UT Gardens Plant of the
Month for August 2014:
Cardinal Flower
Submitted by Derrick Stowell, HGTV – UT
Gardens educator
Cardinal flower, also known as Lobelia
cardinalis, is a beautiful native perennial found throughout North America.
It can be an overlooked flower for the landscape, but don’t rule out this great
native. It was first found in wetlands of Canada when European settlers entered
the area in the 1600s. Wild populations of
this plant have been declining as wetlands have been drained and as more land
has been developed for human use.
There
are numerous common names for this plant, including scarlet lobelia and red
lobelia. The bloom, which is usually scarlet, is what really sets this
plant apart from other summer-flowering perennials. A raceme forms a single,
unbranched inflorescence with multiple small flowers attached. The flowers can
range from scarlet to pink or even white. Cardinal
flower grows 3- to 4-feet tall with a spread of about 2 feet. Its vertical
growing habit adds a strong linear component to your garden. Blooms can be
present from early to late summer. In the wild, they begin in late summer
and bloom into fall if moisture is adequate.
Cardinal flower is an excellent choice for a
perennial border or naturalized garden area. It grows best in partial shade and
in moist conditions. However, it can also tolerate full sun in cooler summer
climates. The native varieties are often found growing along streams or other
wet natural areas. Because of its love of moist conditions, it is an excellent
selection for a rain garden. In fact, you can find this plant growing in the
rain garden in the UT Gardens, Knoxville.
If
you are not growing Cardinal flower in a rain garden, you will want to amend
your soil with organic matter such as compost and mulch to help keep soil
moisture levels to its liking.
This
perennial is one of those “plant it and forget it” selections and does not have
any serious pest or disease problems. Cardinal flower can also be propagated by
clump division or seed. Just be sure to be able to identity young shoots so as
not to remove seedlings when weeding. It is cold hardy from Zones 3-9.
There are several cultivars for this plant
including ‘Alba’ with white flowers, ‘Heather Pink’ with pink flowers and a new
introduction called 'Black Truffle' which is sure to stand out with its
dramatic, dark chocolaty-purple foliage and bold red flowers. Superior to other
dark-foliaged Lobelias on the market, 'Black Truffle' holds this deep color
throughout the growing season.
One reason I enjoy this plant is that it produces
nectar for humming birds and butterflies. When it blooms at the UT Gardens, you
can almost always see a humming bird or butterfly flying around getting a
snack. Another plus is that deer tend to leave it alone!
Derrick
Stowell plans and conducts educational programs for the University of Tennessee
Gardens, Knoxville. The UT Gardens
include plant collections located in Knoxville, Jackson and Crossville.
Designated as the official botanical garden for the State of Tennessee, the
collections are part of the University of Tennessee Institute of Agriculture.
Their mission is to foster appreciation, education and stewardship of plants
through garden displays, educational programs and research trials. The gardens
are open during all seasons and free to the public. See utgardens.tennessee.edu for more information.
###
Contact:
Derrick Stowell, UT Gardens, Knoxville, 865-974-7151, dstowell@utk.edu
Patricia McDaniels,
UTIA Marketing and Communications Services, 615-835-4570, pmcdaniels@tennessee.edu