As in any business, the ability to specialize paves the way for greater potential sales. Just like doctors can focus their practices in areas like optometry or pediatrics to provide advanced care, plant producers can concentrate in a specific crop (or types of crops) to set themselves apart as experts in the field.

Ed Snodgrass, the fifth-generation president of Emory Knoll Farms in Street, Md., considered this idea heavily as he saw fewer opportunities to become more profitable in his 140-year-old grain crop business.

“I got kind of disillusioned with the American small farm experience from a number of perspectives,” Snodgrass says. “One was economics. There really wasn’t much of a living in it. And that makes a difference.” The other, he says, was ecological. With consumers trending toward organic, he’d have to let his land go fallow for five to seven years while it rid itself of the chemicals he previously used if he wanted to go that route.

“Those were really unacceptable business conditions for me,” he says. “So I thought, ‘Well, I wonder if there’s a way to think about the property in a different way.’”

During a search in the Washington, D.C. area for new crops to grow in the late ’90s, Snodgrass came across a landscape architect who told him he needed plants for green roofs.

When Snodgrass spoke to the landscape architect, he wasn’t exactly sure what a green roof was. He later found that a green roof is an installation of plants on a rooftop that provides stormwater management, has the potential to attract pollinators and other types of biodiversity, and also boasts aesthetic value, especially in urban areas. After conducting more research on its numerous potential benefits to urban areas, as well as his own business, he decided to convert his entire operation to growing ideal plants for green roof installations.

Now, Emory Knoll Farms, also known as “Green Roof Plants,” has provided plant material for more than 1,500 projects (more than 180 acres of rooftop space) all across the U.S. Some of his most notable green roofs include the Library of Congress Audio and Film Archive, Interior of Agriculture, World Wildlife Fund and American Association of Landscape Architects.

Trickle down of benefits

The idea that highly populated cities must continually strive to add greenery back into their ecosystems isn’t a new one.

“Most of the cities in the U.S. were the nicest places to live before we built cities on them,” Snodgrass says. “They were the intersection of the forest and waterways and estuaries.

“Frankly, that’s why people chose them. So when you take all that away, when you put water through pipes and make land into roads and concrete and buildings, you’re dramatically changing how water moves through those areas, and that’s a big problem,” he adds.

When a city is looking to add plants back into area, they can turn to park lands, athletic fields and streets were trees could be planted. The next available spaces are rooftops. After all, cities often contain thousands and thousands of square footage of rooftop space.

Not only can green roofs positively impact water movement throughout a city, Snodgrass says, but they can also change the thermal performance of a building into one with higher efficiency. The plants keep the structure cooler. Additionally, you can create new habitats by providing a place for insects and birds to thrive.

“The green roofs are part of a new trend in horticulture that’s [centered] around biological engineering, and not ornamental horticulture,” Snodgrass says.

Picking the best plants

While creating biodiverse environments on rooftops has plenty of benefits for the building owner and community as a whole, it won’t work without the right plants. Rooftops require varieties primed to last in relatively low-maintenance rooftop conditions.

Mostly, the plant selection depends on the geographic region in which the roof is located. Hardy succulent sedums are a top-tier pick, as they require low fertility and not very much water, Snodgrass says. Some examples include Sedum spurlum, Sedum middendorfflanum and Sedum monatnum ssp. orientale. Other wildlife-type plants including Allium, Echinacea, Rudbeckia and Phlox can also work well, according to greenroofs.com, an industry platform for all topics related to living roofs. Even some drought-tolerant grasses, like Andropogon or Panicum, can also thrive on rooftops, the site reports.

The conditions on a rooftop are harsh, Snodgrass says. So green roofs need to be able to withstand all of the direct sunlight and lack of care the plants will receive in a gravel-based media about 3 or 4 inches deep.

In order to plant for greater success, Snodgrass recommends a successional approach. “They’re not really like a garden design where you say, ‘I’m going to put in a perennial border. Then I’m going to have someone maintain the integrity of that design,” he says. Instead, it’s OK if one group of plants is performing better at the time of installation, and another group of plants becomes more dominant after time passes.

But, when wind erosion or noxious weeds roll in, you’ll need to find a plan for replanting. Or, depending on the specific roof’s criteria (Say, the expectation is that the roof must be 85-percent vegetative in two years), some or all of it may need to be replanted. However, in most cases, even if a small area of plants dies off for one reason or another, the rooftop can still handle the stormwater because most of the work is being done by the media. It will still be functional. “If you go out in the desert, the plants aren’t right up against one another,” Snodgrass says. “But the desert is a stable ecosystem.”

However, he notes that in the U.S., we care a little bit more about a green roof’s appearance than those in Europe or other areas of the world. There, the function of the green roof outweighs aesthetic value.

Another benefit of the green roof is the lack of pest pressure. “There’s not a lot of harmful insect life up there,” Snodgrass says. “Things like aphids won’t be up there because there’s too much wind.” Plus, because of the access to direct sunlight and wind, the chance of constant humidity and dampness also decreases on a rooftop.

Customize, don’t add on

Snodgrass says that although green roof plants are relatively easy to grow, annual or perennial growers should take caution when deciding to take on these varieties in their operations.

“Most commercial nurseries push product pretty hard with water and fertility, so the tissue is a little soft for a green roof,” he says. He says that the plants need to be hardened off before they’re sent to the client in order to be suitable for an environment of neglect. “You don’t want that call that says, ‘Hey, all these plants you supplied us, they’re mostly dead,’” he says, adding that while they could be the correct genus and species, they still have to be grown the right way.

If you’re a green roof plants producer, the general sales process is also totally different. Snodgrass says the orders of green roof plants have taken anywhere from one day to six years to complete. Adjusting to the new sales process can be a challenge for a grower who’s accustomed to a steady spring or fall retail schedule. If growers are to produce green roof plants, they’ll also need to be ready to take on some additional responsibilities as it relates to sales. Snodgrass’ job requires him to wear many hats — and most of the time, it is “Consultant.”

He says that as a green roof specialist, he spends a lot more time on the phone with customers compared to wholesale nursery growers. “It’s not an order-fulfillment world,” Snodgrass says. Customers are usually installers, designers and maintenance staff who don’t necessarily have a plant background. “It’s emerging technology, so there’s a lot of handholding horticulturally,” he says. Snodgrass finds himself teaching roofers and architects about which plants will work well based on criteria like sun and shade of the building, and examining more subjective aspects like, Is the company CEO’s window overlooking the roof?

The final destination

Once plants are ready to ship, the sales transaction doesn’t end there. There’s even more planning to make sure product is delivered at the right time, in the right condition for installation.

There’s considerable checking and re-checking on all the moving parts of green roof plants delivery, including construction delays — or acquiring proper ID if you’re working on a federally secure facility, for example.

Packaging that plants are shipped in must also be different, Snodgrass says, because the plants will likely be lifted with a crane, possibly 30 to 40 stories high. Growers will want to ensure plants can be secured to lower the risk of them falling off of the lift.

Timing of the delivery is also key, because crane time can cost hundreds of dollars an hour, he adds, in addition to the highly skilled labor that’s being paid by the hour for the job.

In case anything goes wrong on a green roof project, “You can’t have your customer bleed cash like that,” he says. “So, we have to have delivery mechanisms that fit with the construction world, and not the landscape world.”

Picking the best people

Learning this new market for the past 15-plus years has been exciting for Snodgrass, but perhaps one of the most rewarding aspects is the interest he’s garnered from his employees. Though Emory Knolls’ staff is small, Snodgrass says he’s never had trouble acquiring labor for his work in the green roofs market.

“You get people who are enthusiastic about where your plants end up, so it’s not [as much] of a grind,” he says. He currently employs an intern from the University of Melbourne in Australia working toward an urban horticulture degree, as well as two other young employees who, at press time, were studying abroad to increase their horticultural knowledge base.

“I would trust them with anything. I mean, they’re just great,” he says. “They innovate, and you get more than just compliance. You get the next level of service out of them.”

Snodgrass says he recently spent two months in Australia and China, and he couldn’t have left the business in their hands unless they were truly capable.

A worldwide impact

Snodgrass’ travels are geared toward helping to teach others about how to build green roofs. He also consults for a Chinese green roof company that’s looking into how to implement green roofs in different regions of China as the country makes more effort to become environmentally sustainable. Snodgrass has taught the staff how to propagate, and he’s also met with local officials to move public policy forward to make green roof installations smoother. He’s done similar work for regions in Australia and New Zealand.

Snodgrass has also co-written three books on the topic: one about which plants to use for green roofs, another about green roofs and public policy, and one about how to construct smaller, DIY green roofs. His publications can be found at amzn.to/2bi9zJK

The possibilities abound for Emory Knolls Farm and Green Roof Plants. The 140-year-old business that had hit the proverbial wall has now become a hub of innovation, supplying cities in North America and around the world with a new way to view horticulture and its potential roles in our modern world.

Calcium (Ca) is an important element for plant growth, and plays a number of critical roles in the plant cell and in cell membranes. It is considered to be a secondary macronutrient. Calcium is important for its various structural roles in plant growth, increasing cell wall strength. It is also involved with cell elongation, as well as cell division. Cell wall thickness and strength are increased with increased Ca levels.

Calcium is also an element that influences the cell pH and acts as a regulatory ion in carbohydrate translocation. It has been shown to increase a plant’s resistance to disease, salinity tolerance, and drought protection.

If calcium is deficient in the media, there will be cell wall stability problems. Calcium levels will vary by species and even cultivars in greenhouse crops, but typically are between 0.5 to 3 percent dry-weight of shoots in most plants.

A look at growing media

Typically, most growing media contain calcitic and dolomitic limestone, and frequently gypsum (CaSO4). In most cases these media-incorporated materials will provide sufficient calcium for the crop cycle. Calcium from limestone is typically about 70-percent Ca. Gypsum will dissociate in the soil solution into Ca2+, and SO4 -. The rate of gypsum dissolving into the media solution will depend on particle size of the gypsum, with small particles dissolving more rapidly than large particles. The calcium (Ca2+) will become attached to the surfaces of media particles after incorporation and blending, and is held on the media particles by the negative electrical charge on those particle surfaces. As plant roots give off H+ ions to the media, calcium and other cation species are exchanged from the media particle to the soil solution, and subsequently to the root surfaces.

Unlike some of the other ionic species taken into the plant, calcium is taken up with the transpirational stream when the plant is experiencing a high transpirational rate. Plants that are not transpiring at a high rate will not be taking up large amounts of Ca. Once Ca2+ is in the plant, it will be translocated upward through the xylem and becomes a constituent of the plant cell wall tissue, or is deposited in the cell vacuoles.

Symptoms of low calcium levels

The plant’s calcium level depends on the growing media calcium supply. Deficiency symptoms include roots browning, short stubby axillary roots, and shoot injury showing necrotic (brown) areas, distortion and stunting.

Plants with calcium deficiency are smaller than normal, with dark green lower foliage, as well as flower bud abortion or reduced flower size. If a plant has damaged root tips, the deficiency symptoms can occur even if the media calcium level is adequate, as the plant’s root tips take up this element. Blossom end rot (a well-known Ca deficiency symptom) on tomato and tip burn of lettuce are a result of low Ca and possible moisture stress.

Adjusting Ca in growing media

As peat moss is typically at a pH of 3 to 5, limestone can be incorporated to raise the pH. If the media contains coir, the starting pH of the media will be higher than one based predominantly on peat. Coir usually is at a pH of 5.5 to 6 and, after blending, would require less limestone to adjust the media pH level.

If the water source used for irrigation contains high levels of calcium, then it would then be advisable to use fertilizer with low or no calcium, such as a 20-10-20 formula. Target ratios for fertilizing should be potassium (K) to Ca to magnesium (Mg) 4:2:1.

Coir typically contains more potassium and magnesium than peat, but equal or less Ca. K+, sodium (NA+), NH4+, and Mg2+ can be antagonists in Ca2+ uptake, so it is important to keep these elements at appropriate levels. Therefore, if the level of an antagonist such as K+ is too high in the media solution, Ca+ may not be taken up at the appropriate rate.

Calcium nitrate (CaNO3) or potassium nitrate (KNO3) combinations can be used in a fertility program to reduce micronutrient toxicity caused by using the peat-lite fertilizers (such as 15-16-17, 20-10-20), as these peat-lite formulas have higher levels of micronutrients than some others, and an abundance of nitrate (NO3-) in their formulas. These peat lite formulas can raise iron (Fe) and manganese (Mn) to toxic levels in low pH conditions, so careful monitoring of media pH is critical.

Nutritional best practices

It is advisable to check pH and EC on a regular basis, and with bedding plants, this should be done weekly. A useful tool is the pH/EC combination meter, and there are a number of options available available. Often the pH electrode has a limited lifespan, so growers should get a tool that has a replaceable pH electrode. If the unit is properly cared for, including using an electrode storage solution, the maximum life of the instrument will be obtained. The cost of a replacement electrode is much less than replacing the pH meter, and the lifespan of the pH electrode should be from two to many years with proper care.

Plant tissue testing and media tests are tools that should also be regularly utilized by growers. Crops that have a short growing cycle may only need a tissue test one time, but plants that are growing on a longer cycle may need to be tested several times during the growth period. Many lab options are available to a grower, but choosing a lab is not a random decision. Select your lab based on their quality of testing and service. Stick with the same lab for tissue and media tests, as labs differ in their testing procedures. Switching between labs can only create confusion as to the results of the tests.

Managing calcium in your production situation is not only important for optimum plant growth, but to yield a greater understanding of the nutritional management of the crop as well. Many growers keep very good records and routinely test media and plant tissue for nutrient status. Good record keeping of the testing results and environmental conditions the plants were grown under will provide the best information for future crops.

Sinclair is an extension educator at Penn State University specializing in floriculture, propagation, breeding and nutrition.

At stores like Costco, Walgreens and Kroger’s nationwide, Bloomaker’s tulip, hyacinth, daffodil and amaryllis arrangements are often on display near the entrance. At first glance, they may look like other container or bouquet arrangements, but if you examine them more closely, down to the very bottom of the stem, you’ll see that these “cut flower” products aren’t really cut at all. Instead, the popular varieties are still attached to their roots, which are gathered tightly together (along with their bulbs) at the base of the company’s patented tall, clear glass vase.

These beautifully blooming varieties are available as single bulbs, or in arrangements ranging from three bulbs to 11 bulbs.

All of the flowers, which are also patented by the Virginia-based operation, are grown hydroponically. This means that they’re produced without soil. While leafy greens like lettuce and kale grown in produce operations may be the more commonly referenced hydroponic varieties, Bloomaker also uses water as the media for its ornamental varieties. Water is distributed to plants placed in crates on a floor during the growing period. The water is controlled for nutrients and pH, and is constantly monitored to ensure there’s enough for the crop to thrive.

Growing and consumer perks

Bloomaker’s flowers tend to stay fresh longer than traditional cut varieties, says Head Grower Jelte Tjalf Schaap. “When you have cut flowers, they’re already blooming,” he adds. “Within a couple of days they already start to wilt, but [because] we keep the bulbs on the plants, they actually last for weeks.”

In Tjalf Schaap’s opinion, colors also appear to be more vibrant. He attributes this to the plants’ constant access to water.

In addition to the aesthetic benefits of their crops, Bloomaker’s varieties have growing and production advantages. Firstly, the overall growing season is a few days sooner. And although it may not make a huge difference, the extra bit of time adds up when you’re pushing out more than 17 million bulbs a year, Tjalf Schaap says.

Additionally, no soil means no mess, and by not using a traditional growing mix, Bloomaker’s varieties have reduced risk for pests transporting from one plant to another. It also makes the labor “more comfortable,” Tjalf Schaap says, because lifting and transporting isn’t nearly as heavy.

Adjusting nutrients for the crops also isn’t nearly as difficult as with a soil-based medium, according to Tjalf Schaap.

“With tulips, you don’t see that the crop requires really specific nutrients because there’s already a lot of nutrients inside the bulb from the previous growing year,” he says. “All the micronutrients, like iron and magnesium … [are] not that important because they’re already in the bulbs.”

The bulbs are packed in the vase design, which holds them in place and also keeps the water underneath where the roots are. The design is nearly spillproof. “To get the water out, you have to hold it almost upside down,” Tjalf Schaap says.

Attached to the vase is a colorful label with basic care instructions. It also directs consumers to Bloomaker’s mobile-optimized website that provides more detailed care and aftercare tips.

And because consumers can take the bulbs of the plant home with them, they can use them to grow the flowers again during the following seasons — another added value.

Depending on where the consumer is located (i.e., where cold-weather winters are present), they may use those bulbs year after year.

“It depends on the climate, but in general, you can plant them in your garden about 4 inches deep and then every year, you have flowers,” Tjalf Schaap says.

The new Topspin begonia from Syngenta Flowers is a green leaf series ideal for early spring through summer production. Increased plant vigor and cold tolerance allows the flexibility of growing Topspin at lower finished temperatures, providing cost savings and greenhouse efficiency. Topspin begonias are well-matched for early flowering and uniformity across the series. They are available in four colors (Scarlet, White, Pink and Rose) as well as a mix. Featuring outstanding field performance in a wide range of climates, Topspin begonias also thrive in the garden with strong vigor, large flower size and well-branched habits.

For more, syngentaflowers.com