The excess phosphorus is not used by the plants and may run off
the soil and enter waterways. Soil pH may also increase after
extended additions of organic matter. In subsequent years, we
will alternate between using cover crops and adding organic
matter to help maintain soil fertility.
While the soil at the demonstration gardens is very rich in
organic matter which can help to mitigate the lack of moisture,
this past summer the beds still required regular watering
throughout the extended periods of dryness.
As can be expected, annuals that typically thrive in heat and
drought performed exceptionally well. We grew a number of
ornamental peppers and several were voted as favorites at our
annual field day in August.
Capscium annuum 'Calico' sports strongly variegated purple,
cream and green tri-color foliage. The glossy black fruits are
added bonus, but are extremely hot and not recommended for
Another eye-catching ornamental pepper was Capsicum annuum
'Sangria'. Its well-branched and spreading habit make it ideal
for filling in landscapes and containers. Plants will always
have peppers of both purple and red for a colorful display.
Purple Flash ornamental pepper, Capsicum annuum 'Purple Flash',
produces almost black leaves that are splashed with flashes of
iridescent purple. The plants are topped with small, glossy
black fruits throughout the growing season.
Deer Resistant Plants
The primary focus of the trial gardens is to showcase deer
resistant annuals that perform well in local soils and climate
with minimal maintenance. However, deer browsing in the gardens
was unprecedented this year—especially in South Park. This may
have been due to the drought, as many native plants that deer
typically forage were not available. Instead, they ate annuals
in the gardens that in previous years were untouched such as
globe amaranth, angelonia and lantana.
Salvias continue to be one of the best genera to resist deer
browsing. Salvia farinacea 'Victoria', a mealy-cup sage, is
extremely heat and drought tolerant, long blooming and problem
free. It is attractive to butterflies and pollinators, although
for best bloom, it requires some deadheading throughout the
Also long blooming and heat and drought tolerant is Salvia
guaranitica 'Black and Blue', the anise-scented salvia. The
cobalt blue flowers are attractive to butterflies, hummingbirds
Another standout that was untouched by the deer was Agastache
hybrida 'Arcado Pink', a hyssop with spiky blooms of
pinkish-purple flowers on 20-24” tall plants. With minimal
deadheading, the flowers bloomed the entire summer attracting
butterflies and bees.
Foliage Plants with Impact
A current trend in gardening is the use of foliage plants to
create impact. Incorporating annuals with varying leaf textures
and colors can create spectacular displays. Some recently
introduced fountain grasses are a must-have in the garden.
For several years we have planted Fireworks fountain grass and
once again it did not disappoint. Pennisetum setaceum rubrum
'Fireworks' performs best in a moist, fertile soil. Grown for
its graceful shape and soft seed heads, it can be used en masse
or as a specimen. Fireworks is the first variegated purple
fountain grass. The burgundy mid-vein is flanked by hot pink
Pennisetum glaucum 'Jade Princess' was new to the demonstration
gardens this year and it was a knockout. The plants produced
dense clumps of wide, lime-green foliage with showy burgundy-red
flower spikes. Plants reach 3 to 4 feet in height and look
spectacular used in combination with other warm colors.
Another annual grown primarily for its unique and colorful
foliage is coleus. At one time considered a shade plant, there
are now a number of exciting varieties of coleus for full sun.
Gnash Rambler coleus, Solenostemon scutellarioides 'Gnash
Rambler' with its gorgeous deep purple ruffled leaves was a
Solenostemon hybrida 'Henna', a new variety of coleus grows in
sun or shade and has chartreuse to copper serrated foliage with
dark burgundy undersides.
We used the coleus in the half-moon bed at the end of the
walkway in the North Park garden. The garden was designed with
bright colors—oranges, reds and yellows juxtaposed against
purple flowers and foliage. Although coleus is browsed by deer,
we choose to use the plants and spray them regularly with deer
Mecardonia GoldDust™ packs quite a punch for a diminutive
plant. Tiny, yellow flowers are produced in profusion from May
to frost. The self-cleaning flowers require no deadheading and
spread up to 15 inches making the plant an excellent choice for
use as a groundcover or spilling over the edge of a container.
Zinnias are hands down the favorite annual grown in the
demonstration gardens. By mid-summer the zinnias are in full
bloom and are attracting a myriad of butterflies. One of the
favorites, Zinnia elegans 'Little Lion' offers intense
red-orange double flowers reminiscent of a lion’s mane.
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
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 Extension Demonstration Gardens: Bakerstown Feed & Garden Center, Bedner’s Farm and Greenhouse,
Best Feeds Garden Centers, Eichner’s Farm Market & Greenhouse,
Hahn Nursery and Garden Center, Hess’ Landscape Nursery, Lenix
Greenhouse, LMS Greenhouse & Nursery, Michael Bros. Nursery,
Quality Gardens, Renee’s Garden, Reilly’s Summer Seat Farm,
Soergel’s Garden Center & Orchard, and Trax Farms.
of the Year
flowers for 2006
plant performers from 2006