Category Archives: Native plants

Creating a Rain Garden

Do you want a garden that’s easy to install, looks good year-round, requires little maintenance, and helps prevent water pollution? Rain gardens are shallow depressions designed to soak up water and support trees, shrubs, and flowers that tolerate both wet and dry conditions. Often located near gutter downspouts or places where water puddles, rain gardens can also be landscaped into gentle slopes or run curbside along streets.

Giant hyssops, switchgrass, and goldenrod are some of the species growing in this rain garden at Cornell Plantations in Ithaca, planted next to its parking lot to absorb and clean polluted storm-water run off. Photo

Giant hyssops, switchgrass, and goldenrod grow in this rain garden at Cornell Plantations in Ithaca, planted next to a parking lot to absorb and clean storm-water runoff. Photo © Robin Simmen.

By absorbing the rain falling on your land, a rain garden can help reduce the storm-water runoff that pollutes our beaches, harbors, and estuaries. People sometimes confuse rain and water gardens. A rain garden is not a pond and won’t breed mosquitoes, which require 10 to 14 days in standing water to develop from eggs into adults.

The next time it rains, observe the direction of water runoff and where it collects on your property. Your roof may be directing most of the rain falling on it into gutters and downspouts feeding into a storm drain; if so, consider diverting this lost rainwater to irrigate a rain garden via underground piping, or construct a surface swale to channel this water to the garden. If your land slopes gently, you can create shallow terraces (one foot deep or less) for your rain garden or dig out a scallop-shaped bed for it in the hill.

The best plants for rain gardens are happy with a “drought and drench” lifestyle. Native plants are highly recommended because they are uniquely adapted to local weather fluctuations. Also, they require little or no fertilizer, are excellent food sources for pollinators, and provide habitat for birds, insects, and butterflies. Once established, their deep roots increase the water-holding capacity of the soil, hold it together, and prevent erosion. Water a rain garden as needed for the first year or so after planting. By the third year, you’ll never need to water it again!

For information on how to evaluate and amend your soil for a rain garden, do a percolation test to see how quickly water is absorbed, decide the dimensions of a rain garden, and prepare and plant the site, read the CCE Suffolk fact sheet on Creating a Rain Garden, and its companion  Native Plants for Long Island Rain Gardens.

Robin Simmen is a former Community Horticulture Specialist for CCE Suffolk. She can be reached at rlsimmen@gmail.com.

Growing Vines in the Landscape

When gardeners think of flowering plants, what usually comes to mind are annuals, perennials, and a few trees and shrubs. Although often overlooked, vines also have great potential in home gardens as they can create shade on pergolas, add vertical interest to arbors, adorn fences, or even serve as decorative ground covers.

Our wonderful native honeysuckle attracts hummingbirds.

Our wonderful native honeysuckle attracts hummingbirds.

To select a vine, first consider how it grows. Does it twine like a honeysuckle vine? Does it cling with aerial roots like a climbing hydrangea? Or does it produce tendrils like a clematis? Knowing how the vine grows will dictate the type of support you need to provide for it. Also think about the site: Is it sunny or shaded? Are you trying to attract wildlife? Do you prefer an evergreen plant? Here are a few vines worth considering:

Honeysuckle Vine (Lonicera sempervirens)

Our native honeysuckle vine is a great choice for a sunny site. It will happily twine its way in and out of a picket or chain-link fence, arbor, or trellis. As the botanical name suggests, this vine is evergreen in a mild winter. Honeysuckle vine is among the first plants to bloom in spring, serving as a bright beacon for Ruby-Throated Hummingbirds making their way back from southern climes where they overwinter. This vine grows 15 feet or taller and can withstand hard pruning. Some cultivars bloom continuously with red, orange, pink, or yellow flowers from spring until fall, providing all-season interest. Honeysuckle is prone to powdery mildew, but siting it in full sun with good air movement will keep the plant in good health. Aphids can sometimes be a problem. Be careful: Don’t confuse this native honeysuckle for the invasive, Asian species, Lonicera japonica!

Dutchman’s Pipe (Aristolochia macrophylla)

Dutchman’s pipe is another great choice if you’re looking for a native vine to cover a large area. This woody-stemmed, twining vine requires a strong trellis, wall, or pergola to support it. It will tolerate sun to shade in any garden setting, from a manicured garden to a tough urban site. Dutchman’s pipe was a popular choice in the 19th century, draping over large Victorian homes. The vine produces small, inconspicuous, purple-brown flowers that produce a unique odor and are often pollinated by flies that crawl into the “pipe” and get stuck within the hairs inside the flower. Once a pollinator is caught, the flower hairs wither and the insect can crawl out, covered in pollen. If you’d like to invite pipevine swallowtail butterflies to your garden, this is their host plant.

Dutchmans pipe creates a dense barrier of foliage.

Dutchmans pipe creates a dense barrier of foliage.

Passion Flower (Passiflora caerulea)

Blue passion flower, also known as hardy passion flower, is a unique option for a protected site. This passion flower is said to be hardy to USDA zones 7 and 8, but a harsh winter will probably knock this vine back to the ground. Passion flower climbs by tendrils, sometimes reaching 20 feet and higher. Unique purple-blue flowers are produced on new growth on and off throughout the growing season. If you’re looking for a native variety, Passiflora incarnata ‘Maypop’ is a hardy passionflower up to USDA zone 6. Pale-lavender flowers bloom throughout most of our growing season on Long Island. Maypop is also the host plant for the Gulf and Variegated Fritillary butterflies!

Climbing Hydrangea (Hydrangea petiolaris)

Climbing hydrangea is a great alternative to English ivy. Like ivy, this clinging vine uses aerial roots to attach itself to porous, vertical surfaces. You’ll be graced by large, lacy, white fertile flowers surrounded by a circle of larger, white sterile flowers in summer (think lacecap hydrangea). Plant a climbing hydrangea in sun to partial shade in rich, well-draining soil. Though this vine grows well on the trunk of a tree, it is not healthy for a tree to bear the weight of another plant. Instead of a tree, choose surfaces like wooden stockade fences, stucco siding, and stone walls. Climbing hydrangea is notorious for starting off slowly and establishing its root system for a few years before it takes off. Have patience, it’ll be worth the wait!

Morning Glories Ipomoea spp.

If you like to change it up every year, consider growing annual vines such as these in the morning glory family: moonflower (Ipomoea alba), cardinal climber (Ipomoea x multifidi), cypress vine (Ipomoea quamoclit), and the traditional morning glory (Ipomoea tricolor). Moonflowers open at night, providing bright-white, fragrant blossoms for evening dinner parties. Morning glories bloom in the morning and begin to fade by mid-afternoon. Gardeners often combine moonflower and morning glories together on one trellis to provide a continuous bloom day and night. Cypress vine and cardinal climber can be added for a pop of bright red to attract hummingbirds and other pollinators. Ipomoea spp. can be direct-sowed in a sunny site with good drainage. They grow rapidly, twining in and out of a trellis, arbor, or fence.

Cypress vine makes a great splash of color on a wooden fence.

Cypress vine makes a great splash of color on a wooden fence.

These are just a few of the many vines we can grow on Long Island. For more options and information on growing vines in home landscapes, check out our CCE Suffolk Horticulture Fact Sheet: Flowering Vines for Long Island: Indoors and Outdoors

Sandra Vultgaggio is Horticulture Consultant for CCE Suffolk. She can be reached by email at sib7@cornell.edu or by phone at 631-727-7850 x387.

Native Plants Champion Biodiversity

Ever wonder whether it really makes a difference whether or not you plant native species? Do native plants do a better job of hosting local insect communities than their non-native counterparts? Now a University of Delaware study shows that not only are natives much better at sustaining local insects, planting non-natives actually compounds the problem of declining species diversity because non-natives support fewer herbivore species across our landscapes.

A yellow swallowtail enjoying a purple coneflower. Photo by Mary Howe.

A yellow swallowtail enjoying a purple coneflower at the Children’s Garden at Suffolk County Farm, part of the National Pollinator Garden Network’s Million Pollinator Garden Challenge. Photo by Mary Howe.

The research was conducted by Karin Burghardt and Doug Tallamy, who is professor of entomology at University of Delaware and author of the bestselling book, Bringing Nature Home. Together they published their findings in a recent issue of Ecology Letters: http://onlinelibrary.wiley.com/doi/10.1111/ele.12492/abstract To conduct their study, they planted imitation yards with different common garden selections of both native and non-native tree species, and then collected data over a three-year period, measuring the herbivore communities and species found on those plants.

Tallamy said that finding young herbivores on a plant is a good indication of how that plant is supporting the local ecosystem, as opposed to finding adult insects, which could be on a plant for a number of reasons, such as resting or looking for a mate. “The relationship between the adult and food is far weaker than the relationship between immatures and food, so when you find adults on the non-natives, it doesn’t mean that much. When you find immatures, that’s what you should be measuring,” Tallamy said. “Those are the plants that are creating those immatures, and so we do get significant differences between the immatures that are using native plants versus the immatures using non-natives.”

He also stressed that that native plants always do the best job per tree of supporting herbivore communities when compared to their non-native counterparts. This study expands the understanding of that fact by looking at whether that lower per tree diversity is magnified further by non-natives hosting more similar communities across trees species and locations.

Burghardt said the goal of the research was to understand how the composition of the plants that homeowners plant in their yards affects herbivore communities. “What the gardens we constructed for the study are trying to replicate are landscaping decisions that people might make if they wanted to support native insect communities that in turn support much of the diversity around us.”

Learn more about how what you plant affects biodiversity at the Long Island Native Plant Initiative’s biennial Native Plant Conference on Saturday, October 24, at Farmingdale State College. LINPI’s Registration Flyer includes a symposium agenda and list of speakers.

Robin Simmen is Community Horticulture Specialist for CCE Suffolk. She can be reached at rls63@cornell.edu or at 631-727-7850 x215.