Here are six more of my favorite garden perennials. These plants have all passed through the University of Georgia evaluation program.
They're essential plants for any garden. I chose them for their vigorous growth, garden center appeal and unusually good landscape performance over a range of soils.
You may have to search for the cultivars, but they're all in the market in Georgia.
Chrysanthemum coreanum 'Ryan's Daisy'
The first perennial in the Thomas garden was "Ryan's Daisy." I've added many mums since then. None compares to the original.
Ryan's daisy was discovered by Ryan Gainey, a well- versed garden designer with an incredibly fine sense of color coordination. This specimen has spellbinding pink flowers laced with a pale yellow eye.
It has been used here in Georgia as the mid-planting between Helianthus angustifolius and deep purple, sun-lover coleus cultivars, patched with Salvia leucantha. The yellow, pink, crimson and purple combination is stunning in September, and it goes on into November in south Georgia.
Pink is a rare color in fall gardens, and by itself this plant is a must. It forms wonderful 2- to 3-foot-high mounds. And it's solid color by September.
Pinching in June helps produce a bushy plant. But it doesn't flop-out like other mums. Water and fertilize it often to get fast growth.
Lantana camera 'Miss Huff'
You know you have the real Miss Huff when you see a fast-growing, huge lantana, profuse blooming with extreme tolerance to heat and drought -- and no black seeds. This cultivar is sterile. It's also deer-resistant.
Miss Huff regularly gets to be a 5-foot mound with thousands of flowers in Georgia. Once it starts blooming, it attracts butterflies like a magnet.
The flowers are bright yellow with orange, usually two or four per stem. It needs no pinching, except to control growth.
It grows exclusively in full sun -- the warmer, drier and sandier the soil, the better. It's perennial through Zone 6 if you take three steps.
- Don't cut the frost-killed stems back. Pile up leaves within the mound of branches once they've dried off.
- Don't remove the leaves until May.
- Don't expect new shoots until late May or early June.
It's a slow starter. But once it comes up, stand back.
Gaura lindheimerii (Swirling Butterflies)
This is a relatively new plant to Georgia gardens. A sun-loving perennial, it sends up tall, thin branches with hundreds of pure-white flowers.
This heat- and drought-tolerant plant gets 3 to 4 feet in diameter within two years. It's a great plant for hot, sunny places.
It will rebloom all summer if you cut the old flower stems less than halfway back. Cutting the flower stems close to the main stem caused most of my gauras to die from disease. Once I stopped cutting so far back, my garden was aglow with gauras.
A new cultivar on the market called Siskyiou Pink has pink flowers that cascade rather than stand tall. It looks fantastic in large containers and as a highlight to a perennial border.
Be sure to plant this wonderful genus in fall or within the next few weeks. Gaura does best when it has time to get its roots established.
Dianthus gratianopolitanus 'Bath's Pink'
I've had this plant in my garden since 1990, and I've yet to become tired of it. Every spring it sends up fresh blue-grey-green shoots, followed shortly by scads of pink blossoms. It survives our summer heat and looks spectacular in the fall.
Bath's Pink is a sandy-soil, high-drainage plant. Don't fertilize it heavily or water it often. In summer, be sure to pull debris and cut off any dead flowers or stems to reduce chances of disease.
It's so easy to propagate it's almost embarrassing. You can simply pull 4-inch tufts away from the mother plant and bury half the length of the stems in garden soil.
Kept moist and slightly covered by pine straw, the tufts root quickly and take off. I prefer to propagate them in early fall, or late spring, several weeks after the blooms are gone.
Physostegia virginiana 'Vivid'
"Obedient plant" flowers in mid- to late summer, with white cultivars flowering earlier than pink ones. Tubular flowers, arranged in rows on the spike, remain in place when pushed aside -- hence the name.
It's easy to grow in most of Georgia and prefers moist soil. Plants grow 18 to 30 inches tall. Put them 15 to 18 inches apart in full sun. In southern Georgia, they may benefit from late-afternoon shade.
I just love the cultivar called "Vivid." It has bright pink flowers. It's shorter, less aggressive and flowers much more abundantly than the others.
I must tell you, this plant is anything but obedient. It grows more like a Sherman tank. Physostegia is good for large areas you want to cover with a tall, low-maintenance plant.
One plant can fill in 3 square feet in one year. For a spot of sunshine where nothing else will grow, here's a beautiful solution.
Hosta sieboldiana 'Patriot'
Hostas are the No. 1 perennial in the country. And they should be. You can't kill them, they look great and they're real easy to propagate.
Hundreds of cultivars cover a range of colors, shapes and sizes. Leaves may be smooth, ribbed, seersuckered, flat, wavy or twisted. Colors include light green, dark green, gray or bluish-green.
As a bonus, it has lily-like flowers on stalks above the 1- to 3-foot foliage during the summer. There is a hosta for everyone.
My pick? "Patriot" is the finest cultivar I've ever grown. Clean, bright, white borders on dark green leaves make a stunning garden display. It's worth looking for.
Hostas are great for shaded areas with moist, rich soils. However, certain varieties need some sun to get proper foliage color. Plant them 24 to 36 inches apart, depending on the variety.
One word of warning -- deer love this plant more than life itself.
(Paul Thomas is a horticulturist with the University of Georgia College of Agricultural and Environmental Sciences.)