine or even 10. You won't see any blue hydrangeas growing in that soil.

Many people associate Canada with cold winters, but southern Ontario also has a humid, tropical climate in the summer. Monsoon-like rains are common, and the heat can be oppressive. Let’s take a look at how three nurseries (and a research station) have adapted to thrive in the Niagara region.

Sheridan Nurseries | Norval, Ontario

Sheridan Nurseries was founded in 1913 on 100 acres of land in Sheridan, Ontario. Today, between Glen William and Norval, Ontario, the company has 900 acres of land on which it produces 1,200 cultivars of perennials and hardy nursery stock. Sheridan grows and ships 1.8 million plants annually to markets across Northeastern North America, as well as supplying its own eight retail garden centers.

Andrew Barbour is director of Sheridan Nurseries’ Norval farm. The Norval facility is 83 acres, with 29 houses and 160,000 square feet of heated growing space. More than 600 different perennial varieties are grown at Norval, with new introductions every year. The crew is responsible for 700,000 plants shipped out each year.

It’s also where 60% of Sheridan-grown products are propagated. Once cuttings are prepped for sticking, Ellepot trays move down a conveyor until they reach a worker, who sticks the cuttings into the trays, then places them back on the belt. They go through a quick wash, then are stacked on rolling racks.

“The old-school method was just working at tables,” Andrew says. “Adding a little bit of mechanization gave us a bump in units per man hour but not a great deal.”

A conveyor belt system is used to move plants around the facility, from potting to shipping. The potting setup itself is fairly low-tech, with a Javo carousel potter and the movable conveyor belts, but it is very efficient. Sheridan also has an AgriNomix trimmer with a useful vacuum attachment that sucks up the trimmings into a canister, which can be easily emptied when it’s full. This saves a ton of labor, Andrew says. It’s on wheels so workers can easily roll the trimmer to where it’s needed. Conveyor, knife and vacuum speed can be adjusted from levels of 0-10. There are also three-way switches for the blower and the trimmer.

“A lot of our new growers love the technology and want to work with tech,” he says. “It becomes almost a mandate. It becomes something we need to get them engaged.”

Sheridan Nurseries does occasionally have to deal with resistance to change with some of the new technology coming on board. There’s a bit of an ‘if it isn’t broken, don’t fix it’ attitude. But Andrew sees that situation as an opportunity to take the best parts of the past and improve upon it. Trying to blend the two approaches is a challenge, but it’s one Andrew believes he’s uniquely equipped to handle.

“I’m not old enough to be considered old-school but definitely not new-school,” he says. “I’m right in the middle, which I think is a great place to be, because I can help mentor some of the younger growers and also understand where the older growers are coming from and what their philosophies are.”

Sheridan takes every precaution with its boxwood, from sanitizer shoe baths to quarantined bays to keep their plants free of the boxwood blight pathogen and the box tree moth.

For more: www.sheridannurseries.com

Maple Leaf Nurseries | Jordan, Ontario

Maple Leaf Nurseries is a 300-acre operation, with 190 acres of field growing, a 3-acre greenhouse, a 2-acre liner range, 1-acre prop house/potting greenhouse and a 60-acre container yard. The container yard has 137 houses under poly, with a total area of 1 million square feet. The nursery grows 1,300 cultivars in pots ranging from 8 inch to 20 gallons.

Owner Ted Sikkema says Maple Leaf really ramped up propagation efforts when they became a Gold Key grower for Proven Winners. The existing facility was showing its age and reaching the limits of what it could do, so he decided to build a new transplant facility/holding area. Maple Leaf also built a new liner range that he says helps mitigate the effects of Ontario weather, mainly heavy rains and extreme cold.

“If you’d seen the weather we’ve had here the last 10 days, you can hardly keep plants healthy when they’re really young and small,” he says. “So now we can control the amount of water it gets, control the wind, control the temperature, overwintering and everything.”

Most of Maple Leaf’s field production is Taxus, cedars and boxwood. Mike Sikkema leads the propagation team at Maple Leaf, which averages 13,000 cuttings per day. He has 10-15 propagators, depending on the time of year. The fastest can do 2,500-3,000 per day.

The prop house has an Argus system for environmental controls. It handles vapor pressure and shade controls. The automated system measures watts per meters squared per second, and if it hits the specified threshold, it increases the amount of shade. All flowering shrubs are watered by misting. However, for hardwood propagation, which Mike does in November and December, he waters directly once a week and mists the areas the plants aren’t in to keep humidity up.

For winter propagation, the Maple Leaf team puts a 2x6 frame around plastic skids that are also used for deliveries. They put an inch of peat at the bottom, then fill the rest up with concrete sand. They make a line with a trowel for the cuttings and can fit 1,300 plants in a box. It’s a system that has been working for them for 30 years.

“Concrete sand is good for drainage and it’s cheap,” he says. “All our hardwood material goes in the field so you can grab a big chunk of them and shake them. The sand comes right off, and it’s all bareroot.”

Mike uses a similar mix of perlite and sand for boxwood, or at least he did. Because of the box tree moth, nurseries in Ontario can’t ship boxwood across the border. They can’t even ship outside the province without a movement certificate, which requires an inspection.

Maple Leaf Nurseries top dresses all of its containers with rice hulls. Ted says the weed suppression works so well he doesn’t even need a weeding crew anymore.

For more: www.mapleleafnurseries.com

Verbinnen’s Nursery Hamilton, Ontario

John Verbinnen, the second-generation nurseryman leading this Ontario nursery, started in horticulture when he got a job at Groen’s Nursery in 1978. John and his wife Cindy purchased the nursery from her father, Henry Groen, when he retired in 2000. They renamed the business Verbinnen’s Nursery.

Henry Groen established the business in 1965 and in the early days, it was mostly liners and root stock. Today, the business has 60 employees and grows 1 million seedlings a year. Verbinnen’s specializes in growing native trees from seed. John noticed the demand for native species steadily increasing and adjusted the nursery’s focus to fill that niche.

Recently, Verbinnen’s switched to a new liner production tool: Growcoons. The Growcoon is a biodegradable web with an open net structure. It goes inside each cell in the plug tray before it’s filled with growing media. As the plant roots out, the Growcoon binds the root ball together and provides structure for the roots to continue growing.

Jonathan Verbinnen, a member of the family business’ third-generation, says they made the switch because it provided the air root pruning they needed in a more sustainable and cost-effective way. After seeing it in the Netherlands this spring, they were impressed that there was no microplastics in the product and that it met the stringent standards needed for the OK Compost and OK Soil certificate carried out by TÜV Austria and used throughout Europe.

There are a few different “recipes” for Growcoons. Growers can decide which one they want based on how fast they want the webbing to degrade, relative to pH, moisture and air exposure. Verbinnen’s is trialing two recipes; the standard and a more progressive recipe that is supposed to break down faster. Jonathan showed a trial from the progressive recipe that was potted June 22, about a week before the visit.

“It’s still there but not strong anymore,” he says. “It rips pretty easily. By comparison, the regular recipe is a little bit tighter, more stiff.”

Verbinnen’s found a novel solution to the problem of wind blowing over containers: garage doors, cut horizontally and stood up with concrete blocks at the joining spots. The doors are sturdy enough to block the wind and keep all the pots upright.

In 2017, Verbinnen’s nursery expanded to include online e-commerce with Ontario Native Plants. This retail effort is limited to 100 available species. Customers must make a four plant minimum order and prices are typically $6-8 per perennial, John says. Each container is shipped with a coco fiber mat on top to retain water.

Milkweed and rudbeckia are the two most popular plants with ONP customers. All plants grown at the nursery come from Ontario source-identified and genetically unique seed. Because of the desire to keep native plants where they’re native, they won’t ship outside Ontario.

For more: www.verbinnens.com; onplants.ca