How Does Your Garden Grow?
Experts recommend sustainable practices to overcome environmental challenges
Chemicals, invasive plant and insect life
and the weather have created havoc in
So on Sept. 21, as summer gave way to
fall and gardeners began planning for the
next growing season, a landscape architect, a
botanical garden curator, a water utility
executive, a garden store owner and a
county extension agent gathered at UNC
to share ecology-sensitive strategies.
“Greening Our Gardens: Sustainable
Gardening in Challenging Times” was
offered by the GAA’s Carolina College of
Peter S. White, director of the N.C.
Botanical Garden, introduced panel members and set the tone. “Our gardens are on
the front lines,” he said. “They are important to North Carolina’s economy.”
Drought, hurricanes and climate change
have taken their toll. North Carolina’s hardiness zone, an 11-level rating of temperature
zones ranging from vulnerable to frost year-round (Zone 1) to frost-free year-round
(Zone 11), has risen a half level since 1990
due to climate change. Gardeners have tried
xerescaping, planting drought-resistant plants;
ecoscaping, landscaping to make the least
impact on the environment; and zeroscaping,
using plants already present in their gardens.
“We can’t afford to run out of water,” said
Gary Feller, public affairs administrator at
the Orange Water and Sewer Authority, who
discussed the practical economics of water
conservation. To encourage conservation,
OWASA is increasing its block water rates.
Customers using 2,000 gallons a month or
less are charged a lower rate; as they move
up through incremental blocks, they are
charged increasingly higher rates.
Feller touted low-flow toilets as a way to
conserve, as nearly a third of the water residential customers use is attributed to toilet
flushes. Washing clothes accounts for about
a quarter of residential use, with bathing
close behind. OWASA is exploring water
re-use for toilets and outdoor watering.
Landscape architect David Swanson talked
about challenges he encountered in landscaping Quail Hill, the UNC chancellor’s
residence off Raleigh Road. The property
sits in the clay soil of the Triassic Basin.
Rather than seep through layers of dirt,
water pools in the space around the plant’s
roots, and the plant drowns. Swanson used a
slide show to demonstrate how, by digging
swales 3 to 5 inches deep and building low
mounds of soil, leaves and mulch, a gardener
can shunt runoff water to a collection pool
At Quail Hill, Swanson yanked all of the
ivy that had grown as groundcover in a
shady area among trees. That gave native
woodland plants a chance to sprout. He also
recommended pulling out exotic invasive
plants before they staked their territory. He
left the audience with 12 tips on becoming a sustainable gardener. (See accompanying
Chris Liloia, habitat curator at the N.C.
Botanical Garden, made the case for landscaping with native plants: Already adapted to
local plant pathogens, soil, water and insects,
they don’t require chemical pesticides and
herbicides to thrive. She also pointed out the
link between the butterflies people enjoy in
their garden and the caterpillars they don’t.
“A few chewed leaves is a small price to
pay for a new generation of swallowtails in
the spring,” Liloia said.
Ashley Mattison ’ 89, co-owner with her
husband of Fifth Season Gardening Co.,
urged gardeners to “work with your dirt.”
“Make it the best it can be,” Mattison
said, and told how to make plants happy
with natural alternatives to synthetic pesticides, herbicides and fertilizers.
Avoid fertilizers with high nitrogen
counts (the first of the three numbers on a
fertilizer bag). Plants can’t absorb that much
nitrogen, and it ends up in runoff, creating
oxygen-choking algae blooms downstream.
Try worm castings instead, she said. Bone
meal increases flowering, and alfalfa meal
and blood meal prevent flowering. Ward off
deer by planting rosemary in perennial
beds. Kill weeds with clove oil. Squelch
dandelions and crabgrass with corn gluten.
“Ten years ago, it was hard to find
organic products,” she said. Now, garden
stores are well-stocked.
Al Cooke, an extension agent for
Chatham County, underscored the importance of nurturing the soil. “Most gardens
were once construction sites,” Cooke said.
“You can’t put the burden to thrive on the
plants. We must be good gardeners.”
His advice was practical. Dig a hole big
enough for you and the plant to stand in.
Plant grass where you’ll use it, not in a narrow strip between the curb and flowerbed.
Irrigate efficiently with “gater bags,” water-filled plastic bags with tiny holes that drip
water onto root aprons. Make sure timed
irrigation systems shut off when it rains.
Once you start pruning, stop fertilizing. The
plant doesn’t need extra nutrients anymore.
At the end of the two-hour session,
audience members asked questions and
shared their experiences. Steve Jenks ’ 93
(PhD) recently moved into a new community that is already overrun with crabgrass
and little else. He left the seminar with
ways to deal with the landscape sustainably.
“There is so much information available,
sometimes it is overwhelming,” Jenks said.
His neighbor, Rhonda Goolsby, felt reaffirmed.
“It’s encouraging to me that I know
more about sustainability than I thought,”
Goolsby said. ■
— Nancy Oates
12 tips for sustain ability:
■ Mulch regularly.
■ Specify products that
require low amounts of
energy to be manufactured
(also called low-embodied-energy
products) and use local suppliers.
■ Shade paved areas.
■ Minimize impervious surfaces.
■ Reduce the lawn area.
■ Increase biodiversity by using a
variety of plants.
■ Use local, natural plant communities
■ Protect soil from compaction.
■ Avoid synthetic, quick-release fertilizers.
■ Designate areas to reuse plant debris
■ Capture and treat stormwater on site.