Strength in numbers

Millions of micro cuttings line the shelves and tables of Knight Hollow Nursery’s tissue culture lab. The Middleton, Wisconsin nursery specializes in wholesale propagation of woody ornamentals, especially specimens that have been considered difficult to clone.

Knight Hollow Nursery was founded in 1981 by Deborah “Deb” McCown. Currently, Elizabeth “Liz” (Dunham) Erickson runs the business as president and part-owner. It’s a rare example of a mother-to-daughter succession. Family-owned and operated from the start, Liz has maintained the reputation her mother built while developing new relationships to grow the business.

The business started with Deb propagating Rhododendron and Kalmia. Her husband, Brent McCown, is a professor emeritus at the University of Wisconsin-Madison, where he developed a specialized woody plant medium. This was a crucial part of Knight Hollow’s success as one of the first woody tissue culture labs. They are both still involved in advisory roles.

The nursery works with a wide variety of breeders and marketers to bring in new plants while stocking a steady selection of the classics.

The approachable option

Liz says there are a few misconceptions about tissue culture in the industry, but it isn’t that different than any other type of propagation.

“Sure, we grow in a lab but the principles are the same as in a greenhouse or in the field,” she says.

“It seems that TC is becoming more approachable than it used to be for more growers,” Liz says. “It’s not like we’re the wizard behind the curtain anymore. Especially since we root and acclimate the majority of our product into 200-cell plugs, making it easy for more nurseries to take our plants.”

Oregon’s Microplant Nurseries sells in vitro plants and North American Plants offers larger plugs in 144, 50 or 32-cell trays.

Knight Hollow fills a niche by splitting the difference and providing an in-between option. Knight Hollow’s plants are sold in 200-cell Jiffy Preforma plugs, which is a standard size that nurseries are capable of handling with ease. Also, Knight Hollow’s minimum order is 5,000 per plant, per year, much lower than some other labs.

Rooting the plants themselves is another way Knight Hollow strives to be approachable. Most nurseries don’t have the facility to handle a tender plant right out of culture. If they had to root it themselves, their losses would be fairly high.

“A lot of nurseries, they’re not going to be able to baby something along like that,” she says. “Our product, they can start running with it as soon as it hits the ground.”

Knight Hollow’s plants are acclimated to low humidity and high light. After being planted from Knight Hollow’s cultures, they spend a few weeks in the indoor grow room, then a few more weeks in one of two small greenhouses, which are used to harden off the plugs before being graded and shipped.

The challenge of timing

The biggest challenge for Knight Hollow is meeting its customers’ timelines with the variety of products the lab offers. From rhubarb to birch, each type of plant needs to be manipulated at a slightly different time or using a slightly different technique to end up perfect.

That’s the service Liz and her team provide. She compares it to cooking a meal with multiple components. Some items need to be cooked longer than others or at a different temperature.

“It’s like when you make a five-course dinner,” she says. “You have to have the meat, the noodles and the vegetables all ready at the same time. But they’re all very different. It’s the same thing here. We have to have the roses and the Cercis and whatever else ready at the same time.”

During COVID, when logistics became a mess for the entire supply chain, Knight Hollow lost a few pallets in the Pacific Northwest. Since then, they started filling up a big truck and driving it out to Oregon themselves.

The nursery has about eight customers in the Portland area, so to make it work all the plants for all of the customers must be ready at the same time in order to head west on that truck. Liz says it’s a way to guarantee the plants won’t freeze and will arrive at the right place at the right time.

One of Liz’s goals for Knight Hollow is to sell more plants during the less busy times of year. So when she is approached by someone who wants a new plant, her first question is when do they want it? Can they take it in late summer? Can they take it in the fall? That has worked out for some customers and some products. Specifically, woody ornamentals like Lilac that flushes new growth, then shuts down and grows a ton of roots.

Knight Hollow works with several Southern customers that have longer growing seasons. Texan customers, for example, can take a delivery of plugs in August and still have plenty of daylight and warm temperatures. On the other hand, Knight Hollow can have plants ready in January if a customer is able to receive them.

“That’s one of the advantages of running a TC lab,” she says. “You can have plants ready any time of year. They don’t know what season it is. In the culture room, it’s always 76 degrees.”

Some of Knight Hollow’s customers do take deliveries in the middle of winter. Again, shipping is a challenge. One frigid year, Liz says, the nursery shipped a few pallets of rhubarb to Ohio. The shipment got lost and eventually arrived back in Wisconsin looking like frozen salad.

The need for growth

In 2019, just before COVID hit, Liz came to a conclusion. She was continuing to take more leadership over the business, and felt she had a clear view of the future.

“I realized this company either needs to grow or it’s not going to survive anymore,” she says. “We were at that threshold.”

Travel became her top priority. She visited as many customers as she could.

By doing the legwork before the pandemic began, when the world shut down Knight Hollow was ready to get to work.

“It was a really good year of travel and then it wasn’t,” she laughs.

During her travels, Liz really focused on expanding the number and type of brands Knight Hollow collaborates with and finding key people that work within those companies. She has developed partnerships with Proven Winners, Star Roses and Plants, Anthony Tesselaar Plants, Plants Nouveau, the Chicago Botanic Garden, the University of Rutgers and more. Almost every week she hears from those contacts, and they’re usually asking her if she can try one of their new plants.

While growth is great, keeping up with it is a challenge. The difficult part is figuring out how to bring new plants on quickly and responsibly, without a dip in quality.

Liz has 10 employees as Knight Hollow rolls into its busy season. Customers want their plugs in February, March and April so they can size them up into containers or eventually into the field by summer.

Knight Hollow is lucky to be close to Madison and have the University of Wisconsin right down the road. Generally, Liz is able to find qualified candidates from posting jobs at the UW site. Lately, she’s had 4-5 college student employees at the nursery who have stuck around for 2-3 years. Considering that’s half her workforce, it’s been a huge boon to not have to retrain a crew each year.

Woody propagation tactics

Trying a new plant in tissue culture is always a little scary, Liz says, because you never know exactly how that plant is going to respond. It takes time, as well, to produce clean stock.

When Knight Hollow receives a new plant for propagation, it’s usually a few small potted plants. If they receive 10 2-gallon pots, they will put them in the greenhouse and cut them back to flush new growth. Then, they’ll take tissue from the plant and put it into a sterile culture.

Once it’s clean, the next step is to get it stabilized and growing at a specific multiplication rate. Some plants will double every three weeks. Others may triple every four weeks. The exact amount of time needed to get the plant from the greenhouse into a stabilized tissue culture product varies based on several factors.

This is why Liz says it’s extremely important to manage expectations with clients. One way she does that is through communication. Even when a customer hasn’t asked how his or her plants are doing, she will send a text message with a photo and a quick note to show progress – good or bad. These updates help keep the customer in the loop. With plants like Cercis or Carpinus that take longer to stabilize, communication is critical to meeting client expectations.

One of the biggest differences between woody and herbaceous tissue culture propagation is the difficulty of getting a viable tissue sample that will work in culture. When a customer has a great plant specimen, but it’s five feet tall, it’s harder to get the juvenile tissue that is needed. As a result, the process takes longer. Getting a plant to root is more difficult, too. Depending on the plant, it may need some TLC.

“Some Hydrangea quercifolia, they’re going to root if you breathe on them,” Liz says. “But the Cercis are not easy to root. They take twice as long as most plants, even that I have here at a woody lab, let alone an herbaceous product.”

To make matters more difficult, Cercis often need hormone help. In the lab, Knight Hollow technicians can increase the hormone level so the plant divides rapidly. However, there is a direct relationship between cytokinin and the auxin. So her crew lowers the cytokinin level for the last round before planting so the plant roots easier when it’s taken out and it needs to produce auxin to root.

Another tactic Knight Hollow uses with more stubborn woody plants is the use of Indole-butyric acid, or IBA. Depending on the crop, Liz’s team may spray a couple rounds of the IBA rooting hormone.

A successful succession

Succession planning is tough and fraught with emotion, especially within family businesses.

Once Deb started letting Liz take over the customer relationships at Knight Hollow, she knew her mother was getting ready to pass the torch. That’s because in this business, while the plants you grow are important, the people are what’s really important.

“You sell a relationship; you don’t sell plants,” Liz says.

Networking with others in the industry who are going through or have been through the process helped immensely.

Brian Decker, president of Decker’s Nursery, and a fellow IPPS member gave her some valuable advice. Don’t be afraid to seek professional help. Get an attorney, a mediator or neutral third-party with a cool head your particular situation needs.

“Generally when they built it from scratch, it’s their baby, and they’re never really going to let it go,” Liz says. “And I had to realize that that’s OK. Everybody’s going to have their spot here.”

Here are Liz’s keys to a successful succession: Patience first. Be kind. Liz received this advice from Ross Strasko, president of Creek Hill Nursery, and a fellow IPPSer.

“Be kind, because this was their baby for many, many years and you coming in and taking control can be scary and intimidating,” she says. “Change is really hard.”

The second key is planning. Take time to plan with the outgoing leader, again with patience.

Third, give value to what that person still does day to day. He or she is still important and still has a role, but it’s not the same as it was.

Last, make sure the employees know what’s happening, so they won’t be scared. Communicate that changes will be slow and take place over many years.

Liz just finished a one-year term as president of the International Plant Propagator’s Society for 2023. She’s currently serving as past president in the organization and loves spending time with her fellow propagators.

She says the face-to-face-networking at events like MANTS, Cultivate and Farwest and being part of organizations like IPPS are vital. Click here to read Nursery Management magazine's MANTS 2024 recap.

“As I go there, of course you visit all the specific customers that you want to see and just make yourself present,” she says. “‘Who’s this girl from Wisconsin?’ It goes hand in hand with the succession. I can say ‘You probably knew my mother Deb, but this is the face of the company now. And this is what I can provide.’”

For more: www.knighthollownursery.com