January 2015 – My Chicago Botanic Garden

Top Gardening Trends for 2015

The start of a new year prompted us to ask experts here at the Chicago Botanic Garden what they expect to see in 2015. Their predictions might help you anticipate problems, promote pollinators, and add interest to your own patch of green.

What’s likely to trend? Rainwater management, cumulative stress problems, corresponding color schemes, new compact hybrids, and heightened concern for butterflies, birds, and bees.

“Two fundamental issues will drive gardening trends in 2015—erratic weather patterns and a growing concern for the environment,” said Tom Tiddens, supervisor of plant health care. Additionally, gardeners will move away from contrasting color schemes and increase their use of outdoor spaces for entertaining and relaxing. Here’s a closer at what our experts anticipate for the coming season:

Cumulative Stress

Several years of erratic weather—drought followed by prolonged, record-breaking cold—have had a cumulative stress effect on many plants, especially evergreens. “I think we will be seeing more stress-related problems in 2015,” Tiddens said. Stress causes a lack of plant vigor, increasing plants’ susceptibility to pests and diseases.

PHOTO: Brown marmorated stink bug. — Be on the lookout for brown marmorated stink bug ( *Halyomorpha halys* ). Photo by David R. Lance, USDA APHIS PPQ

Give your plants extra TLC and be on the lookout for viburnum leaf beetle, expected to hit the Chicago region soon. Other high-consequence plant pests and pathogens to watch for include brown marmorated stink bug, lantern fly, and thousand cankers disease. Emerald ash borer and Asian longhorn beetle remain threats.

Rainwater Management

More home gardeners will take steps to either improve or prevent the lake that seems to form in their yard every time it rains, said Heather Sherwood, senior horticulturist. Rain barrels and rain gardens will be two increasingly popular solutions. Rain gardens temporarily hold rainwater and rely on specialized native plants to wick water into the soil. Rain gardens offer many environmental benefits, soaking up 30 percent more water than a typical lawn, and minimizing the pollutants that flow into storm drains. The native plants used in rain gardens provide habitat for birds, bees, and beneficial insects. To learn more, go to: chicagobotanic.org/conservation/rain_garden or chicagobotanic.org/library/spotlight/raingardens.

Corresponding Color Schemes

PHOTO: Dahlia 'Gitt's Crazy'. — Monochromatic color schemes are in! Experiment with the 2015 Pantone Color of the Year: “Marsala.” (Shown: *Dahlia* ‘Gitt’s Crazy’)

Gardeners will move toward more monochromatic displays, such as using shades of oranges alone, or shades of purples and blues together in the same design, according to Tim Pollak, outdoor floriculturist. Increased use of leaf interest will provide texture and shades of green. Sherwood sees red: from the earliest tulips to azaleas, dahlias, Japanese maples, large maples in the fall, and lastly, the red twigs of dogwood for seasonal interest.

Pollak also predicts home gardeners will use their outdoor spaces more and more for relaxing and entertaining, increasing the demand for outdoor décor. The Antiques, Garden & Design Show, April 17–19, 2015, will offer ideas and one-of-a-kind garden elements.

Less Is More

Jacob Burns, curator of herbaceous perennials, is excited to see new compact hybrids to make their way into the U.S. market next year, and expects them to catch on with home gardeners. New breeding efforts have produced dwarf versions of Japanese anemones (Anemone x hybrida) that are perfect for containers, or the front of the border. Rare among these fall-blooming windflowers is Anemone ‘Wild Swan’, which produces white blooms with a beautiful blue backing. Burns also welcomes new compact cultivars of little bluestem (Schizachyrium scoparium) available in 2015. ‘Cinnamon Girl’ reaches a height of just 28 inches, and transitions to red-purple foliage by late summer. Also on his list are cultivars ‘Twilight Zone’ and ‘Smoke Signal’.

Birds, Bees, and Butterflies

PHOTO: A honeybee from the Fruit & Vegetable Garden hives pollinates some Echinacea purpurea — A honeybee from the Fruit & Vegetable Garden hives pollinates some *Echinacea purpurea*.

The increased availability of equipment and support—both online, and at better garden centers and the Chicago Botanic Garden—will help boost the number of backyard beekeepers, said Lisa Hilgenberg, horticulturist, Regenstein Fruit & Vegetable Garden. Hand in hand with the hives will be the continued rise of bird- and pollinator-friendly gardens filled with nectar-rich and native host plants. Pollak predicts a continued upward trend in demand for organic, pesticide-free and non-GMO (genetically modified organisms) plants and products. Gardeners looking for more information may be interested in attending a Beginning Beekeeping Workshop on February 7, 2015.

Vanilla inhabitants: The search for associated bacteria and fungi

For this year’s Orchid Show, we’ve gathered stories about the most famous orchid of them all: the genus Vanilla. (Yes, vanilla is an orchid.) One unusual story comes from Ph.D. student Lynnaun Johnson, whose work in our doctoral program in Plant Biology and Conservation took him to Mexico, the native land of edible vanilla.

Last April, I ventured to Mexico as part of an international team investigating how cultivation practices influence the growth and health of the orchid Vanilla planifolia.

Vanilla planifolia produces the seedpods used to make vanilla, the spice used for flavoring desserts and beverages, and for providing wonderful aromas in candles, perfumes, and many other things. This collection trip would take me to vanilla’s native habitat of Mexico. All varieties of vanilla originated in Mexico, including those of Madagascar and Tahiti.

Vanilla cultivation

Tahitian vanilla is a hybrid of V. planifolia (shown) and V. odorata. Photo by H. Zell CC-BY-SA-3.0

While in Mexico, I visited three farms in the state of Veracruz and one in the state of Puebla. It was fascinating driving to these vanilla farms with my Mexican collaborators. It took us three days of traveling to complete our field collections. Each of the four farms had very different methods of growing V. planifolia. For instance, one of the farmers said he knew what his plants needed and thought growing his vanilla on concrete blocks was the best method. At another farm, the farmer brought decaying wood from a neighboring forest and used it as mulch for his vanilla plants that grew on living posts known as “tuteurs.” This was different from the other farmers who grew their vanilla on trees in the forest and wooden dead “tuteurs.”

Each of the plantations had different soil texture. At the last organic farm, the soil was compact and hard. At the farms that were in the forest, the soil appeared rich and softer. There is no way to quantify the terrestrial root growth, but I did note that the roots in the organic farms were longer and healthier, with some growing up to 4 or 5 feet when we dug the roots up from the soil.

PHOTO: A view of the Pantapec vanilla farm. — At the Pantapec farm in the state of Puebla, Mexico, vanilla is cultivated in a highly managed environment.

PHOTO: A view of the 1 de Mayo vanilla farm — By contrast, the vanilla grown at 1 de Mayo farm in the state of Veracruz, Mexico, is cultivated in a completely natural environment.

The benefits of fungi

Research on rare and endangered orchids usually focuses on finding fungi to help in the germination of orchids. We know that orchids will only germinate in nature using fungi. In addition, fungi living inside of plant leaves can benefit the plants’ health by preventing pathogens from growing. Also, bacteria living within the plants and fungi can be beneficial in the same way as the endophytic fungi. (Photo: V. planifolia tissue microscopy at 100x)

My part of the research project is to collect root samples from V. planifolia from each of these different farms to study the fungi and bacteria inhabiting this orchid. Currently, not much is known about the microbes (fungi and bacteria) that reside in orchid roots. Some fungi and bacteria can cause diseases. For example, with the appearance of a fungal pathogen such as Fusarium oxysporum, Mexican farmers can lose 67 percent of their crops when the Fusarium causes the rotting of the Vanilla’s stem and roots. On the other hand, there are beneficial fungi that inhabit roots, known as mycorrhizal fungi. These beneficial symbiotic fungi acquire mineral nutrients for the Vanilla, and sometimes receive carbon from the orchid in exchange. Although 90 percent of plant species have mycorrhizal fungi, and while we have a good understanding of mycorrhizal fungi of some of these relationships, relatively little is known about the mycorrhizal fungi of orchids, including V. planifolia. The reason for this is that isolating and growing the fungi and bacteria associated with orchid roots can be difficult, and some have never been grown outside of their host.

At each farm, I wanted to sample five individual plants of V. planifolia. Additionally, because of the lifestyle of this orchid, I also wanted to sample the above-ground roots (epiphytic) and the below-ground (terrestrial) roots in the soil. Using either a scissors or a scalpel, I cut small root samples and placed them into Ziploc bags. The vanilla plants are very precious to the farmers, and so a few were initially uncomfortable with our cutting off pieces, but ultimately they were very accommodating.

Epiphytic or terrestrial?

Typically, vanilla grows as a vine, with two types of roots: epiphytic roots (those that wrap around trees or other structures) and terrestrial (soil) roots. This is referred to as hemiepiphytic, because it starts in the ground and grows upward onto the tree’s bark. Many research papers suggest that epiphytic roots do not harbor many fungi, because these roots can photosynthesize, and do not need mutualistic fungus partners.

Back here at the Chicago Botanic Garden, I am in the process of evaluating the microbial community that lives in the root samples I collected. We are using a new technique called high-throughput sequencing that will enable me to evaluate the entire fungal and bacterial community within the orchid’s roots by using their DNA as a way to fingerprint the individual species of microbes. We are not certain how many species of fungi and bacteria we will find, but we predict that this method will give us a good picture of the fungal and bacterial community in these roots and if these communities differ among the different farming techniques. These data will be used to better understand how epiphytic orchids utilize mycorrhizal fungi and refine the best conditions to grow vanilla and prevent diseases in the plants.

This research trip was a delight, not only because of the samples that I collected, but also because I could learn more about how vanilla is grown and used. The farmers showed us how they cure and prepare the vanilla by fermenting it in the sun and before drying it thoroughly. I also tasted homemade “vanilla moonshine,” generously offered by the farmer’s wife. When visiting Papantla, I learned about the Aztec myth that explained how forbidden love created the sacred vanilla orchid. And of course, I was elated because I usually spend the majority of my research time in the lab. And here I was in the tropics, after spending the previous months facing the bitter Chicago 2014 winter.

Winter Infographic

Think plants look brown and dead in winter? There’s plenty of life still going on beneath the surface!

A Scientist with Orchid Fever

With our Orchid Show set to open on mid-February and the first shipment of flowers due to arrive any day, we all have a touch of orchid fever here at the Chicago Botanic Garden.

Naturally, we wondered who among us might have the worst case (or best, depending on how you look at it). So we sent out a simple query: do you grow orchids at home? Here follows the best answer ever, from Jim Ault, Ph.D. (He’s our director of ornamental plant research and manager of the Chicagoland Grows plant introduction program.)

PHOTO: Orchids in kitchen window at Ault house. — A view of the kitchen window at the Ault house.

Yes, I do indeed grow orchids at home. I haven’t counted them recently, but I’d admit to 50-plus plants.

I simply find orchids to be fascinating for their seemingly infinite variations of flower sizes, shapes, colors, fragrance (very important to me!), and for their diverse ecological adaptations (epiphytes, terrestrials, lithophytes) and the resulting puzzle of how best to cultivate them. I first got interested in orchids in the 1970s, both from seeing some in the greenhouses at the University of Michigan, and also from visiting my grandmother in Miami. She was very active in the Florida fern society of the time, and had a backyard of ferns she grew from spores, with a smaller collection of orchids. She would send me home with plants on every visit, all of which I eventually lost, as I didn’t really have a clue as to how to grow them! But I was hooked, I think safe to say now, for life.

PHOTO: Rhynchostylis gigantea. — *Rhynchostylis gigantea*

As a graduate student in the 1980s, I had a fairly extensive collection of orchids, and was in fact breeding them and germinating their seed in tissue culture; my first breeding projects ever. This hobby actually led me to my career as a plant breeder (of perennial plants) today. I was a member of the Baton Rouge Orchid Society for five or six years, attended quite a few orchid shows and meetings, gave lectures on orchids, and had the chance to visit some of the venerable orchid businesses like Stewart Orchids in California, Fennell’s Orchid Jungle, and Jones and Scully in Florida at perhaps their peak heydays. But my orchid collection had to be abandoned in the late ’80s when I moved to Pennsylvania. Most were sold to a nursery in North Carolina, and some were donated to Longwood Gardens, where I worked from 1988 to 1995.

My orchid hobby came and went multiple times over the intervening years (decades), mostly from a lack of appropriate space to grow them, time, etc. But starting about three years ago, I began seriously accumulating plants again. There was a bit of a learning curve, as many of the hybrids I knew were no longer available; there has been an explosion of breeding new orchid hybrids, many of which were unknown to me; and also orchid names are changing rapidly due to modern DNA technology being used to revise their nomenclature. Just figuring out where to buy plants was an adventure, as most of the orchid nurseries I knew were long gone.

PHOTO: Slc. Little Toshie 'Gold Country' (upper) and Sc. Seagull's Beaulu Queen (lower). — *Slc.* Little Toshie ‘Gold Country’ (upper) and *Sc.* Seagull’s Beaulu Queen (lower)

Currently I grow mostly Cattleya alliance species and hybrids, with an emphasis on the “mini-catts” or miniature Cattleyas, and also a smattering of the larger Cattleyas. Among my favorites of this group are Cattleya walkeriana selections with their heady mix of cinnamon and citrus fragrance (to my nose) and their hybrids like Cattleya Mini Purple; various species formerly in the genus Laelia such as Laelia pumila, (= Cattleya pumila), Laelia dayana (= Cattleya bicalhoi), Laelia sincorana (= Cattleya sincorana), and other closely related jewels of the orchid world.

I’m excited to have in bloom right now the diminutive Sophronitis coccinea (= Cattleya coccinea) with oversized, 2-inch wide flowers of an intense orange-red on a plant no larger than 3 inches tall. S. coccinea is a challenge to grow at all, let alone grow well, but its hybrids are much easier to cultivate, and strut their stuff with flamboyant flowers in deep red, orange, purple, and violet, often produced two and even three times a year.

I also grow a modest number of other species and their hybrids, mostly Neofinetia falcata, Rhynchostylis gigantea, and related hybrids.

PHOTO: Laelia pumila 'Hawaii' — *Laelia pumila* ‘Hawaii’

I grow most of my orchids in bark mixes, some in New Zealand sphagnum. I use both plastic and clay pots as well as plastic or wood baskets. I prefer the latter as the plants respond best to the excellent aeration around their roots that the open wood baskets provide. Unfortunately this also poses a challenge, figuring out how to hang baskets close enough to windows to provide the necessary high light needed, as well as providing sufficient humidity in the dry winter months.

My plants spend the summer outdoors on a nursery bench under a piece of shade cloth, and overwinter indoors under lights in the basement, and in nearly every south-facing window in the house! My family is to be commended for their suffering—and patience—after finding sinks and bathtubs filled with plants freshly watered, or obstructed views out windows crowded with plants. Such is life with an orchid addict.

The Orchid Show opens mid-February—a lovely way to celebrate Valentine’s Day. Order your tickets now!

Between a Rock and a Future

A pretty little iris growing in the mountainous rocky outcrops of Jerusalem is the focus of a research collaboration stretching over 6,000 miles.

Scientists at the Chicago Botanic Garden and Jerusalem Botanical Gardens have combined their strengths to study the natural population structure, or remaining genetic diversity, of the rare Iris vartanii. What they have discovered may save the species, and others like it, into the future.

The finicky wildflower exists in just 66 locations in Israel’s Mediterranean ecosystem—a dangerously low number. New road construction, urban expansion, and even afforestation in the area have reduced the availability of its natural habitat, fueling the crisis. For a plant that is endemic to, or only lives in, one narrow region, that spells trouble.

PHOTO: Iris vartanii ©Dr. Ori Fragman-Sapir — *Iris vartanii* Photo ©Dr. Ori Fragman-Sapir

“Whenever you have a rare plant, you always have concern that as diversity starts to go down, the plant becomes more and more endangered,” explained Garden volunteer and molecular biologist Eileen Sirkin, Ph.D. “The idea of diversity is that maybe one plant is more drought tolerant, another is more flood tolerant, and another is more wind tolerant, for example, so no matter what the conditions, there will be some survivors. As you narrow that, you are more and more in danger of losing that species.”

Do the existing plants contain adequate genetic diversity? And to sustain the species, how many plants are enough? These are the central questions.

Gaining a Foothold

The scientific partnership between the two gardens was forged when Jerusalem Botanical Gardens’ Head Scientist Ori Fragman-Sapir, Ph.D., who has monitored the species and studied its demography in the field, visited the Chicago Botanic Garden and met with Chief Scientist Greg Mueller, Ph.D. The two quickly saw an opportunity to combine Dr. Fragman-Sapir’s research with the genetic capabilities of the Garden to answer those critical questions.

“Conservation genetics is one of the core strengths of our science program,” said Dr. Mueller. “There are few other botanical institutions that have this expertise, especially internationally, so we are happy to collaborate on interesting and important plant conservation projects like this one.”

“Conservation genetics is one of the core strengths of our science program,” said Dr. Mueller. “There are few other botanical institutions that have this expertise, especially internationally, so we are happy to collaborate on interesting and important plant conservation projects like this one.”

It wasn’t long before Fragman-Sapir began shipping leaf samples to the Garden’s molecular ecologist, Jeremie Fant, Ph.D. Together with his dedicated volunteer Dr. Sirkin, Dr. Fant set to work extracting data from the samples and documenting DNA fingerprints for each plant. Once they had a large enough data set, they compared and contrasted the findings—looking for similarities and differences among the plants’ genetic compositions.

Gaining Altitude

To give scientists a point of comparison, Fragman-Sapir shared tissue samples from five populations (geographically separated clusters of plants) of a more commonly occurring related species, Iris histrio. By also documenting the DNA fingerprints of those plants, which grow in the surrounding area, but unlike Iris vartanii are not rare, Fant was able to determine how much diversity is needed to sustain the species.

PHOTO: Volunteer Dr. Eileen Sirkin — Dr. Eileen Sirkin volunteers in the laboratory.

Although the study subject is far away from the Garden, its challenges hit close to home. In 2013, Fant and Sirkin published findings from a similar study on a rare plant found at Illinois State Beach Park, Cirsium pitcheri. For that initiative, they examined the DNA of plants from a restored site at the beach and compared them to the DNA of naturally occurring plants across the range, measuring diversity.

“We’re always working with rare and endangered species, and we collaborate with different people around the world to answer those questions,” explained Sirkin.

The Summit

After completing a statistical analysis of Iris vartanii’s DNA fingerprints, Fant made several encouraging conclusions but also issued an alert for continued attention.

The rare species’ genetic diversity was similar to that of Iris histrio. “This does tell us that genetic diversity in Iris vartanii is not likely an issue,” said Fant, who was not surprised by the conclusion. “Genetic diversity of any population is determined by the origins of the species, the age of the population, and proximity to the site of origin,” he explained. “As both species likely arose locally [from Jerusalem northward to the Galilee and further on] and have been around for a very long time, they possess similar levels of genetic diversity.”

PHOTO: Dr. Jeremie Fant. — Conservation scientist Dr. Jeremie Fant

Especially encouraging was that each Iris vartanii population had significant differences in their genes, likely a result of their longtime separation. The findings highlight that it is all the more valuable to conserve each population for their potential to contribute unique genes to future plants, according to Fant.

Although many populations showed high diversity and low inbreeding, which is preferred, others showed the reverse, increasing their potential risk of extinction. The latter group, explained Fant, may benefit from extra special monitoring and care.

To conserve the existing populations, attention will need to be given to their surrounding natural areas, explained Sirkin. “If you find a species that people like and you study it and say we need to do all these things to save it, you are not just saving one plant, you are saving an ecosystem, including all the other plants, insects, other invertebrates, lizards, birds, and whatever else is involved in that ecosystem,” she said.

The findings and recommendations give land managers a clear direction for their conservation efforts, all because of one eye-catching plant that told the story of many.