Plant form and height are important design considerations
for any landscape. Too often, perennial gardens are filled with mounded
forms and daisy-like flowers. Here are a few tall, upright
perennials that
will provide contrast and variation in both texture and height to the other
plants in a bed or border.
Delphinium
- This majestic beauty is associated with the
magnificent gardens of England or the
Pacific Northwest. They will grow here
too but they require a little extra care. Plant them in a site protected
from the wind for best results. They emerge early in the spring, so be
prepared to cover them if frost threatens. During the growing season, tall
types such as the Pacific Giant cultivars may need staking and a shot of extra
fertilizer if leaves begin toturn yellow. Finally, individual plants tend
to be short lived and may need to be replaced after four or five years.
Foxglove - Although there are perennial foxgloves, most
are biennial. The first year from seed, they form a rosette of low growing
leaves only. The second year, they flower, go to seed and die. Self-seeding
keeps new plants coming for future years. Colors of perennial and biennial
types of Digitalis range from pink to yellow. The trumpet flowers are
attractive to hummingbirds too.
Bugbane
- Cimicifuga racemosa is a woodland plant
that bears tall, white spires of flowers in late summer. The foliage grows
to about two feet in height and the flowers may stand up to 6 feet tall.
They prefer a moist, shady location and may be grown as companions to
hosta.
Hardy Lilies -
Daylilies (Hemerocallis species) have
grass-like foliage and survive the winter as a storage root or crown. Each
flower lasts only one day. Hardy lilies (Lilium species - Hardy Lily) such as
the Easter lily, are bulb plants. They have a single, long stem ranging from
18 inches to over 6 feet in height which bears many flowers that last for
weeks. There are many types and colors of flowers with some being extremely
fragrant. Most lilies prefer sunny, well drained sites although the martagon
lily will do fine in the shade.
Cardinal Flower -
Lobelia cardinalis may have
either green or bronze foliage. Brilliant red flowers emerge in summer from
a stem that may reach 4 or 5 feet in height. Cardinal flower enjoys some
shade and a rich, moist soil.
In my garden, I have trouble growing cardinal flowers. It
seems that chipmunks like to climb up the plant and strip off the "skin" of
the stem. Perhaps they like to lick the sweet sap since they do not appear
to eat what they have pulled off.
Gooseneck Loosestrife - Perhaps not as commonly grown as
the other plants, Lysimachia clethroides would make a handsome
addition to any garden. The white flower spikes arch gracefully from the top
of 24 to 36 inch stems. It prefers full sun and a moist soil for best
flowering but will do quite well in partial shade. Allow room for expansion
since this plant will "move" a little by rhizomes beneath the ground but it
is not overly invasive.
Although the name is similar, this plant is no relation to
the pink flowered loosestrife which is clogging many lakes and weriands.
That one is in a different genus named Lythrum.
Astilbe - There are many cultivars of astilbe ranging in
height from 12 inches to 4 feet. Astilbe taquetti, the fall astilbe,
produces a beautiful 3 to 4 foot tall lilac spike. It is good for the back
of the flower bed and, like most astilbes, will do well in either sun or
shade. They are also well adapted to wet sites such as next to a pond or
stream.
Iris
- The tall, bearded iris provide a nice upright form
and beautiful flowers in early summer. Remember that they need excellent
drainage and should not be planted too deep. The
rhizome should be just at
the surface of the soil. Siberian iris is a good alternative for the wet
site.
Gayfeather
- The species Liatris provides several
plants that display a tall, usually purple, spike during the summer. Most
cultivars are 3 to 4 feet tall although the cultivar 'Kobold' seldom exceeds
30 inches. Unlike most other spiked plants, the flowers of Liatris open from the top of the inflorescence downward.
