For the Love of Plants

For May 1, 2019

Are you searching for a good climber to add beauty to a bare wall or fence?  Gelsemium sempervirens ‘Margarita’ (Carolina Jasmine) is a fine-textured, evergreen, perennial vine and a PHS Gold Medal winner. The twining growth habit and fragrant yellow trumpet-shape flowers of this native are equivalent to an Olympic score of ten. ‘Margarita’ will scramble up or cascade over obstacles, creating a splash of color wherever it grows and reaching heights of 10 to 20 feet.

The Gold Medal program honors and promotes woody plants of outstanding merit. Nominations for Gold Medal Plants are submitted to the Pennsylvania Horticultural Society by home gardeners, garden designers, horticulturists, landscape architects, nursery owners and propagators. The plants are chosen for their superb eye-appeal and evaluated for their performance and hardiness in the growing region of Zones 5-7. Gold Medal winners exhibit standards of excellence for pest and disease resistance, as well as ease of growing. They are also chosen for their year-round beauty, whether it be foliage, flower, form or bark.

“This plant exemplifies all the best characteristics of a Gold Medal winner,” says Steve Mostardi, Chair of the PHS Gold Medal Plant Selection Committee. “It’s a carefree native that grows in sun or shade, and one of the few vines that keeps its foliage all winter.”

In peak bloom now, Steve recommends getting this plant in the ground anytime through mid-summer.  ‘Margarita’ is readily available at nurseries throughout the area.


Posted on April 3, 2019

Spring is officially here, but not all your bulbs and trees will blossom for a few more weeks. Give your landscape a jumpstart by planting a true harbinger of spring, the Prunus mume, also known as Japanese apricot or Chinese plum.

A native to Korea and China, this rare, deciduous tree has been in cultivation for over 1,500 years. Reaching 20 to 40 feet in height, Prunus mume will summer with green leaves. In mid to late winter, depending on the zone, cultivar and weather, colorful blooms in red, pink or white, both single or double, will open over several weeks.

This tree isn’t well known in the United States even though it has long been a favorite in Japan, where there are an estimated 300 named cultivars. One of the largest collections of Prunus mume is found in Raleigh, North Carolina, at the J.C. Raulston Arboretum at North Carolina State University, where Dr. J. C. Raulston worked to showcase the tree for years.  Locally, The Scott Arboretum of Swarthmore College has a lovely collection as well.

“These trees are elegant in their stature and floral display, unlike some of the larger, bold cherry varieties,” says Sam Keitch, Public Landscapes Project Manager at PHS.  “They are not commonly sold in nurseries and are a novelty to come across.  If you’re lucky enough to find a small one, it’s worth the investment.” Locally, Brandywine Trees, LLC, in Chester County, Pennsylvania, sells an assortment of them. Another resource is the Forestfarm catalog.

The Public Landscapes team is looking for unique candidates for some of its smaller spaces in the city and this is one of the species selected.  “We are working to curate and increase the diversity of our older, historic sites. It’s a perfect tree to announce spring in our intimate, urban spaces, and we plan on placing then in several locations throughout the city,” says Sam. “Our strategy is to complement the blossoms with a potpourri of bulbs for a staggered bloom sequence,” he adds.  

Several to choose from include ‘Peggy Clarke,’ with pink double flowers; ‘Bonita,’ a rose-red semi-double blossom; ‘Dawn,’ a large, ruffled double pink blossom; ‘Fragrant Snow,’ a beautiful, white semi-double flower; or ‘Kobai’ with pinkish-red flowers.


Posted on February 27, 2019

The PHS Gold Medal Plant program helps gardeners of all levels by spotlighting and promoting woody plants of outstanding merit. Since 1979, PHS experts have chosen plants for their exceptional beauty, performance, and hardiness in the growing region of Zones 5 – 7.

“The Gold Medal Plant program highlights exceptional trees, shrubs, vines, and perennials for the home gardener,” says Stephen Mostardi, Chair of the Gold Medal Plant Selection Committee. “These plants are easy to grow, pest free, and add beauty to the landscape for many seasons.”

Home gardeners and professional landscapers can purchase these plants with confidence knowing they have been carefully evaluated by the committee.

This year’s Gold Medal Plant exhibit at the 2019 Philadelphia Flower Show will showcase a dozen of these special plants.
“It’s a resource for people who attend the Show,” Steve explains. “They can experience the perennials, shrubs and trees that are going to be the most reliable to plant in their own yards. That’s the one distinctive thing about this exhibit. People gain knowledge about plants that will work for them throughout the region.”

The exhibit will be staffed by PHS with volunteers from the Gold Medal Plant Committee and Pennsylvania Certified Horticulturists from the Pennsylvania Nursery Association. “They’ll be able to talk in detail and answer questions,” says Steve.

All the Gold Medal Plants on exhibit at this year’s Show were grown at PHS Meadowbrook Farm. “The growers at Meadowbrook nurture this collection of plants from year to year,” Steve says.

Among the top plants in the Gold Medal exhibit is Polygonatum Odoratum Variegatum (Variegated Solomon’s Seal).  A 2015 Gold Medal winner, this perennial is durable, adaptable, and loves the shade but will tolerate partial sun.  It is best suited for woodland gardens or shady sections of rock gardens. Growing 2 to 3 feet tall, it slowly spreads throughout an area via underground rhizomes. Each stem features 8 to 15 variegated leaves. In late spring, small, bell-shaped flowers with a lily-like fragrance will blossom on the underside of the stem. In the fall, these flowers give way to black berries and the leaves change to a beautiful bright yellow. This perennial is noteworthy for its fragrance and low, gracefully arching stems.

Another exceptional Gold Medal Plant to become acquainted with is Itea Virginica ‘Henry's Garnet’ (Virginia Sweetspire).  “This native shrub was originally found locally, and since being awarded the Gold Medal Plant distinction in 1988 has become an important plant for naturalistic landscapes,” Steve notes. “It's particularly useful as an upgrade and replacement for the invasive plant known as Burning Bush.”

All Gold Medal plants are available at retail plant locations in the area. “People can use these as a mainstay in a perennial garden,” says Steve.

View the complete data base of PHS Gold Medal Plants here.


Posted on February 6, 2019

The Flower Show has historically been a showcase for new plants, counting the Poinsettia and the Chrysanthemum among its most popular introductions to the public in North America. The 2019 Show will be no exception. The New Plant Gallery will showcase the latest offerings of Proven Winners®; know Star® Roses and Plants, a leading genetics company involved directly in breeding roses, perennials and woody plants, and introducing plants from other breeders around the world; American Beauties Native Plants®, LLC, a partnership between Prides Corner Farms, Lebanon, CT, and North Creek Nurseries, Landenberg, PA, dedicated to promoting native plants; and Hort Couture®, a company that combines horticulture and fashion with varieties that blur the line between amazing performance and beautiful aesthetics.

Look for the Gomphrena Truffula™ Pink among the horticultural gems on display. Trialed and introduced by Proven Winners®, this plant is one of 18 new varieties being showcased in their display in the New Plant Gallery.

“Growing one foot to 24 inches tall, this plant packs on the color,” says Kerry Meyer, Program Director at Proven Winners.  “Compact in size, it works well in containers and smaller space gardens, but is still a fabulous landscape plant.  Truffula Pink has beautiful branching, and with its refined, tidy size, brings all the flowers closer together to create great color coverage. It looks and feels different and people want something new and really reliable. It’s a perfect container plant to attract pollinators.”  

Meyer sends out new introductions every year to four dozen universities and a handful of botanical gardens across the United States and Canada, including Longwood Gardens. In September 2017, Truffula Pink was selected to be introduced as a Proven Winners plant. Last summer, it was sent out to these trial gardens where it was planted in the ground and evaluated. “Everyone loved it. It was trialed in both landscape plantings and containers and was a standout in both planting types,” says Meyer.

The plant was very adaptable.  It did just as well in Miami, Florida, as it did up north in Minnesota and New England. It’s healthy, disease-resistant, and easy to grow, and fairly drought-tolerant. This low- key annual requires nothing more than a controlled-release fertilizer when it is planted, and water.  Not especially cold tolerant -- wait until after the last frost before planting, about the same time you plant petunias. It will bloom all summer, without deadheading, until a hard frost, and likes six or more hours of direct sun every day.  “Other than that, let it do its thing,” says Meyer. “It’s the standout this year, and certainly at the top of my list.”

While the Gomphrena Truffula Pink will not be available to purchase at this year’s Show, you’ll be able to find it at local nurseries this spring. Keep an eye out for this exciting newcomer.


Posted on January 16, 2019

Very few plants dare peek through the cold, hard earth to face the rain, snow and chilly air found here in Zone 7 during January and February. One brave perennial, the hellebore (Helleborus orientalis), faithfully appears every winter, drawn out by the sun.

“It’s a wonderful thing when you have just spent a week shivering next to the heater to go outside and find these little blossoms perfectly happy and totally immune to the cold,” says Sally McCabe, PHS Associate Director of Community Education. “Mine are happy here-- rain, snow or sleet!”

An evergreen, the frost-tolerant hellebore is in the buttercup family, Ranunculaceae, and is native to Greece and Turkey. This beauty has shiny, green leaves that weather the winter well. The plants grow in coarse clumps, reaching 12 to 18 inches tall and wide. Despite names such as Lenten rose, winter rose, and Christmas rose, hellebores are not closely related to the rose family.

Nodding downward, the hellebore’s 2.5-inch, saucer-shaped blooms open in an array of colors, including yellow, lavender, white, pink, green, purple, and a deep purple that appears black. Grown along a flowerbed or border, hellebores grace a garden when no other bloom will show its face. Many gardeners prefer to plant their hellebores on a hillside to view from below.

If you don’t have any hellebores to brighten your garden this winter, plan ahead for next year. Shop for them in February and March, when the selection is the largest and the plants are in bloom. You’ll be able to see the colors and choose your favorites. They’ll do well in part to full shade and humus-rich soil that is neutral to alkaline. This magical perennial is also adaptable to acidic woodland soils. Most are rated for USDA Hardiness in Zones 4 through 9.

Originally grown for their medicinal properties, hellebores are filled with alkaloid toxins, making these low-maintenance lovelies both deer- and rabbit-resistant. What more could you ask for?


Posted on December 5, 2018 

One of the most popular plants in the U.S. at this time of year is actually a tropical plant introduced to the American public at the first Philadelphia Flower Show in 1829. The Poinsettia has become a holiday horticultural icon. Joel Roberts Poinsett -- a botanist, physician, and the first U.S. Ambassador to Mexico -- spotted the brilliant red blooms on a trip south of the border in 1825. Enamored with their beauty, he shipped some back to his hothouse in Greenville, South Carolina.  It was there that he began propagating and sending the plants to friends and botanical gardens.  Bartram’s Garden received one of his plants and introduced it into commercial cultivation.

Sales of Poinsettia, or Euphorbia pulcherrima, now peak every year during the six weeks leading up to Christmas. With more than 100 varieties, including pink, white, burgundy, marbled, and speckled, there is a shade to please everyone’s color palette. Often mistaken for flowers, the colored parts of the plant are modified leaves, called bracts. New for 2018, Lyra™ Red and Mirage™ Red both flaunt deep red bracts. For those who love hot pink, Princettia Pink is a show-stopper.

Bundle up your Poinsettia carefully for its ride home from the nursery. Even a few minutes of exposure to temperatures below 50 can damage it. Place it in indirect light in a warm, sunny spot away from drafts. Position it to avoid touching cold windows. When the soil is dry to the touch, water the plant thoroughly.

Poinsettias can be mildly toxic. Prevent children and pets from chewing or swallowing the leaves.


Posted on November 14, 2018

Transitioning the conventional suburban landscape at the Philadelphia Navy Yard into an ecologically healthy, beautiful and natural area has been the primary goal for Tim Majoros, Associate Director of Public Landscapes at PHS. Tim and his team selected a palette of native plants to replace invasives. One of his favorites, Andropogon gerardii ‘Red October’, is a native cool-season grass that will work as well at home in a private landscape as it does on a larger scale at the Navy Yard.

Tim appreciates this perennial for its growing ease and tolerance of a wide range of soils and growing conditions. This plant produces a lot of growth in fertile soil, but is still adaptable to drier, infertile soils. It develops an extensive root system and has outstanding drought tolerance. “’Red October’ is ideal at the Navy Yard,” says Majoros. “It doesn’t require any input, and its leaves emerge gray to blue-green in the spring, turn to green with red highlights in the summer, and change to purplish-red in late summer. By fall, after the first frost, ‘Red October’ turns a vivid scarlet red,” he explains. Perfect for borders or buffer areas, this grass will grow to 6 feet in height and up to 3 feet in width.  Additionally, this easy-going plant will tolerate deer, drought, erosion, and dry soil, as well as proximity to black walnut trees.  

Consider adding this gorgeous, resilient native to your home landscape this season. Plant ‘Red October’ now through Thanksgiving.


Posted on October 3, 2018

Keep an eye out for the newest predator in town – the spotted lanternfly (Lycorma delicatula). This exotic pest is native to China, India, and Vietnam. It was first spotted in Berks County, Pennsylvania, in 2014, and has spread rapidly throughout the area. The spotted lanternfly feeds on more than 70 plants, including grapes, cherries, maples, and stone fruits, but the Ailanthus altissima, commonly known as the “Tree of Heaven,” is its preferred meal of choice.

People all over the five-county region are contacting PHS asking what they can do. If you have Ailanthus on your property, consider removing them, then treat the remaining “trap trees” with systemic insecticides.  This will offer the best long-term solution.

If you find just a few lanternflies and would like to kill them without controlling Ailanthus, swatting or crushing them is advised. These bugs are leafhoppers, so they can be hard to catch. For large populations, two kinds of insecticides will kill spotted lanternfly adults. Contact insecticides will kill them with direct contact; systemic insecticides are absorbed by the tree and kill the insects feeding on it.  Consult a certified pesticide applicator when in question.

Pennsylvania’s Secretary of Agriculture, Russell Redding, has estimated that the spotted lanternfly infestation could result in the loss of as much as $18 billion in agricultural revenue. Governor Tom Wolf has placed 13 counties around and including the Philadelphia area under quarantine, a move designed to stop the pest from spreading any further. It may already be too late; the spotted lanternfly has already been spotted in one county in Delaware, three in New Jersey, and two in New York.

Egg masses are laid during the fall and early winter and appear as one- to two-inch-long gray mud smears with 30 to 50 brown eggs underneath. This time of year, the egg masses turn dark brown and appear cracked and scaly.  Egg masses are laid on any hard surface, including cars and firewood. Always check these surfaces before traveling outside the quarantine area.

Follow these Instructions from the Pennsylvania Department of Agriculture if you discover eggs or the spotted lanternfly:

If you see egg masses: Scrape them off, double bag them and throw them away. You can also place the eggs in alcohol or hand sanitizer to kill them. Please report all destroyed egg masses to the Pennsylvania Department of Agriculture.

Collect a specimen: Specimens of any life stage can be turned in to the Pennsylvania Department of Agriculture’s Entomology lab for verification. Submit samples with the Entomology Program Sample Submission Form.

Take a picture: A photograph of any life stage (including egg masses) can be submitted to mailto:[email protected].

Report a site: If you can’t take a specimen or photograph, call the spotted lanternfly hotline at 1.888.4BAD.FLY (1.888.422.3359) with information regarding your sighting.


Posted on September 5, 2018

Not only will this shrub add a splash of color to your garden, it has a story to tell – one with local roots! Enkianthus perulatus ‘J.L. Pennock,’ known as the white enkianthus, has brilliant red foliage in the fall. This rare woody plant has showy white flowers in late spring, but it is the scarlet red foliage in the fall that makes it a show-stopper.

Enkianthus perulatus is native to Japan and Taiwan, where it grows in the mountains and woodlands. The white form, known as J.L. Pennock, was introduced by the Morris Arboretum of the University of Pennsylvania, where the original specimen lives today. The shrub was named to honor J. Liddon Pennock, Jr., proprietor of Meadowbrook Farm and a long-time Philadelphia Flower Show exhibitor and given to him on his 80th birthday in 1993. The plant that Liddon received on his birthday lives at PHS Meadowbrook Farm, where the perennial walk ends at the plant shop, and can be enjoyed by visitors to the public garden.

A PHS Gold Medal winner in 1999, this specimen is quite rare and not easily attainable. Coveted for its prolonged fiery autumn display, ‘J.L. Pennock’ has a long season of fall color that begins as a blush of burgundy in September, deepens in October, and finally turns dark red to scarlet in November.

In early May, pure white, urn-shaped nodding flowers appear in groups of three to 10, well after azaleas, dogwoods, magnolias, and redbuds have finished blooming. Bright green foliage with finely serrated leaves appear whorled on the tops of the branches.

The original plant at the Morris Arboretum is close to 100 years old. Shelley Dillard, Plant Propagator at Morris Arboretum, developed the propagation technique and held the patent on it until recently when it expired. Propagation is not easy and is most successful when cuttings are taken in mid-May.

Bernard Pettit, Associate Director of PHS Meadowbrook Farm, is currently propagating enkianthus perulatus at Meadowbrook. Time will tell and hopefully bear the fruits of his labor.

This elegant shrub is best used as a feature or specimen within a landscape. Because of its small size and slow growth rate, it is perfect for smaller gardens, foundation plantings, and hillside or rock gardens.  This low-maintenance cultivar requires little pruning and grows easily in acidic soil with full sun to light shade.  The plant is generally pest- and disease-free. It will mature at 5 to 10 feet tall with a 5-to 8-foot spread.