Drew Koschmann developed his love of the outdoors as a child, taking nature walks in state parks with his father, a retired science teacher. After high school, Koschmann began to study natural resources, but a side job at a local greenhouse changed his career trajectory. Now, as a head grower with 18 years of experience, Koschmann is passing down his plant knowledge as he innovates more efficient ways to grow.

After switching his major to horticulture production at Purdue University, Koschmann started an internship at Midwest Groundcovers in his home state of Michigan. By the time he graduated, they offered him a role as perennial grower. He spent eight years there, eventually taking over as nursery manager before moving to Andy Mast Greenhouses, where he served as head grower for four years producing annuals.

That’s when the head grower position at Walters Gardens opened up, and Koschmann jumped at the opportunity to get back into growing perennials.

“I had come to know Walters Gardens pretty well from working at Midwest Ground Covers, and I had purchased a lot of plants from them,” he says. “I was really impressed with the high quality that came from Walters.”

Koschmann joined Walters Gardens in 2015. Since then, he’s played a pivotal role in building the team and the automated processes that help the company produce more than 1,000 varieties of perennials in 13 acres of greenhouse space.

Increasing efficiencies

In addition to the greenhouse, display gardens and R&D beds fill out Walters Gardens’ property in Zeeland, Michigan. “We’ve really maxed out our main facility,” Koschmann says.“So we decided to look at adding acreage.” The expansion began this fall, with ongoing plans calling for “adding a couple more acres for production next year,” he says.

Meanwhile, to make the most of the space on-site, Koschmann relies on technology to optimize the greenhouse conditions for finishing various crops throughout the season.

“We’re receiving tissue culture cuttings throughout the year, so we’ve got to have warm spots in January. We’re holding vernalized plugs, so we’ve got to have cold areas, as well,” he says. “And, since we’re doing a lot of production out-of-season for hostas and hibiscus, we’re proactive in using LED and HPS lights to help them finish.”

About five years ago, Walters Gardens built a 15,000-square-foot propagation facility, referred to as the acclimation range, to house trays of fresh cuttings. Koschmann worked closely with the production manager and maintenance manager to develop the range — which is decked out with high-tech environmental controls, automated boom irrigation, heated floors, shade curtains and a fogger system.

“We’ve been happy with that [automation, because it] helps us manage the temperatures, irrigation, and humidity levels we need for the crops to finish on time,” he says.

Sharing knowledge

Throughout the week, Koschmann keeps tabs on plant progress by meeting one-one-one with his three lead growers, each of whom manages five section growers. An integrated pest management (IPM) team of three people also supports his team. During peak season, Walters Gardens supplements its staff of about 200 employees with an additional 100 workers through the H-2A Temporary Agricultural Employment program.

“That’s been really exciting to see how our section growers have been able to train H-2A labor to help with managing crops,” Koschmann says. “We’ve been working with a lot of the same employees for the past three years, so they’ve become really important in our propagation area, and every year they’re learning more and more.”

Koschmann holds growing team meetings every week to troubleshoot issues by leveraging the various perspectives and expertise of his employees. With decades of knowledge between them, this team is critical to the company’s success.

“We’ve worked really hard to hire experienced people,” he says. “The lead growers have brought a lot of talent to the team. The thing I really love about being here is if a question comes up, there are [growers on staff] I can ask to help me through.”

By focusing on collaboration between growers, staff, seasonal workers and interns, Koschmann is cultivating a strong team at Walters Gardens. Leveraging their combined expertise is key to the company’s growth and innovation.

“Growing is a team sport,” Koschmann says. “You should make your judgment calls based on advice from your team. It’s smart to surround yourself with strong talent, [people who] have skills that are different than your own, [because you’re] always learning from each other.”

Bilyj is a freelance writer based in Cleveland, Ohio.

With labor difficult to find and expensive to employ, making efficient use of the employees you have is important. Training, materials handling equipment and better working conditions can help to improve output with less labor.

Provide training for new employees. Some prospective employees have never been in a greenhouse or are not familiar with the way plants are grown. New employees should be trained and provided with a broad range of experience if possible. The training can be in the form of videos on specific subjects. It can also come from working with an experienced worker that has some skill in training.

Form small teams for greater output. Many tasks require the effort of a number of individuals in a sequence of operations. The team approach usually gets the maximum output. Giving a new employee a broad range of tasks can identify natural skills. Take advantage of these when assigning work.

Employee motivation. A worker is happier with a job that satisfies basic needs. Recognition and attention for a job well done can go a long way toward building self-confidence and esteem. Assistance with family or health problems indicates that you are concerned with their welfare.

Compensation, both pay and benefits, are usually the major factor in motivation. Salary, hourly rate and piece work are used in the industry. Salary is common for supervisors and employees that have flexible hours. Tasks such as potting and transplanting are frequently compensated by piecework. Other tasks such as watering and materials handling work better on an hourly basis.

Reduce the amount of walking employees have to do. Walking adds considerable time to the cost of plants. An average time to pick up or set down a flat of plants is 1.5 seconds. Carrying or walking can be figured at 4 feet/second. At a $15/hr labor rate, making a round trip 10’ away to place a flat of plants on a bench adds 3 cents to its cost. Walking to the far end of a 100’ greenhouse costs $0.25.

Electric carts have multiple uses. Personnel carriers are characterized by a driver compartment and additional seating for employees. They can save considerable walking time in larger operations. Cargo carriers have a driver compartment and bed area for the load and are great for moving materials. Tow tractors can have either a stand-up or seat compartment and usually a very small cargo area. Select a model that fits your operation and needs.

Conveyors speed plant movement. One of the most popular types of conveyors is the multi-section conveyor. It is made up of one section with a drive unit and a number of additional sections that can be added to provide the desired length. These work well for moving pots into and out of the growing area or for loading plants onto a long truck bed. It takes about 5 to 10 minutes to set up a 75-foot unit.

Select equipment that will pace workers. A variable speed belt conveyor also works well for potting, transplanting and packaging providing uniformity and consistency. For the medium size grower that grows mainly a spring crop of annuals or holiday plants, a transplanting conveyor can give a big increase in production. Growers have reduced transplanting costs by 30 to 40% by just installing a transplanting conveyor.

For larger operations or for growers that are producing plants year-round, there is an automatic transplanter that will fit your needs. Machines are available that will plant from 10,000 to over 50,000 plants per hour. To get maximum production, the transplanter is only one piece of equipment in a system that may include a bale breaker, flat de-stacker, tray or pot dispenser, container filler, transplanter, source tray feeder, automatic tagger, watering tunnel and associated conveyors. Once the trays are transplanted, carts or conveyors are necessary to transport the 1,000 flats/hr to the growing area. This equipment is the only way large growers can fill their orders on time.

One way to offset the increasing cost of labor is to improve the efficiency of your present operations. An efficient work area and easy method for moving plants and materials are usually the areas where the greatest gains can be made.

When walking any horticultural trade show floor, my eyes are always scanning for cool plants. What’s the next new, or new to me, plant to jump out and capture my fancy?

This summer, when walking the Cultivate ‘21 show floor, I was quickly drawn in by a couple of new caladium varieties that jumped out from the pack. ‘Burning Heart’ and ‘Hot Flash’ both had me feeling a little flushed. The colors were so unusual I had to stop and get a closer look. My first thought was, why aren’t these marketed as houseplants?

If you don’t already know, the cool kids in the world of houseplant parents are fascinated by growing caladiums indoors. One of my previous students from my UCLA Extension Indoor Plants course now runs his own plant truck in California, called The Haus Plant (find them on Instagram as @thehausplant). You wouldn’t believe me if I told you how much he’s charging for individual pots of caladiums.

Now, this isn't to say that caladiums don’t present challenges as indoor plants, especially if one expects them to stay lush and leafy all year round. But we’ll get to that in a minute.

The genus Caladium, its name derived from the Latinized Malay name kaladi, includes seven species native to South America and Central America. However, this plant gets around. Not only has the species naturalized in parts of Africa, India and other tropical areas, but there are also about 1,000 different named cultivars — likely more at this point, as I’ve probably lost count.

You’ll find Caladium spp. growing naturally along riverbanks and in bright, humid forest areas. This is why caladiums make such a wonderful shade and part shade foliage ornamentals for warm climate gardens.

While research has shown that many plants growing in tropical or subtropical rainforest type environments will put on more leafy growth before the dry winter season (thus transpiring more and potentially bringing back the rainy season), caladiums prefer to punch out and let the big trees do the heavy lifting. As day length shortens (night duration increases, which may only be a negligible change close to the equator but with increasing differences as you move away from the equator), temperatures cool slightly (depending on location) and humidity decreases in the fall season, caladium leaves begin to die down and tubers can enter a type of eco-dormancy for the duration of the dry winter season. The dormant state can last a couple of months, or much longer, depending on the conditions. When the rainy season returns, tubers spring to life again and sprout new leaves.

Now, we all know this dormancy response becomes more dramatic once you hit North America, with more significant photoperiod and temperature shifts. You can bet once temperatures get below 60° F, caladiums will want no part of it. Hardy only to USDA Zones 9-10, tubers must be lifted from the garden after foliage dies down for many gardeners across the U.S. The photoperiod changes are also more significant as you move north, and those shortening days tell the tubers the dry season is on its way.

Photo: © john | Adobe Stock

So, how do these environmental sensitivities influence their use as a houseplant? While you can certainly keep plants warm enough indoors, that may not be enough to keep them from wanting to go into at least a short dormancy. Humidity in indoor environments is relatively low, so that can trigger plants to head south for the winter. Couple the low humidity with the shortening autumn photoperiod (yes, even indoors), and you probably won't be able to stop your caladiums from taking a rest. Now, you could extend your photoperiod with grow lights and keep your caladium under glass or in a glass cabinet to keep humidity high (as savvy plant parents now do by rigging up glass Ikea cabinets and the like), but there’s still no guarantee they won’t take a nap anyway.

What I will say is that allowing your potted indoor caladiums to take a winter rest is much easier than dealing with lifting caladium tubers from the garden and storing them. When the leaves begin to show signs of dying down in autumn, simply reduce your watering until the plant goes fully dormant, clip off all the old leaves and set the pot in a cool dry place for a couple of months. That’s it. Come late-winter or very early spring, as daylengths are increasing, pop your plant back into a sunny window and start to administer small amounts of water. Once the first couple leaves begin to emerge, give your potted caladium a light dose of a houseplant fertilizer to help kick it into gear for spring.

This is a fairly straightforward process, and one that is no different from how we instruct our customers to grow and store indoor-forced amaryllis bulbs, which have a summer rest period. Yet, growing caladiums indoors still seems to be a bit of a mystery for industry pros and home enthusiasts alike. At the rate houseplant enthusiasts are gobbling up all sorts of super-challenging aroids and high-humidity Maranta and Calathea spp., I’m sure they’re willing to take on the caladium challenge.

Repurposing common outdoor crops as unusual and desirable houseplants comes down to giving consumers a few simple step-by-step instructions and helping them envision the plant indoors. If you aren’t marketing common tubers such as caladiums as houseplants, along with other bulbs and corms, you might be missing a fantastic opportunity.

Trying to control the growth of all your different spring crops can be a challenge. With so much diversity in our greenhouses, heads can spin trying to keep all the requirements for different species and cultivars straight (Fig. 1), and plant growth regulator (PGR) strategies are no different.

There are several methods for applying plant growth regulators to your greenhouse crops, including foliar sprays, substrate drenches, liner dips, and bulb soaks. Each of these methods are effective for applying PGRs, but each have advantages and limitations.

Liner dips and bulb soaks are application techniques that are used during specific stages in production or for specific crops. Foliar sprays are the most widely used application technique, such as when young plants are transplanted into their final containers.

But, it is my belief that substrate drenches must have a spot in your PGR toolbox for controlling spring crop growth. This article is going to focus on maximizing the effectiveness of PGR drenches for controlling containerized crop growth.

Why drenches?

If foliar spray applications are so ubiquitous, why consider applying PGRs with substrate drenches? First, drenches are the application of a known volume of PGR solution to each container. This can aid in improving uniformity in growth control across the crop compared to foliar spray applications. Drenches can also provide growth control for a longer duration than sprays. While the increased duration of activity can increase the chances of overregulation if too much PGR is applied, this can be used to your advantage when applications are correctly applied.

PGR?

One of the most important aspects of applying substrate drenches is selecting the right chemical or active ingredient. When applying PGRs to substrate, you need to select PGRs that have substrate activity. Ancymidol (Abide, A-Rest) flurprimidol (Topflor), paclobutrazol (Bonzi, Paczol, Piccolo), and uniconazole (Concise, Sumagic) are the most commonly used active ingredients for substrate drenches. While chlormequat chloride (Citadel, Cycocel) does have some activity when applied to the substrate, it is not labeled for use in drenches for the United States. Ethephon (Collate, Florel) is also not currently labeled for substrate drenches, but with recent research reporting the effectiveness of ethephon drenches, labels will likely be changing in the near future.

When?

Drenches can be applied at different points in time throughout crop production, from right after transplanting up to the final stretch before shipping.

Generally, drenches should not be made until roots are growing out through the substrate and touching the container wall. This time will vary with container size and plant species, but this is generally between 1 to 2 weeks. If you plan on pinching your crop, drenches are applied when the axillary branches start to grow and are between 1 and 2 inches long. Again, while the time to application after pinching will vary with plant species and vigor, this is also usually between 1 to 2 weeks.

While most PGR applications are made earlier in the production cycles, late drenches can be used to control unwanted stretch at the end of production. For instance, late drenches are commonly used on poinsettias to combat the late stretch that can occur.

Similarly, later drench applications using a lower concentration can be useful for slowing or holding baskets.

How much?

When you are considering how much to apply, the amount of active ingredient delivered to each container is a function of solution volume and concentration. First, the amount of solution applied must be proportional to the container size. As container size increases, appropriate solution volumes increase. For example, while 2 fluid ounces is recommended for a 4-inch container, 4 fluid ounces are appropriate for a 6-inch container, and 15 fluid ounces for a 10-inch hanging basket.

As with any PGR application, the degree of activity increases with PGR concentration (Fig. 2). It is important to know that PGR concentrations for drenches are generally much lower than concentrations used for foliar sprays. Though specific recommendations are beyond the scope of this article, do some research to get an idea of which concentration(s) you should start trialing in your facility.

Growing substrate components can also affect drench concentrations. For example, when blended with peat, parboiled rice hulls do not reduce PGR activity when drench applied. When PGRs are applied to substrate containing bark, PGR efficacy is reduced because bark ties up some of the PGR and makes it unavailable to plant roots. Increase PGR solution concentrations, not solution volume, when treating plants grown in substrate containing bark.

Bottom line

Active ingredients, application timing, and application volume all affect the effectiveness of your drenches. Conduct in-house trials to see how PGR drenches can improve your production.