Native shrubs Virginia sweetspire, or Itea virginica, and oak leaf hydrangea,… (Photo courtesy Carol A.…)
Ecology is on many gardeners' minds these days.
Gardeners who value the science of relationships between living things and their environments increasingly want to know more about those connections — how toxic chemicals worsen a yard's overall health and why bees, birds and butterflies are crucial to our daily lives, for example.
To help gardeners sort through the options for gardening naturally and responsibly, the Virginia Horticultural Foundation spotlights the theme "Natural Gardens" during its Home Gardener Day 8 a.m.-3 p.m. Thursday, Jan. 16 at the Marriott at City Center in Newport News.
"We have a responsibility to support the land that we depend on for our own survival, and that responsibility includes thoughtful choices about how we landscape our own tiny spot of Earth," says Carol Heiser, habitat education coordinator with the Virginia Department of Game & Inland Fisheries.
During Home Gardener Day, she discusses "Habitat at Home: Landscaping for Wildlife." The conservation program, outlined in great detail at http://www.dgif.virginia.gov/habitat, encourages public, private and corporate landowners to provide habitat for songbirds, mammals, amphibians and other native wildlife. Free, downloadable information for home yards and schools is available at the website, as well as lists of native plants, water features and shelter options.
Other speakers Jan. 16 cover modern meadows, easy organic gardening techniques, garden journaling and gardening for birds.
"The overuse of chemical or inorganic fertilizers has serious consequences including the leaching of nitrates into the ground water supply," says Lisa Ziegler of The Gardener's Workshop and cut-flower farm in Newport News. Her workshop topic, "Thinkin' Downstream," helps you learn that what you do in your yard seldom stays in your yard.
"Your actions touch something downstream. Fertilizer run-off into ponds, lakes and streams over stimulates algae growth, suffocating other aquatic plants, invertebrates and fish. Killing weeds along fence rows removes seed-producing plants that host the insects that young animals often depend on to grow."
Heiser says naturalist Doug Tallamy makes the best case in his book, "Bringing Nature Home," about the critical connections between insect and plant communities.
"Insects and plants co-evolved for millennia and have developed intricate inter-relationships," she said.
"Unfortunately, over the past 300-plus years of American history, we've replaced a substantial portion of the natural landscape with non-native plant species from other continents — most notably European and Asian countries — and the result has been an altering of the food web," Heiser said.
"This, in turn, has had the effect of depressing insect populations that depend on specific ecosystem patterns, along with an associated decline in bird populations which rely on insects to feed their young. Although land clearing and development are certainly contributing factors to the loss of habitat, the introduction of non-native species has had an insidious but far-reaching, deleterious outcome."
Habitat gardening, which is more accurately called conservation landscaping, around homes is one way of "putting back," or making an attempt to mimic the original native plant community, she continues.
This means removing exotic invasive plant species like nandina, barberry, butterfly bush, privet, autumn olive, Bradford pear, English ivy, Japanese honeysuckle and periwinkle, and replacing them with their counterpart native species.
"Also, there are other non-native plants that may not be invasive but [are] nevertheless equally useless to insects and other wildlife, such as crepe myrtle, hosta, liriope, boxwood, fescue -- the list goes on and on," she says.
"Responsible habitat gardening includes replacing these species with native plants, too. We have to get away from the idea that 'habitat gardening' is just a cute patch of flowers for butterflies, and that it's OK if the rest of the yard is a mono-cultured acre of turf grass."
To acquaint yourself with habitat gardening, Heiser suggests first going online to look at photos of invasive exotic plants and learn to identify them. Then, take a clipboard and walk your yard, listing any invasive plants.
"When that list is done, make another column of all the other non-natives that aren't invasive but exotic just the same -- you'll probably be surprised that most of your favorite 'ornamentals' are non-native," she said.
"They're called 'ornamental' because they're just that: decorations without any biological purpose."
Next, go back online to find out what native species are best for your growing needs, she advises. This spring, select one non-native plant species in your yard, remove it and replace it with a native species, many of which can be found at local garden centers, as well as at master gardener, native plant society and Virginia Living Museum plant sales.