Taking Root: Delaware Botanic Garden’s Progress Report

 

Ambitious Master Plan of the Delaware Botanic Garden

 

Visiting the Delaware Botanic Garden in year two, one year later than my original visit, was an eye opener in the evolution of a major public garden. Even working as a landscape designer/installer, I was surprised at the great strides the difference of a year makes. For my first year post, go to DBG-From the Ground Up.

Just a year ago, there were large unplanted areas in the Meadow

The first thing that hits you as you enter is the wild centerpiece garden- The Meadow Garden- full of thousands of perennials that have matured with just 18 months or less of growth. Pollinators were zipping and buzzing around me as I wandered the winding pathways.

Horsemint (Monarda punctata) is a standout for structure and insect visits in the Meadow Garden

Meadow Garden

Closeup of the design of the Meadow

World renowned Dutch garden designer Piet Oudolf designed the showpiece Meadow Garden. The Master Plan describes it as  “an exuberant palette of mostly native ornamental grasses and herbaceous flowering plants that will create spectacular four-season color and textural saturations against a distant horizon”.

 

‘Matrona’ Sedum is a great late interest perennial

An old planting adage is “1st year-sleep, 2nd year-creep, and 3rd year-leap” and this second year is more than “creep”. All the perennials in the Meadow Garden have absolutely “leaped” this second year and appeared very established. Located on a sunny 2-acre area adjacent to the woodland edge, the goal was to plant sixty-five thousand herbaceous flowering plants and ornamental grasses to provide multi-season interest. The first thing that visitors will see entering DBG, the Meadow was completed this spring except for some small patches, with volunteers. It is already an undulating textural mass.

 

Close plantings discourage weed growth

The close planting will discourage weeds as the herbaceous perennials knit together as a ground cover.

‘Matrona’ Sedum edges a pathway in the Meadow Garden
Dog fennel (Eupatorium capillfolium) is a stinky feathery spiky plant that has seeded in between the perennials

Before the perennials form that weed smothering ground covering, opportunistic weeds, notably ‘dog fennel’ (Eupatorium capilifolium) have taken hold between the plants and tower over some of the new plantings. Volunteers were out in force when I visited recently and were pulling stinky dog fennel on a 95 degree humid day. Not fun for some 265 volunteers that work there throughout the year! Fortunately portable tents are set up to cast some much-needed shade and there is a camaraderie evident in everyone you speak to.

Lots of Dog Fennel to remove

 

A volunteer is mulching with pine fines; In the distance, you can see the shade tents
Volunteers can work under a canopy from the hot summer sun, photo from Janet Draper
Water hydrants are located conveniently throughout

Pollinators Abound

The native perennials are thriving and even in mid August when color is hard to find in a perennial border, texture and color abounded throughout the insect heavy plantings. Camera in hand, it was hard to keep up with all the native pollinators that were buzzing around.

Butterfly on Liatris microcephela
Monarch on Rattlesnake Master (Ernygium yuccafolium)
Dragonfly caught on Little Blue Stem Grass (Schizachyrium scoparium)
Swallowtail on Stokes Aster (Stokesia)

New Hoop Houses

Brand spanking new hoop houses were just erected with a gravel base that can be put to use this winter in growing new transplants (plugs), cutting propagation, and overwintering of young, frost susceptible plants.

Inside one of the new hoop houses

 

Pine straw and pine fines are being used as mulch

Woodland Garden

Eradicating invasive plants, installing pathways, careful tree removals, and  shade plantings have been progressing in the Woodland Garden.  With a phased implementation of DBG, the Meadow Garden is the first phase and the Woodland Garden is close behind, so intensive shade loving plantings are being installed along the newly placed pathways. Curving volunteer constructed stone walls make a nice addition as well as holding soil in place along many of the pathways.

Some areas of the Woodland Garden will showcase only native plants and others will contrast natives along with non-native plants from Asia and Europe. Plantings will be planted from the upland areas to the nearby water’s edge of Pepper Creek.

Plantings along with irrigation are being installed in the Woodland Garden
Irrigation is being installed

Trimmings and prunings are being recycled  and reused as sculptural elements in bird’s nest structures and a porcupine “tree” is a sculptural stopping point on the path.

Birds Nest of twigs that would otherwise be thrown out
Funnel spider web in bird’s nest
Porcupine Tree

Learning Garden

A wetland area will be an outdoor classroom called the “Learning Garden”. A high school class of seniors has already been hosted in a learning experience there. Interactive programs and living classrooms encouraging active involvement with nature is a major component of the DBG goals.

Organic

There have been no applications of fertilizers, pesticides or fungicides thus far.  For pathway weeds, a  20% Horticultural vinegar was used which was quite effective.

Eradication of weeds in pathway with horticultural vinegar

Whats Next

A projected opening date of September 2019 is only a year away and lots of money and volunteer hours will be needed in the meantime. A fall tree planting campaign, planting of the dune gardens, and the east woodland border are next on the agenda. Frequent fund-raising is being done  to feed the volunteer efforts and plantings. If interested in donating, go to Make a donation.  This is an exciting opportunity to get on the ground floor supporting or volunteering at  the incredible new Delaware Botanic Gardens.

A volunteer working; A temporary visitor center is in the distance
Artist rendering of projected visitor center, photo courtesy of DBG

Got Milk…….. Weed?

Common Milkweed

One of the most beautiful flowers, both in flower and seed pod, as well as great importance to wildlife, has been relegated to the roadside for years and virtually ignored. Asclepias syriaca, or common milkweed, is struggling and harder to find because wild areas are disappearing and roadsides are  regularly mown. “Familiarity breeds contempt” is a common saying and one that I would apply to this plant. Only when something becomes scarce do we appreciate it, and I can see that happening with milkweed. But there is a sea change coming down the pike and people are being urged to plant this “weed”.

Colony of Milkweed

Acknowledged as a primary source for survival of many insects, notably the Monarch,  people are waking up to its integral role in supporting other wildlife. See my post Monarch Waystation on the many reasons to plant milkweed for Monarch survival.

Milkweed Facts

  • Milkweed is the only plant on which monarch butterflies will lay their eggs, and it is the only food source for monarch caterpillars
  • It grows in colonies that expand in size every year; each individual in a colony is one side shoot of a large plant and are genetically identical or a clone; one large branching underground rhizome connects the entire colony
Monarch caterpillar munching on a milkweed
  • Surprisingly, the flowers are extremely fragrant and you can smell a colony long before you see it
  • Although one shoot may have between 300 to 500 flowers that make up the umbels, only a few of these develop into pods

    Milkweed pods are positioned vertically

     

  • Vegetative and flower growth is rapid, but the pod development is very slow and held on the plant for many weeks
  • The pods are held vertically to the plant and hold many seeds; germination of these seeds is very sparse; milkweed more likely expands by underground rhizomes than from seed
  • The nectar is very high in sugar content, 3% sucrose, and the supply is constantly being renewed over the life of the flower; the flowers produce much more concentrated nectar than the many insects that feed on it could ever remove
  • Milkweed teems with insect life, providing food and micro habitat to hundreds of insect varieties
  • At least 10 species of insects feed exclusively on milkweeds, notably the Monarch butterfly caterpillar
  • The adult Monarch lays its eggs on the leaves of common milkweed, the larvae live on its leaves and milky sap, and the adult Monarchs drink from the flower nectar, although adults will drink from other flowers
  • The latex milky sap from the milkweed is extremely toxic to other wildlife and is concentrated in the tissues of the Monarch which protects it against predators
Milky sap exudes down the stem
  • The adult Monarch migrates south. East of the Mississippi, they fly as far as 4,800 meters to over winter in Mexico, often to the same tree location
  • This relationship between the milkweed plant and the monarch butterfly makes the pairing a symbiosis, where they become one entity instead of two separate organisms. Most importantly, without the presence of the milkweed plant, monarchs would go extinct.
Asclepias incarnata
Asclepias incarnata
Common Milkweed in December

Other Varieties of Milkweed

Asclepias tuberosa, orange-flowered Milkweed below is probably my all time favorite for drawing insects and pollinators to the garden early in the season, around June for me in the mid-Atlantic. A long-lasting cut flower, I scatter it through my borders to brighten up early summer plantings. It comes in an all yellow version called “Hellow Yellow”.

Yellow butterfly Weed "Hello Yellow"
Yellow butterfly Weed “Hello Yellow”

Another milkweed which is a conversation piece oddity is Asclepias physocarpa (changed to Gymnopcarpus Physocarpus, a mouthfull!), or Hairy Balls. Forming puffy seed balls two to three inches in diameter, the orbs are covered with hairs and are quite bizarre looking. Perfect for flower arranging, the cut branches are quite expensive to buy from a florist, but easy to grow. A favored host of the Monarch butterfly, I always try to grow this plant for the odd looking pods. The caterpillars seem to prefer this variety over all others.

The pods of Hairy Balls or Balloon Plant are a conversation piece

Monarch caterpillars cover the Balloon Plant Milkweed

Tropical milkweed, Asclepias curassavica, is commonly seen growing in Florida and has bright red-orange and yellow flowers and is also a great nectar source. The leaves are narrower and the plant produces many more seed pods than the common milkweed.

Tropical Milkweed
Tropical Milkweed
Sign at nursery for Swamp Milkweed
Swamp Milkweed has a narrower leaf than common
Swamp Milkweed growing by pond

 

Delaware Botanic Gardens- From the Ground Up

Traveling the quiet back roads of Sussex County in southern Delaware, through residential developments, I didn’t expect to see a world-class botanic garden taking shape. At the end of Piney Neck Rd, there it was for all the world to see, ‘The future home of Delaware Botanic Gardens at Pepper Creek’. My motive for searching down the steamy country roads was the opportunity of enjoying an alternative beach activity. Staying at Rehoboth Beach each summer for a week, I tire of the outlets and surf and look for other entertainment. And if there is a garden involved, all the better!

An aerial view,  photo courtesy of Delaware Botanic Garden

Within the gardening world, rumors were flying of the establishment of a new Botanic Garden in Delaware. In the works for years starting as a grass-roots movement, it is remarkable to note that the project began just four years ago, and has since grown into a tax-exempt nonprofit organization. Funding has start to flow with grant monies, most notably from Longwood Gardens, but like any public garden, they always need more. The ground breaking  was launched in December 2016 and the hard work of creating an ambitious 37 acre botanic garden featuring natural woodlands, vernal ponds, meadow gardens and 1000 feet of waterfront has begun.

Looking out into Pepper Creek

Situated along Pepper Creek, which flows into Indian River Bay, the parcel of land leased from the Sussex County Land Trust for $1 a year, has an unusual feature: a hill.  As anyone knows, driving through this part of Delaware, any elevation of the land is a rare event. This valuable feature slopes down through a twelve acre hardwood forest to the water’s edge to a wetland marsh and a tidal creek-great territory for a garden. In the hardwood forest, a winding walkway beneath pine groves and alongside century-old southern red oak and sassafras trees provides a welcome respite from the hot sun of summer.

Pathways through the woodland area; native wildflowers are being planted here, photo courtesy of Delaware Botanic Gardens

Building the new Botanic Garden in stages over a 10 year period, any experienced gardener knows this time line makes sense. Establishing a garden takes time and more importantly for a garden this size…..tons of money.  With a goal of being self-supporting with donor help: membership dues, admission fees, gift shop and online sales, and event rentals, there is still a huge need for the initial costs of building, installing, and planting, as well as volunteer hours.  If interested in donating, go to Make a donation.  This is an exciting opportunity to get in the ground floor of supporting the incredible new Delaware Botanic Gardens.

Proposed visitor’s center surrounded by expanses of meadow,  photo courtesy of Delaware Botanic Garden
From left to right- Janet Meenehan Point, Gregg Tepper, and Ruth Rogers Clausen
Blue crabs live in the nearby water, photo courtesy of Delaware Botanic Gardens

When I visited this past August, I could see many enthusiastic volunteers in action in hot, humid, and unbearable weather, and yet so excited about working there. From laying stone for beautiful dry laid walls, to planting and watering new transplants, everyone is welcomed and appreciated.

Ruth Rogers Clausen enthusiastically shows off the woodland area, one of the first areas to open to the public in 2019

Gregg Tepper, the DBG horticulturist,  comes to DBG from Mt Cuba Center in Hockessin, Delaware, where he served as horticulturist, and director of horticulture. An articulate promoter of native plants, he is the driving force for using everything on site in a sustainable way. Brush, log chunks, and tree trunks are not discarded but used in very innovative ways. The hedgehog was my favorite. A large downed tree with multiple protruding branches is a canvas for a future hedge hog sculpture. Brush branches, instead of being discarded, were deposited in open areas of the woodlands to create giant birds nests. A great way to entice kids to enjoy the woodlands! The log chunks, Gregg said, could be used as edgers for the woodland pathways.

Nests of brush are being constructed in the woodland area using cleared brush, photo courtesy of Delaware Botanic Gardens

Can you see it? The start of a hedgehog sculpture!

 

Beautiful dry laid walls are lining the woodland walkway, all done by volunteer Don Klima
Holding area for new plants

The Master Plan includes nationally and internationally recognized leaders in the field of garden design, architecture and landscape architecture, notably Piet Oudolf, an influential Dutch garden designer, nurseryman, and author. When I heard that Piet Oudolf was involved in the planning, I was impressed that DBG had snagged such a high-profile plantsman. Volunteer Barbara Katz was the impetus behind getting Oudolf involved. Known best in the U.S. for his design of the High Line and a leading figure of the “New Perennial” movement, Oudolf is renowned for using broad painterly drifts of hard-working perennials and grasses. Oudolf designed the centerpiece Meadow Garden at DBG.

The Meadow Garden

The centerpiece Meadow Garden is described on the Delaware Botanic Gardens’ website; “Taking advantage of the upland plateau’s openness, a spectacular meadow filled with broad bands of native grasses and seasonal flowering blooms will form the sweeping center of the site and the gateway to the Woodland Gardens. Herbaceous plant species native to Delmarva and surrounding areas will be featured in a breathtaking design. This open garden, designed by the internationally acclaimed Dutch plantsman Piet Oudolf, will support thousands of pollinators, butterflies, and birds. One of the primary objectives of this space, located in the Atlantic Flyway, is to encourage the bird population and the insects they need to survive”.

For a great day by day on-line progress of the planting of The Meadow, go to YouTube.

An army of volunteers planted 17,000 plants in the initial phase of the Meadow Garden, photo by Ray Bojarski

According to Raymond Sander, President of Delaware Botanic Gardens, when Oudolf first saw the proposed meadow site, he exclaimed, “It is beautiful, but we can make it more beautiful!! This is infinity!” And the meadow is indeed in the shape of an infinity sign, bisected by pathways.

Hand drawn meadow design by Piet Oudolf
Left to right: Raymond J. Sandler, President of DBG, Piet Oudolf, and Sheryl Swed, Executive Director of DBG, photo by Ray Bojarski

Located in a sunny two acre site in the center of the Gardens, the Meadow Garden will be planted with 65,000 herbaceous flowering plants and ornamental grasses that will provide a tapestry of color throughout the year.

Perusing the Master Plan, by Bill Jones & Ruth Clausen, a board member and volunteer

Hand drawn artistic plans of the meadow by Piet Oudolf were available when I visited and as a landscape designer myself, I was delighted that they were hand drawn and not computer generated. They were works of art.  Print these plans on silk scarves and sell them in the planned gift shop!

A closeup of the hand drawn plan of the meadow by Piet Oudolf

When I was there is August, volunteers were preparing the ground, leveling and spreading pine fines which is partially composted pine bark. Its fine texture allows water to pass easily through while providing a protective covering for the soil. Providing nutrients, decomposing easily, the fineness of particles doesn’t compact like other pine bark mulches.

The dark color is pine fines
Planting the meadow takes lots of wheelbarrows, Photo courtesy Janet Draper

Volunteers, led by DBG Horticulturist Gregg Tepper, came out to prepare and plant the meadow the week of September 5. When Piet Oudolf arrived to inspect the site, Piet decided to first have the volunteers build and smooth out the elevated hill in the middle.

The much anticipated first phase planting of the Piet Oudolf meadow, staffed by an army of volunteers, began.  Referring to the comprehensive plan, orange marks were painted on the ground detailing the proper placement of plants and orange flags were placed if the plants were currently on hand. White flags were placed  designating quantity and identity of plants still to come. The second phase of planting will occur in June 2018.

Photo courtesy Janet Draper
Melanie Ruckle and Patrick Gravel planting the meadow with grasses, photo courtesy Janet Draper

As any gardener knows, the work of digging thousands of holes is time-consuming and hard on your wrists. With the help of a power auger, the holes were dug much more efficiently.

A power auger made the plantings go quickly, photo courtesy Janet Draper

Master Plan/Field of Dreams

The Master Plan is the result of a twelve-month process led by Rodney Robinson and Allan Summers of RAS Landscape Architects. Organizing the site and guiding the process of long-term plantings, it identifies the different types of gardens and plant collections.  In a  zone 7b garden, many different types of plants can be planted as long as deer are controlled, and a deer fence is being planned, I was glad to hear. You don’t want your hard work and money to be devoured by a voracious deer population. The main focus of the Master Plan vision is as follows:

  • Always be beautiful
  • Be innovative and forward thinking
  • Provide an outdoor wetlands classroom for both passive and structured educational experiences
  • Connect children and adults to nature
  • Demonstrate the intersection between horticulture and ecology
  • Reach out to a rapidly growing year-round community
  • Attract a wide audience and encourage repeat visitation
  • Accommodate festivals and special events
Butterfly on newly planted Lobelia in Woodland Garden

The surrounding areas are being rapidly developed with residential communities and is a highly attractive area for retirees so I can see that many people will take advantage of the Botanic Gardens proximity. It is also a great resource to draw volunteers from. Buffers of plantings are planned to screen the Gardens from neighboring properties and Piney Neck Road.

Master Plan , photo courtesy of Delaware Botanic Gardens

From the entrance area, multiple pathways will wind through, connecting pedestrians to all the garden areas. Water is a recurring theme throughout the Gardens as showcased in the proposed Cascade Garden, the Bald Cypress Garden, and the unifying Freshwater Pond that will serve as a focal point. Garden components included on the Master Plan:

  • Parking and Rhyne Garden
  • Visitor and Events Center, Cafe
  • Meadow Garden
  • Edge Garden w/ Amphitheater
  • Gallery Garden
  • Demonstration and Display Garden
  • Coastal Living Garden
  • Cascade Garden
  • Freshwater Pond
  • Bald Cypress Garden
  • Discovery Garden
  • Native Plant Garden
  • Outdoor Wetlands Classroom
  • Maze
  • Woodland Gardens-Kalmia-Azalea Knoll, Pine Savannah, Grotto, Oak Glade, Magnolia Forest, Delmarva Bay Gardens, Asian-European Bank
Remains of a horseshoe crab on the shoreline

 

Quite ambitious, but with all the enthusiasm, knowledge, and verve pushing this project along, I have no doubt that it will happen.

As a landscape designer, I am always called in after the house is built and the owners are ready for the planting of the landscape. But at the DBG, their priorities are reversed – the landscape comes first and then the buildings. Buildings and structures are important but in the long-term, the landscape plantings that can take years to mature should take priority.

When it opens in 2019, the DBG will include the just planted colorful natural meadow, extensive plantings in the woodlands, and pathways in and along the edge of the existing woodlands, a living outdoor wetlands classroom, and a temporary visitors center. Additional gardens, water features, and more permanent structures will be added in the following years. Serving as a resource for local farmers, gardeners, and homeowners, I can’t wait for the opening of the Garden Gates!

Photo by Ken Arni

Many thanks to Ruth Rogers Clausen for her hospitality in opening the garden to several beach weary gardeners. Also, thanks to Janet Draper for her photos and information on the first phase of meadow plantings and Sheryl Swed for additional pictures.

 

 

Honeybee NectarFlow-Black Locust Trees

Black Locust bloom

Planting peas by St Patrick’s Day is an American farming tradition that goes way back and I can remember my father relating this age-old practice. He spent his childhood on a farm and knew all the old-time ways. I didn’t have any beekeeping relatives, but if I had I am sure they would have told me to super my hives (adding extra storage boxes for nectar) when the Black Locust blooms. Beekeepers, like farmers, still look outside in the natural world to gauge how to manage their honey crop.

The lower large box is a brood box, where the queen lays eggs, and the upper boxes are supers

The Black Locust tree, Robinia pseudoacacia, is famous for producing a fruity and fragrant light green honey. Native to the Eastern United State, I always look for this tree to bloom in the spring as a sign that “honeyflow” or “nectarflow” is starting for my honeybees.

Honeybees love native Black Cherries that bloom at the same time

An abundance of nectar sources blooming in profusion means a nectarflow is starting with the bees collecting excess nectar. When bees bring in more nectar than they need or can use, that is when a beekeeper rejoices and can remove the extra stored honey for themselves. Contrary to widely held opinion, bees only produce excess honey in the early spring or occasionally in late summer, and beekeepers harvest in July for much of the United States. In southern states, where native flowering is much more abundant over a longer time period, beekeepers can get two harvests.

Honeybee nectaring from a late nectar source-Dahlia

The Black Locust tree is native to eastern and southeastern North America, but has spread throughout the United States and much of Canada and can be invasive. They grow quickly on roadsides and fields and now the creamy heavily scented branches are hanging heavy over a road that I travel every day. Most people would zip by and not pay any attention at all to these beautiful trees as the blooms are usually high up in the canopy. But I stop and whip out my camera to zoom in on these beautiful blossoms!

The flower racemes pull down the branches of the tree

Last year, because of the fickle weather, Black Locust didn’t bloom in the great abundance that I see this year, so I am hoping for a good honey harvest. But this spring we have had lots of spells of rainy cold days when the bees can’t fly and that might cut short the nectar flow.

A warm and sunny spell during honey flow means that a strong hive can fill a honey super with nectar in two days! Remember…. that is nectar. Ripe honey has had its water fraction reduced greatly by bees fanning nectar to increase water evaporation to produce the sugar concentration necessary to produce honey. Once honey is ready, the bees cap over the top with wax.

Ripe honey cells are capped by wax in the upper left hand side; on the lower right are growing brood

Blooming for about 10 days between April and June, here in the mid-Atlantic, the racemes of blooms of Black Locust opened in early May. Even before the flowers opened, the bees started collecting pollen from the tree which they need to feed their growing brood or larvae. Worker bees will flock to the flowers for the abundance of nectar that they produce, once the days turn warm and sunny and browse from other flowering trees and vegetation, like the Black Cherry. With the onset of blooming, bees start producing wax which requires several times more nectar than honey. And bees need honeycomb built first before storing nectar. The purpose of a spring flow, for the bees, is to provide food for the rest of the year, not honey for the beekeeper!

The racemes of the Black Locust flowers hang down 8 inches

After this big burst of native bloom, there is usually a summer dearth until goldenrod, asters, and other late bloomers appear. That is why gardeners should plant summer bloomers to supplement their diet. Plant those Zinnias, Sunflowers, etc. Go to Plant These For The Bees.

Plant These For The Bees poster available at TheGardenDiaries Etsy Shop

Asters are an important late season nectar source for all pollinators

Healthy hives may produce queen cells in preparation for swarming, as the spring nectarflow builds; their normal method of making new colonies. The old queen and a large swarm of bees will go off and begin a new hive. See Swarming of the Bees.

Producing more queens prior to swarming
Bee swarm in my backyard tree

Interesting and Surprising Facts About Black Locust

  • Abraham Lincoln, as a young man, built up his muscles splitting logs from Black Locust trees for firewood and fence posts

  • Extremely hard wood, one of the hardest and rot resistant in North America, the wood is valuable for floors, boats, fence posts, and furniture

  • A member of the Fabaceae (pea family), the tree has nodules of nitrogen-fixing bacteria on its roots which make it an excellent species for re-vegetating poor or damaged soils

  • Newly cut wood has an offensive odor which disappears with time

  • The flowers are eaten in Japan, France, and Italy, battered and fried as beignets or in tempura

  • The bark, wood, and leaves are toxic to livestock and humans, so farmers remove them from their fields

  • Black Locust blooms along with privet, multi-flora, blackberries, honeysuckle, and other native vegetation to produce the abundance of available nectar for pollinators; so even invasives play a role in supporting pollinators

  • Black locust is an interesting example of how one plant is considered an invasive species even on the same continent it is native to

  • Racemes of flowers can hang 4-8 inches long and intensely fragrant smelling like an orange tree

  • Highly tolerant of pollution, the tree is planted in Europe and produces the acclaimed ‘Acacia Honey’

  • One of the best woods for burning in wood stove, it has little or no flame and can burn when wet, burning at a comparable temperature as coal

  • Compounds in the heartwood allow the wood to last over 100 years in soil

 

 

 

 

Native vs Non-Native-Which is Better for Pollinators?

butterfly
Tithonia, Mexican Sunflower, native to Mexico and Central America, is one of the top insect drawing plants in my garden

Native Vs Non-Native

Native or non-native in the garden: Which is better? Simple- everyone knows the answer to that question…Natives of course! As gardeners, we have been bombarded with information about the value to wildlife of native plants and the more natives the better. But the definition of natives has always been fuzzy to me. Are natives plants that originated within our region, state, or North America? Or things that predate Europeans settling North America? Or does it mean plants indigenous to a particular habitat or ecosystem? And how about cultivars of native plants-like different varieties of Anise Hyssop which is a North American native? There are no easy answers to these questions.

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‘Pink Panther’ Anise Hyssop is a bee magnet
DSCN1921
Liatris is a great native wildflower that I grow for bee value

I have always been skeptical about the native plant zeal and ready to challenge it after my observations of over 50 years of gardening experience. My blog post on the benefits of planting Butterfly Bushes stirred up some controversy. I acknowledge that Butterfly Bush provides only nectar and not foliage value to caterpillars as a host plant. But I still urge people to plant Butterfly Bush because deer won’t touch it and the butterflies flock to it and I enjoy the plant for its beauty and ease of growth. There aren’t many flowering shrubs that deer leave alone which makes it valuable as a landscape plant.

IMG_9271
Pipevine Swallowtail on Butterfly Bush flower

I always deferred to the experts about native plants because anecdotal evidence is not the same as peer reviewed scientific articles.  So, I had no numbers to back up my belief gained from experience. Planting a diverse assortment of flowers- be it perennials, vines, annuals, trees, or shrubs or native and non-native to provide a healthy and beautiful habitat was always what I have practiced. My decisions on what to plant was determined by whether the plant was appropriate for the location and environment, not fussy, and that it wasn’t invasive.  Invasive means that a plant is spreading prolifically and undesirable or harmful to the habitat.

P1060383
A roadside field of invasive Purple Loosestrife,, Lythrum salicaria, originally from Europe
P1060381
Invasive Japanese Beetles feeding on Lythrum

Plants For Bugs Article

My longtime observations of planting a diverse selection of plants, both native and non-native, was recently backed up by an article, “Plants For Bugs: all in the mix” by Helen Bostock, who is a RHS Senior Horticultural advisor, from across the pond. Bostock says the average UK garden contains around 70 percent non-native and 30 percent native plants. I couldn’t find the U.S average, but I think it is probably very close to that same percentage. Bostock concludes that native use is on the rise, especially with the ‘back to the wild’ environmental movement, and ongoing education of home consumers of landscapes. I see it happening in my own practice of landscape designer with more and more requests for butterfly/wildlife friendly landscapes and less requests for manicured formal gardens. Gardens are still very unlike natural habitats but have a much greater diversity of plant species than their surroundings which have been degraded with development encroachment.

Disney wedding 163
Zinnias are not native to my area but pollinators love them

Bostock’s research concludes after studies spanning four years that a mix of plants from around the world may be the most effective way to sustain pollinators. This was no surprise to me. The native bandwagon has acquired mystical connotations in the past 10 years and claims that natives use less water, are disease free, and low maintenance have been made over and over.

P1060243
I am slowly removing turf and planting meadows with native plants on my property

But what role do garden plants (both native and non-native) play in supporting wildlife?  Views differ on whether planting native plants only is necessary for the most wildlife friendly garden. This was the question posed by the Wildlife Gardening Forum in the UK and they set up a field experiment designed to test whether the geographical origin of a plant affects the numbers and diversity of insects and other wildlife.

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Pollinating fly on mint flower

Conclusions

This is what the RHS study has concluded:

• Research reveals a mixture of native and non-native ornamental plants may provide the best resources for pollinating insects in gardens
• Native plants are not always the first choice for pollinators visiting gardens
• Non-native plants can prolong the flowering season providing an additional food source

Surprising results for many!

The basis of a garden’s health and vigor is determined by invertebrates, animals lacking a backbone. The more critters making a home or just stopping by for a refueling visit, the healthier your garden is to the environment and your health and well being.

P1050823
Dragonfly on waterlily

 Findings and Messages

For all pollinator groups on all treatments, greater floral resource, either native or non-native, resulted in an increase in visits. There was, however, a greater abundance of total pollinators recorded on native and near-native treatments compared with the exotic plots.

P1060158
Allegheny Vine, Adlumia Fungosa, is an endangered North American native, closely related to Bleeding Heart

Exotics were notable in extending the period of bloom which is really important to attract insects all season long.

The takeaway here – use site appropriate native plants when possible, understanding that some are a bit more boisterous than others, but add exotics where appropriate to enrich and extend the season. Gardens can be enhanced as a habitat by planting a variety of flowering plants, tilted towards native and near-native species.

 

The Great Butterfly Bush Debate

Butterfly on butterfly bush bloom
Butterfly on butterfly bush bloom

Butterfly Bush, Buddleia davidii, has been widely bashed from garden writers, ecologists, and conservationists. Attacked from all sides by master gardeners and other garden professionals, I am sticking to my guns on the benefits and pleasures of planting it. “An invasive thug that only provides sugar-water”: That is the complaint that conservationists use to discourage you from planting this shrub.

Swallowtail
Swallowtail

As a preferred late summer nectar source and butterfly magnet, I enthusiastically promote it in my butterfly presentations for its many virtues. An important tool to draw butterflies, I also plant many natives next to it that can act as host plants.

Swallowtail on bloom
Swallowtail on bloom

One of the few flowering shrubs that deer will not touch, I use it all the time in my landscape designs as an easy to grow, beautiful, fragrant, disease free, flowering shrub. The only care required is a general whacking back of the whole shrub in the early spring to encourage bushiness and flower production. Over 100 varieties provide a wide palette of forms, sizes, and colors, to choose from. The dwarf varieties are especially valuable for small gardens and containers, like ‘Blue Chip’ and ‘Pink Chip’, growing only 4 feet tall. And these are sterile varieties that will not set seed.

Butterfly Bush 'Pink Chip'
Butterfly Bush ‘Pink Chip’

Why do butterflies love this plant? Providing loads of sugar water , the nectar filled nectaries, are shallow which is important to accommodate the short-tongued butterfly. Butterflies can reach the copious nectar easily which has a high percentage of sucrose, an energy fuel. Attractive to moths, bees, and other insects, this plant is valuable to all kinds of wildlife, not just butterflies.

Miss Molly Butterfly Bush in border
Miss Molly Butterfly Bush in border
Miss Molly adds a new color, raspberry, to the mix
Miss Molly adds a new color, raspberry, to the mix

Native to Japan and China, butterflies don’t care where their source of nectar hails from. In my post Butterfly Watching, I noted that butterflies have taste receptors on their feet to locate food and if their foot’s receptor and the molecule match, the butterfly eats. So, the plant’s origin is irrelevant and is an attractive food source. As humans, we eat many non-native plants, why can’t a butterfly do the same?

The butterfly bloom nectaries are numerous and easily accessible
The butterfly bloom nectaries are easily accessible

Invasive thug or non-native adaptive? There are several ways of looking at this plant. I know that it invades into mostly disturbed areas where lots of aliens/invasives have already taken over and is known as an invasive in over 25 states. But still, it is providing an important late summer source, when it is sorely needed. The other short-coming that ecologists claim is that butterfly bush only provides nectar, not acting as a host plant for the caterpillar to reproduce, but that is also true of other native plants.

Monarch caterpillar on milkweed
Monarch caterpillar on milkweed

Butterfly Bush seeds do not ripen until dry weather during the following spring. Worried by the potential for invasiveness? Then you can dead head it before the seeds ripen in the spring or cut the whole bush back which will eliminate the spread of seeds into adjacent habitat. Colonizing disturbed ground sites such as railway lines, quarries, roadsides and waste ground, butterfly bush can form dense stands of shrubs that butterflies flock to. What’s not to like!? Here is the position of the UK’s Butterfly Conservation on their website:

“Buddleia provides an important nectar source for adult butterflies, moths and other insects in townscapes and the countryside. This has become increasingly relevant because wildflowers have become so depleted following habitat loss and the general lack of nectar sources in the countryside. It also brings enjoyment to many people, both because of its heavy-scented and beautiful blooms but also because of the butterflies and other insects it attracts. It therefore plays a role, alongside other non-native garden plants, in helping to maintain or restore the link between people and native UK wildlife such as butterflies. In gardens, Buddleia is often pruned annually thus removing seed-heads and reducing the potential for seeding.

Buddleia is not important as a caterpillar food-plant and cannot replace naturally occurring wildflowers, which are crucial to provide a variety of nectar through the year as well as being food-plants for caterpillars. Buddleia can cause serious problems on some important conservation sites, especially brownfield sites. It needs to be controlled in these and other semi-natural sites to allow natural vegetation to develop. The cost of control can sometimes be considerable.

In reaching a position on Buddleia it is important to weigh up the undoubted benefits it brings in garden situations against the possible risks to wildlife habitats. It is also important to recognise that Buddleia is already naturalised and well established across much of the UK.

In view of its value as a nectar source, BC will continue to recommend its planting in gardens alongside other butterfly-friendly non-native plants, but will avoid giving it undue prominence and will give advice on its management and control.

Miss Molly
Miss Molly

A sea change is going on with some conservationists, that we are dealing with a changed world and there is no way to go back to an idealized world of  stable co-habitating species. From the beginning of time, species have moved around, finding new territories, and creating new ecological niches. Invasive species, like it or not, are part of nature. Serving an ecological purpose, whether it aligns with our idea of what it should look like, isn’t relevant to nature.

Wisteria Lane Butterfly Bush, a weeping Butterfly Bush

And according to the Royal Horticultural Society:

• Research reveals a mixture of native and non-native ornamental plants may provide the best resources for pollinating insects in gardens
• Native plants are not always the first choice for pollinators visiting gardens
• Non-native plants can prolong the flowering season providing an additional food source.

So, armed with this knowledge, you make the decision.

Swallowtail on bloom
Swallowtail on bloom