A garden in a years time has its ups and downs. Spring is usually the showiest time of the year, particularly for the gardener with lots of summer shade. Over the years I have come to rely on a few favorite perennials to carry the garden past the bloom times of many others. As showy blossoms open and fade, these few favorite structure plants bide their time, filling space and handling the passage of time with style.

As I'm sure many of you have noticed, some of the most beautiful flowering perennials look pretty tired once flowers have passed. The job of pollination is finished, no need to remain attractive. The structure plants, on the other hand, are not always grown for flowers and they are not necessarily the plants you visit the nursery to buy, but they are the very plants you should own.

Listed below are my favorites with a brief description of each. They earn their keep.

Sun Perennials

Amsonia hubrictii
This is a handsome native perennial with small, pale blue flowers in spring. The foliage is clean, flowing and lovely, persistent through summer and fall, turning a rich yellow in fall. Plants may reach 4 feet in height but usually stand closer to 3 feet. Drought tolerant.

Calamagrostis 'Overdam'
An ornamental grass that is also a native with stiffly variegated leaf blades and pencil thin plumes which arrive early (June) and hold on until fall. Drought tolerant, deer proof.

Calamagrostis 'Karl Foerster'
The all blue-green bladed form of Calamagrostis with thin reddish bronze plumes during the summer. Drought tolerant, deer proof.

Euphorbia amygdaloides var. robbiae
Wonderful deep, rich, evergreen foliage that resembles the houseplant pittosporum. Chartreuse flower heads rise up in spring to about 24 inches. Seemingly at home in sun or shade, I grow this plant on the north side of my house, just outside of my office door where it recieves no direct sun. Staged with tassel fern or Polystichum polyblepharum and Helleborus foetidus, my patch is green year-round. Deer proof and drought tolerant.

Kalimeris mongolica or pinnatifi da
Small double composite flowers are held on thin but stiff stems that rise to 3 feet. Incredible bloom period, running from late June to frost. I experimented with plants this year and cut them back to 4 inches in late summer, the resulting growth produced new flowers and is still flowering. A very tidy plant that handles the space between other plants remarkably well. A Georgia Gold Medal winner.

Panicum virgatum 'Heavy Metal'
There have been many improved forms of Panicum virgatum, all are worth purchasing for their great blue-green foliage and the fact that they are native. Plumes arrive in early August and they are wispy, filling gaps in the garden in a delightful airy way. Plant with Lilium speciosum 'Rubrum', rudbeckia and anything else that flowers from August to fall. Deer proof, drought tolerant.

Stachys 'Big Ears' aka 'Countess Helen Von Stein'
The improved lamb's ears that produces large, very long leaves of soft velvet that resist the effects of high humidity and temperatures. Not your grandmothers lamb's ears! Handsome well into winter! Deer proof, drought tolerant.

Calamintha nepeta
A small, very showy summer flowering perennial that seems to look better as summer months progress. Forming a round, low mound with dainty white flowers that attract many nectar seekers. Deer proof and drought tolerant.

Shade Perennials

Carex siderosticha
Resembling a hosta with its wide leaf blades, this ornamental grass is one of very few that prefers shade. Each leaf is green with contrasting white bands.

Hakonechloa macra 'Aureola'
Another ornamental grass that prefers some shade. The foliage is bright yellow with fine green stripes and a lax habit, gracefully arching to all sides. Very slower to grow but well worth the wait, a classic beauty.

Heuchera (leaf types i.e. americana, micrantha, villosa)
Most ornamental coral bells are semi-evergreen, which is essential in the shade garden where so many perennials are soundly deciduous. The plum and purple leafed varieties are beautiful next to blue hostas.

Helleborus
Two come to mind immediately as absolutely essential plants for the shade gardener, Helleborus foetidus and orientalis. The former is short lived, expect 4 to 5 years from each plant but copious seed is produced and volunteers always follow. Helleborus foetidus has also been very happy in sun for me so consider it for both locations. The flowers are green, blooming in late winter on handsome, evergreen plants. The latter is long lived with flowers of soft pastel shades in late winter and early spring that seem to persist for months. Deer proof, drought tolerant.

Polygonatum odoratum 'Variegatum'
Solomon's seal is a very handsome plant with arching stems and lightly variegated foliage. Plants may take a few years to mature, becoming handsome in time, the envy of all! Drought tolerant.

Smilacina racemosa
False solomon's seal emerges in spring with gracefully arching stems that carry white flower clusters at the tips of each stem. Late summer finds the tips of stems weighted down with red berries. The foliage is medium green. Drought tolerant and tough.

Rhodea japonica
A little known plant with thick, almost succulent leaves that boldly arch from a central crown. Very slow to grow and not necessarily handsome year-round when placed in a windy north-west corner where winter winds will take a toll on otherwise handsome foliage. Plant in a protected eastern corner and you will appreciate the green leaves all year.