New Cultural Techniques
This year some new cultural
techniques were incorporated in the gardens. For many years, the
beds were topped with horse manure in the fall which was then
ro-totilled into the beds in the spring. Because the planting beds
have good soil structure and adequate organic matter, we chose not
to rototill this year. One of the main reasons was to reduce the
number of weeds in the planting beds, as disturbing the soil in
spring brings the weed seeds to the surface where conditions are
good for germination. Research also shows that over-cultivation can
destroy the structure of the soil as well as damage earthworms and
other organisms. We hand weeded the beds and lightly turned the
manure into the soil. After planting, a granular organic fertilizer
was broadcast around the plants. No herbicides, insecticides or
fungicides are used. The gardens are planted the first week of June
and the spent annuals removed at the end of the season.
The demonstration gardens focus on
annual flowering plants because they remain the top selling
horticultural crop. Both gardens also include an assortment of
perennial flowers, ornamental grasses, and herbs. Each plant is
labeled with a sign that includes botanical name, common name,
cultural information, and the donor.
Master Gardener Program
Demonstration Garden - North Park
Both gardens are exposed to full sun,
and are open and unfenced. We do spray the daylily bed at North Park
and the pollinator beds at both South and North Park with a deer
repellent called Liquid Fence. We also sprayed a few plants that
were severely damaged right after planting to allow them a chance to
get established (some never did recover). Plants that are damaged
by deer for three consecutive years are not planted again. The deer
population forces us to try new plants every year, while keeping the
tried and true.
The weather this year was cool and
rainy, and those plants that prefer the cooler temperatures thrived
this year. Other annuals which prefer hotter, drier weather never
really reached their full potential. Overall, it was a great year
in the demonstration gardens and we were rewarded with many
outstanding performers that thrived under the care of the Master
Gardeners. Because there were so many annuals that qualified for
the outstanding category, this list includes some of the favorites
of the Master Gardeners who tended them. Plants that are considered
outstanding performers bloomed all summer with minimal deadheading
and had no signs of insect, disease problems or deer damage.
Hands down, one of everyone’s
favorite plants was Angelonia angustifolia, the summer snapdragon
which was superior in both North and South Park gardens.
Angelonia is a tough, vigorous plant that grows well in containers,
as well as beds and borders. The flowers can be white, pink or
shades of blue and purple. Angelonia Angelface® Wedgwood Blue
produces white and blue bicolor flowers. Angelonia is an excellent
cut flower, lasting up to 10 days in a vase.
Another standout at both gardens was
the drought and heat tolerant ornamental pepper. At South Park,
everyone’s favorite choice was Capsicum annuum ‘Sangria’. The
plants have a mounded habit and produce striking purple and red
fruits that are non-pungent. The gardeners at North Park favored
Capiscum annuum ‘Calico’ with its strongly variegated foliage of
purple, cream and green, and its glossy black and red fruits.
One of the most pleasant surprises
was Penstemon ‘Phoenix Red’ with its very large rose-red flowers
that have prominent white throats. The blooms are produced on
upright flower spikes, that do not flop and require minimal
deadheading. Phoenix red penstemon is heat tolerant, and attracts
Penstemon ‘Phoenix Red’
Another surprise was Chrysocephalum
apiculatum ‘Flambe Orange’. The plants were rather weak looking
when they were planted, but they hit the ground running and bloomed
non-stop throughout the summer producing small button-like yellowish
orange flowers all season. Flambe orange strawflowers are heat and
drought tolerant and are ideal in areas where watering is limited.
They have attractive silver gray foliage and perform well as a
cascading plant in a container.
Year after year, one of the most
dramatic plants in the demonstration gardens is castor bean, Ricinus
communis ‘Carmencita Bright Red’ which can reach 10 feet in height,
although ours grew about 6 feet tall. The palmate-shaped
reddish-brown foliage and salmon-pink flowers are very showy;
however, the seeds, leaves and stems are poisonous to humans and
Hibiscus acetosella ‘Haight Asbury’
is grown primarily for its foliage which is a tapestry of colors
ranging from rich burgundy to pink and cream. Once established, the
plants are heat and drought tolerant and perform well in large
containers or in combination with other flowering annuals.
The zinnias in North Park really
stole the show this year. We grew four different varieties which
attracted many bees and pollinators. Zinnia elegans ‘Scarlet
Flame’ grew 4 feet tall and produced scarlet red blooms all season
until frost. Although zinnias are susceptible to powdery mildew
especially in humid conditions, ours were not affected until very
late in the season. Water zinnias by soaking the ground to keep
leaves dry and prevent powdery mildew.
Mexican Hyssop, Agastache mexicanus
‘Acapulco Red’ is a durable, old-fashioned favorite with fragrant
flowers and foliage. The whorled flowers which attract butterflies
and hummingbirds range in color from orange, pink, mauve and
purple. Hyssop is extremely heat and drought tolerant.
If you are looking for a white or
light colored flower for full sun, consider planting gypsy white
yarrow, Achillea ptarmica ‘Gypsy White’. Mounds of delicate pure
white flowers cascade from the fine foliage and are an excellent
choice for containers or the front of a border. Some deadheading
is necessary to remove the spent blooms.
2009 Pollinator Garden
Patina delft ageratum, Ageratum
houstonianum ‘Patina Delft’ is a relatively new introduction with
bi-colored button-like flowers in shades of soft blue and white.
The eye-catching blooms are appropriately named as the flowers are
reminiscent of delft pottery. The new flowers emerge just above the
older flowers and effectively cover the spent blooms thus
eliminating any need for deadheading.
Purple Fountain Grass
Purple Fountain Grass, Pennisetum
setaceum ‘Rubrum’ produces waves of graceful nodding soft purple
plumes that arch up and out from burgundy-tinted foliage. It is
especially dramatic in clusters, mass plantings or along slopes.
Fountain grass is heat and drought tolerant, and attractive in fall
One of the most handsome plants grown
at both gardens was Salvia guaranitica ‘Black and Blue’. The cobalt
blue flowers with their black sepals attract many pollinators
including hummingbirds. Black and blue salvia produces tubers
which can be dug and saved for subsequent years.
Be sure to include some of these
outstanding performers on your shopping list and visit the gardens
next summer to vote for your favorite annual –we want your input in
our evaluations for next year. The North Park Demonstration Garden
is located at the intersection of Babcock Boulevard and Wildwood
Road, at the Veteran's Monument across from North Park Lake. The
South Park Demonstration Garden is located at the intersection of
Corrigan Drive and McConkey Road, just down the road from South
Park’s Wave Pool.
These gardens could not exist without
the support of our partners from Allegheny County's Parks and Public
Works departments. Many thanks to the following local garden
centers that generously donate seeds, plants, fertilizer and mulch
to the Penn State Cooperative Extension Demonstration Gardens: Bedner’s
Farm and Greenhouse, Cecil Twp.; Brenckle’s Farm & Greenhouses,
Pittsburgh; Best Feeds Garden Centers, Gibsonia; Chapon’s Greenhouse
& Supply, Baldwin; Donnan Landscape Services, McMurray; Eichner’s
Farm Market & Greenhouse, Wexford; Englert Nursery & Landscaping,
Bethel Park; Glenshaw Feed & Garden Center, Glenshaw; Hahn Nursery
and Garden Center, North Hills; LMS Greenhouse & Nursery, Allison
Park; McTighe’s Flower & Garden Market, Glenshaw; Meder’s Home &
Garden Center, Pleasant Hills; Quality Gardens, Valencia; Renee’s
Garden, reneesgarden.com; Reilly’s Summer Seat Farm, Ohio Township;
Soergel’s Garden Center & Orchard, Wexford; Trax Farms, Inc.,
Finleyville; The Urban Gardener, Pittsburgh.
Best flowers of
plant of the year
that will not bloom