“One man’s trash is another man’s treasure.” An idiom we have all heard many times in reference to a product or material unwanted by some but prized by others. In many cases, bark and other tree products fall in this category. The scope of this article (and series) is to provide an overview of some of the more well-known and perhaps lesser known uses of one of nature’s most valuable and abundant resources — bark. Special emphasis will be made on pine (Pinus sp.) bark, but other bark species will be highlighted, as well. The function, utility and reliance that the horticultural industry has on bark materials is pretty comprehensive. Let’s take a look at some valued aspects of bark and bark products including aesthetics (ornament), soilless substrates, synthetic turf infill, landscape applications, container mulching and fuel sources.

Ornament

Peely, flaky, blocky, ridged, furrowed, stringy, smooth, warty, on and on the adjectives could go to describe the uniqueness and beauty that tree bark can provide to a landscape, forest or specimen planting. Often the highlight of a winter landscape or the focal point of night up-lighting, the use of trees in landscapes specifically for their bark is a long-standing tradition. Highlighting various pine trees, the bark of P. sylvestris (Scots pine) and P. bungeana (lacebark pine) have stunningly colorful bark on mature trees (Fig. 1) and are used as specimens in landscapes across the globe. Not to be forgotten, the mature platy bark of our native P. tadea (loblolly), P. palustris (longleaf), and P. elliottii (slash pine) add incredible texture and boldness to mature landscapes. While other horticulturally prized genera may be more known for their extravagant bark displays, I argue that some members of the genus Pinus can rival any others.

Soilless substrates

The backbone of the horticulture container plant production industry, soilless substrates are one of the advancements that have allowed crop production to be as efficient, economical, and successful as it is today. Not exclusive to the nursery industry, bark materials are used in numerous garden soil or substrate products and applications. The nursery industry can however stake its claim as the originators of bark-based materials as the predominant, and in many cases, sole source of growing material. Dating back to the production of nursery plants in egg and coffee cans, the switch from mineral soil to bark-based substrates was a turning point in the container production world. Fast forward to today and bark substrates remain the dominant player in outdoor container production. On the west coast, Douglas fir (Pseudotsuga menziesii) bark is utilized while the eastern half of the country rely on pine bark as the primary source of feedstock for substrate production. Large bark yards can be seen across the Southeast where pine trees are prevalent (Fig. 2A). These bark producers source their raw bark from lumber yards, paper mills and other forestry operations. Bark products undergo various processing, handling, aging and formulation steps to create the consistent and functional bark substrates that nursery growers rely on. Growers will often incorporate various additives to their substrates on site at the nursery (Fig. 2B) or rely on the supplier to make these additions prior to shipping. Substrates are often tested for chemical, physical and biological properties to ensure quality control (Fig. 2C). Recent advances in bark engineering (to be thoroughly discussed in future articles) allow substrate producers to create substrates of any air, water, or density parameters a grower could want for any container type or size, irrigation delivery method, production system, etc. (Fig. 2D).

Bark products are also heavily used in greenhouse substrates, as well as consumer soil and soilless products (Fig. 2E). Many professional substrates for floriculture production, vegetable production and more recently Cannabis and small fruit production (blueberries, strawberries, oranges, figs, etc.) are using bark as one of the main constituents with peat moss. The bark in these mixes provides additional airspace porosity and drainage, which is often desired to improve production management strategies and control plant growth. The aforementioned advances in bark engineering and formulation practices now allow specific bark products to be made with specific sizes and properties suitable for orchid production, woody cutting propagation or any other niche production need.

Cork products

Maybe one of the coolest and most versatile tree barks in the world, cork has many functions and attributes. The cork oak (Quercus suber) is a medium-sized evergreen tree native to Southwest Europe and Northwest Africa with 50% of the world’s production (cork plantations) coming from Portugal alone. Cork is produced by the cork cambium in the outer bark of the tree, and is considered a natural and renewable raw material. Beginning at around 25 years of age and for as long as 200 years, cork trees have their bark harvested every 8-10 years (Fig. 3A-D). The harvested cork, as witnessed during a visit to a production facility in Espinho, Portugal, is stored as large slabs outdoors before processing into wine bottle stoppers (Fig. 3E) flooring, cork boards, fishing bobbers or a thousand other products. Waste cork from these primary industries is further processed to make cork granulates (Fig. 3F). This granulated cork can be used to make filters, insulators, clothing materials (shoes, handbags, bowties, etc.). Horticulturally, these granulates have been used as an aggregate in peat-based greenhouse substrates and top-dressing materials (alternative to vermiculite) for seed germination in plug trays. There is also an organic infill product (Corkonut from GreenPlay) used in the synthetic turf industry that use cork granulate as a component in the infill.

Landscape usage

One of the most visible and traditional uses of bark is as landscape mulch materials. Mulch and bark producers make various grades or type of landscape bark-based mulches with the three most common being shredded (double or triple), mini-nuggets, and large nuggets (Fig. 4A). Available as bagged products or in bulk loads, bark mulches can be one of the most decorative options for landscaped areas in both the traditional/original brown color or dyed. Unlike some other mulch materials, bark products do not blow or wash away easily. Bark products degrade rather slowly and add organic matter to the soil once they do decompose (Fig. 4B). Some bark mulches can be applied to landscape planting beds in unique (very specific and strategic) ways as seen in Fig. 4C-D where large bark planks are fitted on the ground in single layers to provide both a patchwork aesthetic look as well as providing the reliable weed control and moisture retention that mulches are known for. It’s a common practice seen in Central America and Europe, but rarely here in the U.S., but one that could be considered and desirable in high-end or well-manicured landscapes and highly visual planting areas.

Other uses

Bark as a container mulch (Fig. 5) is a practice that has gained attention and popularity in the past several years — container surface mulching in both plant production systems as well as post-production retail (consumer) use has increased substantially. In nursery production systems, mulching containers is used as a method of weed control as well as moisture retention. In addition to bark other materials including wood chips, rice hulls, and processed low-value trees have been used for this purpose. A lot of research has been published (and available) outlining the benefits of mulching containers as a weed control practice as well as instructions/guidelines on application methods (timing, depth, etc.). More recent and current research is aimed at quantifying the benefits of these container mulching applications on water retention (decreased substrate evaporative losses) during production and reduction of water stress (drying out) in post-production retail settings. There are wood and bark products specifically made and marketed for sale for these purposes, something I first witnessed in Europe where this practice has been common for many years. Lastly, use of bark nuggets as decorative container mulching is becoming more common (Fig. 5) and a practice adopted by many garden centers to enhance the aesthetic appearance of container shrubs, trees, and indoor plants in containers.

Bark as a fuel source has been common for many decades across the county (and world). While bark can’t compete with fossil fuels for burning efficiency, it has been incinerated on a large scale since the 1970s. When burned pine bark consists of 55-66% volatile matter, 30-50% fixed carbon and 0.25-4.0% ash (depending on bark species, age, etc.). The bark ash (often referred to as bottom ash) from incinerators has been used as additives to garden soils, farmlands and potting soils for decades. Most recently, biomass subsides authorized by the Food, Conservation, and Energy Act of 2008 (the 2008 Farm Bill) threatened to increase the price of raw bark and other forestry resources. The resulting Biomass Crop Assistance Program (BCAP) was a result of the need to meet alternative fuel usage goals that were outlined in the 2005 Renewable Fuel Standard legislation. The BCAP had the original intent of creating incentives for new clean energy biomass fuel sources including pine bark used to make mulch and substrate/soil products. The proposed $45 subsidy per ton of woody biomass would have more than tripled the price of bark going to the horticultural market at that time. Other biomass materials also mentioned within this program included bamboo, miscanthus, switchgrass, wood sawdusts and fibers, among other forestry and agricultural biomass materials. Fortunately, due to lobbying efforts by many in the horticultural industry bark supply streams intended for horticultural use were exempted from this subsidy program.

Research on bark usage and products (substrates and many others) continues feverishly today around the globe. The reliance that many in the horticultural industry have on bark materials continues to increase as the offerings and value of the materials increase. Our usage of bark products provides an end-use or value-added use to raw materials that may otherwise have little or no purpose in the overall biomass utilization stream associated with the sustainable use of our forest resources, often referred to as cradle-to-cradle. So, while bark may be trash to some it sure does provide benefit and livelihood to many others now and well into the future.

Dr. Brian Jackson is an associate professor and director of the Horticultural Substrates Laboratory at North Carolina State University. Brian_Jackson@ncsu.edu

We caught up with Todd Baker, owner of Baker’s Nursery in Bayfield, Ontario, Canada, to find out which parts of his nursery are automated. Baker’s Nursery grows young plants for growers in eastern North America. Plants are propagated by cuttings and divisions, as well as tissue culture. Baker and his team grow tree liners in containers; grass plugs and perennials in plugs up to quarts; and woody cuttings in plugs and quarts. Field production for grass and perennials totals 15 acres along with half an acre of greenhouse space and a quarter of an acres of outdoor production space. The nursery is active about 10 months a year with a staff of four to 10 people, depending on the time of year.

Nursery Management: At what point did you realize automation was needed? Was it due to a labor shortage or an efficiency problem?

Todd Baker: It had more to do with the fact that we are very hands-on in our business and prefer to work smart vs. hard. We have been fortunate to have always had a reliable local labor pool. In the past, we had 30 staff at peak. Now we are usually less than 10. And looking at systems has been a sideline hobby for years. I have always sought ‘flow’ in the work processes.

NM: What did you finally decide to implement?

TB: The investments we have made are designed to eliminate pinch points or quality traps. The vacuum trimmer, which we began using three years ago, allows us to quickly process many plants with almost perfect consistency. Last season we installed a pot/flat-filling machine. This year’s investment has been in RFID cloud-based inventory and sales management.

TB: Our nursery is a small, boutique young-plant operation. The annual investment is usually $20,000 to $40,000. Payback? Well, it starts with ‘Will this improve the quality of life of me and my staff?’ Less bending, lifting etc. Every business has jobs nobody wants to do. I don’t want to do them, either. Payoff can be measured two ways: costing you less for the same task finished or, my preference, more money coming in from the same task/investment/space etc. Don’t forget about being able to take advantage of timing. If the perfect window for an operation is one day long and you take a week, you are diminishing the potential value of your crop.

NM: How has automation changed production?

TB: Each piece has its own story related to changed production, but the common denominator is that they make the work faster and easier. Happy people do better work.

NM: What are the pros and cons?

TB: Pro: machinery allows repeatable consistency. You can develop written protocols for the tasks which eliminates uncertainty. Cons: Sometimes the noise interferes with pleasant conversation. Setup time can be variable depending on how familiar staff are with the changeovers .

NM: What is your expected return on investment (ROI) of these investments?

TB: The trimmer was a $20,000 acquisition cost. We compared how long it took to hand-trim 1,000 quarts vs. the trimmer. We found it saved $10 per 1,000 plants compared to the manual version we had set up, including trimming by an experienced staff person and cleanup of trimmings from the walkways. With the trimmer we pick up the plants, trim and set down. The $10 per 1,000 didn’t include the extra jobs completed. We removed any culls or dead plants. Now we’re able to set down full trays and have a more accurate inventory count. The space recovery, inventory accuracy and simplicity are worth more than the savings. Not to mention the skill requirement is lower and the output is 100% consistent. So, if I estimate the savings of $10 per 1,000 plus another $15 for the consolidation/inventory accuracy, the trimmer is paid after 800,000 plants have been trimmed. Our woody plants get trimmed twice, and now that we have it, we also trim our 72 trays out of propagation as well.

For more: www.bakersnursery.ca

The American Rose Trials for Sustainability (A.R.T.S.) is here to help the industry and consumers identify the strongest performing roses for their region through our independent scientific trials held at botanical gardens, parks systems and universities. How often have you seen a national ad for a beautiful new rose and asked yourself, “Can we grow that here?” Questions naturally progress to: Will this plant be cold hardy; Does it demand too much water for our arid climate; Can it take our intense summer heat; or Can it take our wet springs? Growers recognize and appreciate that not all plants grow well in all places. The challenge with a nationally loved and distributed plant like the rose is finding varieties that do well in your region. It’s important to find a trustworthy and independent voice that has grown those cultivars in your region to help guide you.

The A.R.T.S. team is made up of scientists, public horticulturists, nursery growers and extension professionals. Our goal is to identify which roses are the most pest resistant, drought tolerant, low maintenance, vigorous and beautiful for each unique U.S. climate region through our regional tests, which are done with high scientific standards. We grow the roses under low input conditions without pesticides and evaluate them monthly during two growing seasons. They are rewarded for parameters related to their health, flower power and plant form. Test roses must perform equal or better than the industry standards planted with them to earn an A.R.T.S. Local Artist award and be recommended for a particular region.

Instead of using the USDA Hardiness Zone Map to delineate regions, we use the Köppen climate system as it accounts for both temperature and precipitation levels and the timing of each. This system has been the go-to resource for ecologists studying communities of plants and the overall ecosystem. The USDA cold hardiness zones, although helpful, only take into account the lowest minimum winter temperature. The Köppen climate system is a more comprehensive tool to help us better answer the question, “Can we grow that rose here?”

In this industry, we know better than anyone that temperature and precipitation directly impact not only plant growth, but also disease and insect pressure.

In deciding which new roses to offer your customers, we encourage you to try some of your regional 2021 and previous year A.R.T.S. Local Artist winners. With our years of data on these roses growing in your region, we can help you confidently answer the question, “Can we grow that here?” We are proud to serve you as an independent and trusted voice sharing which roses have passed our tests as you navigate through the roses that will not only look good in retail, but be successful for your customers and keep them coming back to you as their trusted source.

To find out more about the A.R.T.S. program and all the winners for your region, please visit www.trustedroses.com

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The novel coronavirus, ensuing uncertainty, quarantines and stay-at-home orders have created a challenging environment for nurseries.

Wholesale nurseries have had to determine whether they are allowed to stay open in the wake of COVID-19. Nurseries that ship cross-country have had to track whether their customers are open, as well. Landscape contractors and retail garden centers in some states have had to fight for “essential” status, a struggle that continues at press time. Keep an eye on our website (nurserymag.com) for the latest updates.

Many nurseries have taken the next step to determine how to abide by the guidelines set forth by the Center for Disease Control. Giving up on spring isn’t an option.

By and large, our nation’s wholesale nurseries are still shipping trees and shrubs even while social distancing. They have constantly evolved their workflow and best practices as guidance from federal, state and local authorities is updated, and in some cases, reinvented their business on the fly. As such, any operational changes or new protocols mentioned in this article are accurate at press time in late April. Depending on when you read this article, they may no longer be in place.

Alan Jones, owner of Manor View Farm in Monkton, Maryland, says his business has stayed open with some changes.

The 100-acre nursery grows a wide range of finished B&B trees and shrubs and propagates a wide selection of potted shrub liners for sale to growers. Jones says the nursery has slightly reduced its office hours by one hour a day. Delivery from its landscape distribution center to job sites is still very heavy, he says, though walk-in traffic has slowed.

“Landscapers in Maryland are considered essential and most are still working,” Jones says. “A few companies have closed voluntarily out of concern for their crew’s health.”

Christa Orum-Keller, chairman and president of Midwest Groundcovers, says her wholesale business is fully operational and ready to serve its customers.

Midwest Groundcovers, based in St. Charles, Illinois, produces more than 20 million plants in one of the broadest collections of species and plant groups of any nursery in the U.S., over 655 acres of production facilities.

Dealing with constantly changing state regulations kept Christopher Uhland, owner of Harmony Hill Nursery in Downingtown, Pennsylvania on his toes. While nurseries and greenhouses were deemed essential and permitted to stay open, in mid-April the governor ordered all independent retail garden centers to close. They were not allowed to have no-contact sales through curbside pickup or delivery, which was a compromise in several other states. When the pandemic started, Uhland had a contingency plan. As it progressed in the beginning, he planned to dig his normal supply of orders, plus a few extras to have on hand when the situation broke. Instead, he had to proceed with extreme caution and dig only on speculation. With landscape customers cancelling or postponing orders because they aren’t permitted to do commercial installations in some cases, he’s finishing up orders, wrapping up his fertilization program and getting into shut down/summer maintenance mode early.

Ariel Montanez, general manager of Pender Nursery in Garner, North Carolina, says the pandemic has yet to slow down production at the nursery, but they have experienced a 5-10% decline in sales compared with this time last year. While that is a workable situation, Montanez says with the ideal weather the area was experiencing before the nation started sheltering in place, he thought the nursery, which sells to landscape contractors, rewholesalers and retail garden centers, could have “easily seen a 25% increase in sales over last year.”

North Creek Nurseries, a wholesale propagation nursery in Landenberg, Pennsylvania, has also experienced about a 5% decrease in sales. Steve Castorani, North Creek's president, says the shifting regulations and closures have affected his customers.

"We anticipate demand when things open up, so we are still producing new product," he says.

Lorne Blackman, owner of Walla Walla Nursery experienced a roller coaster effect in his home state of Washington.

“We were doing OK at first, until our customers started closing,” Blackman says. “A lot of cancellations came in during the first two weeks of April. But at the last minute, business rebounded, and we came in about 80% of last year.”

He expected late April to be a “blowout” in sales for the 40-acre nursery that sells primarily to rewholesalers and independent garden centers. The nursery, which employs 170 people, was awarded funds through the Small Business Administration’s Paycheck Protection Program (see page 14 for more details on relief packages).

John Lewis, owner of JLPN Liners in Salem, Oregon, had shipped out nearly all of his liner material before the virus put a stranglehold on the country. His only cancellations, which represented less than 1% of his sales, were from nurseries in Eastern Canada that couldn’t get their labor from South America.

Extremely wet weather, not COVID-19, caused a dip in sales in April at Wolfe Nursery Direct’s Fort Worth, Texas, rewholesale location. Manager Stacy Estep says although many of her landscape customers jobs cancelled or postponed, they’ve made up for it in new business and many are booked up a month to six weeks in advance. But her customers who do new installations are worried about the future of the housing market, which will also impact her business, she explains.

Loma Vista Nursery in Ottowa, Kansas, is now applying lessons learned from the 2008 economic downturn, says president Lyndsi Oestmann. The nursery “invested thoughtfully in safety and security for our team and in the financial health of the company,” she says.

“As a company, we’re here to help. We’re here be part of the process of ensuring that this industry is as it’s always been: essential,” she says. “Through trusting in what we know, what we’ve experienced and where we’ve been — our industry can apply the best of its key learnings to a future we may not be able to control, but that we can step into with confidence in who we are as professionals and in the valuable services we provide.”

New precautions

Orum-Keller has implemented some changes to Midwest’s protocols in line with the CDC’s precautions. This includes moving as many primarily office and sales employees as possible to working remotely and shifting in-person meetings to video meetings. Midwest has also separated its production work teams, so they are not mixing — in break rooms, bathrooms, etc. By cutting back on intermingling and fraternization in somewhat close quarters, that change aims to reduce or limit the possibility of infection in on-site work forces. Midwest has also been encouraging customers to use the company’s online resources including an increased emphasis on online ordering. Shipping is taking place in the normal fashion, but Midwest has set up hand washing stations on its delivery trucks. The company also is eliminating the need for papers to be signed, which is another way to reduce the spread of the virus through limited contact of commonly touched objects. Orum-Keller also is preparing for an influx of delivery jobs.

“We expect a possibility that when things open up, there will be more requests than usual for delivery of orders,” she says.

The crew at JLPN created four- or five-person squads instead of the normal 15-person teams.

“Now seven or eight teams are taking care of production, but spread out and scattered throughout the nursery,” Lewis says.

At Manor View Farm, account managers and appropriate office staff are working from home. No customers or visitors are allowed in the office and walk-in customer transactions are conducted by phone or through intercom. Jones and his team have asked walk-in customers to call in their orders 24 hours in advance of their pickup, so their orders can be pulled prior to their arrival. Manor View’s yard salesmen are following CDC guidelines and wearing masks. Despite the difficulty, the nursery is making sure there are clear lines of communications with all staff and customers.

“The health and safety of staff and customers is taken seriously,” Jones says. “We have always worked hard to make sure our customers are successful and during these difficult times it is even more important to help customers be successful and safe.”

Production staff at Walla Walla Nursery and North Creek Nurseries are practicing social distancing and wearing masks, and sales staff are working from home. The indoor lunchrooms are closed lunch breaks are staggered.

Effect on the labor pool

Uhland’s nursery is running on a skeleton staff — a result of his workers from Mexico being held up at the border and unable to enter the United States.

“I have not and will not be able to get any of my workforce until everything is cleared in Mexico and the U.S. No one can or will give me any time frame, including my immigration lawyer,” he says.

In the interim, he hired a couple of college students that were home from Penn State.

At Midwest Groundcovers, labor has not been severely impacted. Orum-Keller says that some workers have chosen to take leave due to coronavirus concerns but for the most part, the nursery is fully staffed.

Jones notes that H-2A visa processing seems to be taking priority over H-2B visas. While good news for the nurseries that rely on the H-2A program, the H-2B supplemental visa program is put on hold once its cap is reached. The H-2B cap for the second half of fiscal year 2020 was met on Feb. 18. That included 33,000 visas for worker petitions requesting a start date before Oct. 1, 2020. Jones says many of Manor View Farm’s landscape customers that were capped out after the first lottery do not have their H-2B crews. Those that were successful in the lottery and are able to get consulate interview waivers have started to see H-2B visa crews show up to work.

Sales and production

Manor View Farm did not have a drop in March sales to landscape contractors due to the spring season starting earlier than normal. Jones says April sales will depend on whether landscapers are allowed to continue working. There have been a few orders cancelled and some have been delayed.

Jones also says his crews are not behind in production as the season is ahead of schedule.

“Field digging of deciduous plant material is just about finished,” he says. “We are still planning to start planting once the weather cooperates.”

Orum-Keller expects lower than typical spring sales for the industry as a whole.

“Absolutely,” she says. “We expect garden centers to be most severely impacted negatively but landscapers are operating at a reduced pace — both due to their customers and employees impacted by the coronavirus — but also due to not having their workers fully staffed.”

She says Midwest is not behind in production operations but is behind in sales which has caused the company to pause some of its purchasing and potting. This type of chain reaction will be common among growers.

“We are looking at our current purchase orders for liners and are reducing some of these,” she says. “Our vendors are being flexible, and we are grateful for that.”

She also will likely postpone some potting in the near future, depending on the product and anticipation of demand as the market responds.

JLPN’s Lewis says his sales are down about 5%, but it’s not from the pandemic, but because the tree market is experiencing some oversupply. He estimates there’s a 15-20% overage in the market right now, which may decrease once the nation is on the other side of this crisis. Unlike the days during the Great Recession, he is not hearing about growers slashing prices or competing on price.

Production is going full speed at May Nursery in Havana, Florida, although the effects of the various quarantines have caused a 15% drop in sales during the last three to four weeks compared with the same time last year, reports Richard May, president and general manager.

“We’ll be closely watching the U.S. housing starts reports for the next three or four months,” he says. “If the housing numbers stay steady, we’ll be OK. If it starts a precipitous fall, then we would look to start tightening up on production.”

The supply chain situation

The COVID-19 challenge has ramifications on the supply chain, as well, even impacting the way plants are sold.

At Manor View Farm, Jones’ crew is limiting incoming delivery of plant material for the landscape distribution center to largely material that is already sold. This has created more of a “just in time” inventory system. Jones says the system reduces risk but can increase anxiety for the sales team when incoming deliveries are unexpectedly delayed. He says growers have been very understanding when they realize an entire spring order is not going to be taken in March but spread out over two or three shipments.

“Cash flow is king,” Jones says. “We need to limit the amount of unsold material sitting in the yard at any given time. Our goal is to keep cash flow fluid — if our customers keep paying us, we can keep paying our vendors. We are all in this together and our successful navigation of the current crisis will help determine the success of our customers.”

Montanez says that many of his landscape contractor customers have postponed some jobs, especially the larger companies who make their money on commercial installations. However, the smaller contractors who primarily serve the homeowner market are not only on track but taking on new customers. He expects the landscape trade to ramp back up in the summer, although that depends on the weather.

“If they wait until fall to complete landscape installs, it will cause a backlog. I think a lot of these jobs that have been postponed now will be back online in the summer,” he explains.

Loma Vista’s trucks are delivering product and simultaneously Oestmann and her team are “evaluating everything from staffing models and outdoor growing technologies to innovative software and webinar education and training. [As] a premiere grower for the Midwest marketplace, we’re looking at distribution routes and service channels for creative, cost-effective alternatives that expand on solutions we’ve already put in place.”