- Use
- Selection
- Bed Preparation
- Planting
- Care and Maintenance
- Division and Propagation
- Diseases and Insects
- Recommended Perennials
- Additional Perennials
- Quick Reference to Common Perennials
Plants are classed according to their growth cycle as annuals, biennials or perennials. Annuals are short-lived plants that complete their entire life cycle within one growing season. Biennials normally do not bloom until the second season, form seeds and then die. Perennials live from year to year, with varying bloom times.
Perennials are also classed as woody (trees and shrubs that produce woody above-ground stems and branches that live from year to year) or herbaceous (plants that produce comparatively soft tissues which often die back to ground level at the end of the growing season). Herbaceous perennials persist by means of various underground storage structures—bulbs, corms, tubers, tuberous stems, tuberous roots and crowns.
The distinction between annuals and perennials, woody and herbaceous, is not always sharply defined because climate influences growth potential. Further, those biennials and perennials that bloom the first year along with tender perennials (those actually killed by frost) are often treated as annuals in the landscape.
This publication is devoted specifically to herbaceous perennials (subsequently referred to simply as perennials), primarily to those that persist from crowns and/or fleshy roots. For information on bulbous-type herbaceous perennials (daffodil, canna, dahlia, etc.), refer to Extension bulletin 918, Flowering Bulbs for Georgia Gardens.
Use
There has been a resurgence of interest in perennials. Home gardeners are becoming more aware of perennials and so are commercial landscapers.
Because perennials live from year to year, they offer a certain permanency to the landscape. They are virtually unequaled in providing year-round color and interest; variations in colors, sizes, habits and time of bloom are almost endless. Although many gardens and garden borders feature perennials exclusively—the classic English perennial border is legend—most often their best use comes in the skillful combination with other plants in the total landscape.
Some sources have suggested that perennials are not well suited to the Southeast. This simply is not true. Many perennials perform exceedingly well in Georgia and the Southeast in general. Not all perennials perform well here, but then not all perennials perform well in the Northeast or even in England. Remember, much of the existing literature regarding perennials is based on conditions where cooler summer climates prevail. So exercise care in choosing plants well adapted for your particular area.
Most perennials are completely winter hardy, although there are a few so-called tender perennials that are sometimes injured by low temperatures. The limiting factors in perennial adaptability in the Southeast are often heat tolerance and diseases that prevail in hot, humid climates.
Selection
In addition to climatic adaptation, perennials should be selected based on their ability to perform well and contribute to specific landscape needs. Height, spread, color, time and length of bloom, and plant habit should be given careful consideration. Some perennials are tolerant of poor drainage, others totally intolerant. Sun and shade tolerance varies. All these factors are important in selecting and using perennials correctly.
In most cases, a given species has many varieties available, which greatly extends the size and/or color range of the species. Commercial catalogs are a good source of information on varieties. Purchasing plants by botanical name and variety is a good idea because common names vary from region to region.
Bed Preparation
Good bed preparation is extremely important for perennials. Remember that you are making a long-term planting; it is much easier and much less disruptive to improve the soil and correct drainage problems before planting.
Beds should be deeply spaded, to a depth of at least 8 to 10 inches if possible. Many perennials are deep-rooted. Some perennials grow well in sandy soils, but most prefer soils higher in organic matter and with better water-holding capacity. Heavy clay soils should be amended with sand, perlite or coarse bark to improve drainage. Good drainage is critical to the success of many perennials. To test for drainage, dig a hole about 10 inches deep and fill with water. The next day, fill the hole again and see how long the water remains in the hole; if it drains away in eight to 10 hours or less, drainage is satisfactory for most perennials. In some situations, it may be necessary to install underground drainage lines or construct raised beds.
Have the . A pH of 6.0 to 6.5 is optimal for most perennials. Most Georgia soils are acid and require the addition of lime to correct pH. In the absence of a , add a complete fertilizer such as 8-8-8 or 10-10-10 at the rate of a 1½ pounds per 100 square feet. Incorporate the fertilizer and lime, and rake the soil surface smooth.
Planting
Many perennials can be seed propagated, but most home gardeners prefer to start with established plants. Most perennials can be planted in fall or early spring. Many perennials are now produced in containers, which aid in transplanting and establishment, but many are still field grown and shipped bare root and dormant. Fall planting is often better because it gives the plant more time to become established before the start of active growth.
Unless instructed otherwise, position the crown of the plant at or just below the soil surface. Planting depth is critical; if the crown is planted too deeply, it may develop crown rot. Untangle and spread the roots. Fill the planting hole with soil, gently firm it around the roots and water thoroughly. You may want to mark or protect the plants, since when dormant they may be forgotten or stepped on accidentally.
Care and Maintenance
It is a misconception that because perennials last from year to year they require little maintenance and care. While some perennials survive with little care, more require some attention to look their best. In many cases perennial beds require more work than annual beds, which can be completely renovated rather easily each year. But the rewards of perennials make the added maintenance worthwhile.
Perennials vary in their drought tolerance, but more require an ample moisture supply at least during periods of active growth. Do not rely on normal rainfall; irrigate if necessary. Allow the water to penetrate deeply. Frequent light waterings are not advisable because they wet only the upper soil depths and result in shallow root growth and wet foliage and flowers, an invitation to many diseases. Soaker hoses and drip irrigation systems work well with perennials.
Mulching helps conserve moisture, control weeds and improve the overall appearance of the garden. Mulches also tend to prevent soil crusting, which retards water penetration, and prevent soil from splashing on lower leaves and flowers. Mulches also provide an added degree of winter protection. A word of caution: Heavy mulches that hold moisture can be detrimental, particularly to plants subject to crown rot. Pine bark, pine straw, wood chips and a variety of other materials are used successfully.
Maintenance fertilization is essential to the continued growth of perennials. An application of 8-8-8 or 10-10-10 (1½ pounds per 100 square feet) should be applied in early spring and once or twice again during the growing season. Maintenance fertilization practices should be based on ; application of phosphorus is frequently unnecessary once adequate soil levels become established. Water the bed after application so that the fertilizer enters the soil and is available to the plant. Wash any fertilizer off the foliage to prevent fertilizer burn.
A well-prepared bed requires little cultivation. Deep cultivation is likely to injure roots and often uncovers weed seeds, which can then germinate. Weed control should usually be done by hand weeding or with the use of herbicides. Exercise extreme caution when using a herbicide. Very few are suitable for use around perennials. Read the label carefully to be sure it will not injure desirable plants.
Figure 1. Tie the plant securely to the stake but not so tight as to cause girdling.Many perennials are top heavy and require support to prevent them from bending or falling over during wind and rain. A number of methods can be used to lend support, but simple wire, plastic or bamboo stakes are often the easiest. Done correctly, the plants grow to cover the stakes so that they need not detract from the appearance of the plant. Be careful not to twist the ties too tightly because girdling may result.
To maintain vigorous growth, remove mature flowers; do not allow seeds to form. Removal will often stimulate growth of side shoots on which additional flowers will form.
Remove dead foliage and stems in the fall. Remember that it is natural for the tops of many perennials to be killed to the ground by frost. Some herbaceous perennials have evergreen foliage.
Division and Propagation
While the length of time varies, most perennials eventually become overcrowded and require division. Mature clumps can be cut or pulled apart. Divisions should usually contain three to five shoots or growing points. Discard any weak or diseased divisions. The time to divide perennials varies somewhat, but is most often fall or early spring, coinciding with desired planting dates. Many perennials are easily propagated in this way.
Figure 2. Perennials like daylily and liriope, which cannot be pulled apart easily, may be cut or pried apart.
Figure 3. Plants like bearded iris are easily propagated by cutting through the rhizome, leaving at least one growing point on each section.
Many perennials can also be propagated by stem cuttings; garden phlox is a good example. Cuttings should be 3 to 6 inches long. Strip the lower foliage and insert the cuttings into the rooting medium. Cuttings should be protected against drying (a plastic tent or large glass jar works well) until roots form, at which time they can be transplanted to pots or beds. Most such cuttings are taken in late spring or early summer to allow plenty of time for rooting and establishment before cold weather.
Some perennials can be propagated from root cuttings, which are taken when the plant is dormant. Oriental poppy is an example.
Many perennials can also be seed propagated. In many cases, however, vegetation propagation is preferred because the desirable characteristics of the parent plant are retained in the new plants. Some variation is to be expected in seed propagated plants; resulting seedlings can be inferior to parent plants.
Seed propagation techniques are essentially like those used with annuals. Seeds of many perennials, however, do have special requirements, often a need for chilling, before germination can occur. Be sure you know these specific requirements before attempting to propagate perennials by seeds.
Diseases and Insects
No plant is completely immune to insects and diseases; perennials are no exception. A wide spectrum of insects and diseases can attack perennials and may require control measures. Quite often, proper site selection and good cultural practices will prevent many disease problems.
For the identification and recommended control of specific insect and disease pests, consult your county Extension agent.
Recommended Perennials
The following is a list of commonly grown perennials satisfactory for most areas of Georgia. It is by no means comprehensive—many other lesser-known perennials also grow well. The plants are listed alphabetically by common name with additional common names in parentheses.
Achillea millefolium (common yarrow)
A filipendulina (fernleaf yarrow)
Yarrow blooms from mid- to late summer. Common yarrow grows 2 to 3 feet tall, while fernleaf yarrow may grow to 4 feet. Both are easily grown in sunny locations. Colors range from white to pink to red in common yarrow; fernleaf yarrows are yellow or gold. Both dry well. Several other species and hybrids are also available.
Ajuga reptans (bugleflower)
Generally used as an evergreen ground cover, ajuga is a spreading perennial only a few inches tall. It grows well in moist, shady areas. It will tolerate sun if adequate moisture is provided. Attractive blue flower spikes cover the plants in mid-spring. Several varieties are available with pink and white flowers and some with variegated or bronze foliage.
Alyssum and candytuftAurinia saxatile (gold alyssum)
Gold alyssum is frequently used in rock gardens and for edging. In early spring it blooms, producing a dense mat of yellow flowers 9 to 12 inches high. Full sun and excellent drainage are essential.
Anemone x hybrida (Japanese anemone)
Unlike the tuberous, spring-flowering anemones, Japanese anemone flowers later on tall, wiry stems to 3 feet in height. Single and semi-double flowers range from white to deep pink. Moist, rich soils are best. Other species are also available.
Artemisia schmidtiana 'Silver Mound' (silver mound artemisia)
A. ludoviciana 'Silver King' (silver king artemisia)
These two varieties are perhaps the best known of the artemisias, most of which are grown for their silvery gray foliage. 'Silver Mound' is dwarf and compact, about 1 foot in height; 'Silver King' may grow 2 to 3½ feet tall.
Asclepias tuberosa (butterfly weed, chigger weed)
Asclepias is native to Georgia and easy to grow. It prefers full sun and is tolerant of poor soils and drought once established. The familiar orange flowers are produced on plants 1 to 2 feet tall. Established plants do not transplant well.
Aster species and hybrids
Numerous species and varieties of asters are cultivated. Blooming from late summer to fall, height ranges from 1 to 5 feet. Almost all colors are represented. Many are so vigorous they require restraint. The Michaelmas daisies (A. novae-belgii) are common and easy to grow. A. X frikartii, a lavender-blue, flowers from June until frost. Mildew is a common problem with asters, but can be controlled.
Astilbe japonica and hybrids (false spirea)
Astilbe grows 1 to 3 feet high, producing clumps of fernlike foliage and feathery flower spikes. A variety of colors are available as a result of aggressive plant breeding and selection programs in recent years. The plant grows best in shade to partial shade and prefers moist, rich soils.
Baptisia australis (blue indigo)
A member of the pea family, baptisia is adapted to poorer, low-fertility soils. A single clump spreads about 3 feet and grows 4 to 6 feet tall. It is a good substitute for lupine in the South.
Growing to about 12 inches, it is best in shady flowerbeds. The species is pink, but a white variety is available. The plant can be propagated from bulbils that develop in the axils of leaves. This plant should not be confused with the wax begonias and tuberous begonias, which are not hardy in Georgia.
Known for its ability to attract butterflies, this hardy woody perennial now comes in many colors. Plants grow to 6 feet wide and 5 feet tall, require some pruning and require full sun. The cultivar 'Black Knight' is one of the most popular for beginners due to its dark lilaclike flower clusters and wonderful fragrance.
Candytuft is frequently used in rock gardens, for edging and as a ground cover. Growing to a height of 10 to 12 inches, it produces a mass of white flowers in late spring. It is best in full sun, but will tolerate light shade, and is fairly drought tolerant once established. Do not confuse perennial candytuft with annual candytuft.
This is the same species as the florist's carnation. Garden varieties are selected for dwarf compact habits; most of them grow to a height of about 12 inches. Many colors are available. Carnation is very fragrant and an excellent garden cut flower.
This plant makes a 4-foot mound of light blue flowers late July through September. Excellent for cut flowers or for attracting butterflies. The semi-woody plant may die back to the base in cold winters. Caryopteris requires full sun and good drainage; tolerates drought well.
Blue flowers about 2 inches in diameter are held erect 12 inches or more above the basal foliage. Blooming in early summer, full sun and light soils are best. Do not confuse C. Montana with C. cyanus (cornflower, bachelor's button), an annual that grows wild in Georgia.
This plant is a low-growing perennial ground cover for full sun. The dime-size flowers are the deepest blue imaginable and provide color from July through September and beyond. It spreads by runners and does well in poor soils once established. This plant has few pests.
Garden chrysanthemums perform well in all parts of Georgia, although not all varieties are cold hardy. Many colors and varieties are available. The shorter cushio types, ranging in height from 1 to 3 feet, are generally preferred for landscape use. Taller types usually require staking. C. coccineum (painted daisy) grows well in most parts of the state, as does C. X superbum (Shasta daisy). C. zawadskii (C. X rubellum) cv. Clara Curtis, a pink daisy type, is also common in the fall landscape.
Growing 2 to 3 feet tall, they are often used in borders and for cut flowers. Columbine blooms in late spring or early summer. It needs a fairly rich and well-drained soil, and will grow in sun or partial shade. The foliage frequently declines in midsummer. Plants are usually seed propagated but can be carefully divided in August or September. Leaf miner is a common pest.
C. lanceolata
C. verticillata (threadleaf coreopsis)
Coreopsis grows from 1 to 3 feet high and bloom from May to fall if the old flowers are removed. It grows best in full sun and is fairly drought tolerant. Coreopsis is often treated as a biennial. Yellow and gold predominate in the flower color range. Coreopsis is among the easiest perennials to grow.
Low growing and spreading, chrysogonum forms a dense ground cover. Small yellow flowers are produced over a period of several weeks from spring to early summer. Chrysogonum is tolerant of a range of cultural conditions but seems to grow best in moist soils and under light shade.
The larkspur types grow well, acting as reseeding annuals. The delicate airy spikes, in a wide range of colors, are attractive in perennial borders and make good cut flowers. The stately D. elatum types, which grow to 4 or 5 feet, are exquisite but seldom perform well in Georgia and are not recommended. Consolida ambigua (rocket larkspur) is a hardy annual producing blue spikes 2 to 4 feet tall.
DianthusPinks are widely used in beds, borders, rock gardens, for edging and as cut flowers. Growing about 12 inches high, their blooms usually peak in late spring or early summer. Rose, pink and white predominate in the flower color range. The gray foliage is attractive and evergreen. D. deltoides, a low mat-forming plant, also performs well. Some varieties of D. chinensis (China pinks, annual pinks) perform as short-lived perennials in parts of the state.
Growing 1 to 3 feet tall and producing fine-textured foliage, bleeding hearts are useful in shady beds and borders. Most varieties are rosy-red in color; white varieties are also available. D. exima (wild bleeding heart) is native to Georgia.
Very useful for their tall spiky effect, foxgloves may grow 4 to 6 feet tall. They grow best in full sun but will tolerate light shade. Some foxgloves will flower the first year from seed and are treated as annuals. D. purpurea is a self-seeding biennial that remains in the garden much like hollyhock. D. X mertonensis is a true perennial with beautiful strawberry-red flowers. D. lutea also performs as a true perennial.
Gaillardia grows 12 to 30 inches high and blooms from midsummer until frost. It grows easily, prefers full sun, tolerates poor soils and needs good drainage. Yellow, red and orange varieties are available.
An interesting white-flowered perennial, gaura does best in hot, dry, full-sun locations. The thin, titanium-white flowers are borne on long, leafy stalks. The plants can get to 3 feet in diameter and become more attractive with each new season. Young plants may need staking and one mid-season cutback if grown in areas with less than six hours of full sun.
Goldenrod may be disdained by many who consider it little more than a weed, but a number of hybrids may help change that image. The hybrids are excellent border plants that provide a brilliant array of golden yellow blooms from late summer to fall. The widespread adaptability of the species is testimony to its hardiness and vigor.
The perennial type grows 2 to 4 feet high and is useful in beds and borders. It is also used as a cut flower and as a dried flower. Gypsophila blooms from early summer to early fall. It forms a spreading mass, so allow plenty of room.
Hardy ageratum flowers in late summer and fall, producing stems 1 to 2 feet tall with bluish-purple flowers that closely resemble the flowers of true ageratum. A white form also is available. The plant spreads rapidly and has naturalized in many parts of Georgia. It can be invasive and should be planted where it can be controlled.
A strong and vigorous grower, helianthus may grow 5 to 8 feet or more in height. Fall flowering, this plant can't be missed in the border! Allow plenty of room for it.
Christmas rose is valued because of its unique time of bloom: November to early spring. As the name implies, it is frequently in flower at Christmas. Growing 12 to 15 inches high, the flowers are white with pink shading; they are good cut flowers. The foliage is coarse-textured and a useful accent. Helleborus grow best in Georgia in shade or partial shade. A relative, H. orientalis (Lenten rose) is also cultivated; it flowers in mid- to late spring, producing purple flowers with white shading.
HemerocallisDaylilies are without doubt among the most widely grown perennials in Georgia. Growing from 1 to 4 feet high, a rainbow of colors is now available. Bloom usually peaks in June or July, but varieties are available that flower from May until October. Daylilies are easily grown and have much to recommend them.
Coral bells produce a rosette of foliage about 6 to 12 inches high, out of which tall airy flower spikes appear in late spring to early summer. Colors range from the familiar coral to pink, white and chartreuse. Propagated by seeds or division, the foliage is attractive and usually evergreen.
Growing 3 to 8 feet tall, the plants produce flowers 6 to 12 inches in diameter in shades of white, pink, rose and red. Blooming from early summer to fall, it is somewhat coarse in appearance but can be used to advantage in the landscape. Do not confuse it with H. syriacus (althea), a woody deciduous shrub common in the landscape, or with the tropical hibiscus (H. rosa-sinensis), which are not hardy in Georgia.
Growing 4 to 8 feet high, hollyhocks are an old garden standard, particularly useful for background screening or where vertical accent is desired. They grow best in full sun in deep, rich, well-drained soils. Some varieties act as reseeding biennials. Annual types are available that flower the first year. Many colors are available, from pastels to near black.
While hostas do flower (tall spikes with white to lavender flowers), they are grown principally for their rich luxuriant foliage. Clumplike mounds, a few inches to several feet in height and spread, add accent and are occasionally used in mass. Foliage colors range from yellow-green to dark green to blue-green; many variegated varieties are also available.
Siberian irisI. siberica (Siberian iris)
I. kaempferi (Japanese iris)
Blooming in the order listed, irises range from 2 to 4 feet tall with the flower held high above the foliage. An almost endless array of colors is available in the bearded irises, fewer in the Siberian irises, and primarily blues and purples in the Japanese irises. The bearded irises should be grown in full sun and require excellent drainage; the Siberian and Japanese irises grow well in light shade and tolerate moist soils well. Iris tectorum (Japanese roof iris) is a tough iris adapted to a wide range of landscape conditions. Several bulbous iris species also grow well in Georgia.
This selection of lantana is apparently hardy in Georgia. This plant can grow to 7-foot mounds with spectacular flower displays from June to October. A good butterfly attractor and very pest and disease resistant, the plant dies back to its roots and emerges in very late spring or early summer about the time one is convinced it is dead. This plant does best in full sun and is drought resistant once established.
Liatris scariosa (tall gayfeather)
L. pycnostachya (Kansas gayfeather)
L. spicata
Liatris blooms summer to fall and produces tall flower spikes 2 to 6 feet high. Colors range from rose-lavender to pink. They grow best in full sun and are very heat tolerant. Several species are native to Georgia.
L. spicata (creeping lilyturf)
Liriope is generally used as a ground cover, the variegated varieties widely used in landscaping. Many are well suited for border and accent purposes in the perennial garden. Although they are grown principally for their evergreen foliage (1 to 2 feet tall), the white, blue or purple flower spikes produced in late summer are also attractive.
Lobelia cardinalis (cardinal flower)
L. siphilitica (blue cardinal flower)
Cardinal flower is a prized wildflower well adapted to perennial borders. Tall, brilliant red flower spikes may reach 3 feet under good conditions. This species is short-lived but reseeds. Moist soil is a must. Blue cardinal flower is similar in habit but less demanding culturally.
Monarda blooms all summer; colors range from white to rose-pink to wine-red. Most varieties grow 2 to 3 feet high. Monarda is an old garden favorite still worth growing. Mildew is common on monarda.
O. jaburan (snakebeard)
Both are used principally as evergreen ground covers. Mondograss forms a thick dense mat of grasslike foliage 6 to 8 inches high; snakebeard grows to a height of about 2 feet. The variegated varieties of snakebeard are often confused with the variegated liriopes.
Growing to a height of 6 to 8 inches, pachysandra is also used primarily as a ground cover. It flowers but is grown principally for its yellowish-green evergreen foliage. It is best in shade. Several variegated varieties are available.
Pampas grass is probably the best known of all the ornamental grasses. Large fluffy white or rose plumes are produced in late summer on 5- to 10-foot plants. Plants grow best in full sun but will tolerate light shade. Many other lesser-known ornamental grasses also grow well in Georgia.
Peonies are handsome plants in the perennial border. Large showy flowers are produced on plants 3 to 4 feet high in mid- to late spring. Many colors and flower forms are available. The early blooming varieties reportedly perform better in Georgia. Peonies are marginal in central Georgia and not generally recommended for South Georgia. P. suffruticosa (tree peony) is not recommended except in northern Georgia.
Garden phloxP. subulata (moss phlox, thrift)
P. divaricata (blue phlox)
P. carolina 'Miss Lingard'
A very diverse genus, phlox is used extensively. Garden phlox produces tall and showy flower clusters in summer; many colors are available. Moss phlox is used as a ground cover or for edging. It is very heat and drought tolerant but very intolerant of poor drainage. Many colors are available in addition to the common magenta. Blue phlox is one of the few phlox that will grow in shade. It produces a light blue flower. In shade, blue phlox is loose and open; in sun, more dense and compact.
Physostegia is one of the more adaptable perennials growing well in full sun or partial shade and in wet or dry soils. Blooming from mid- to late summer, colors range from white to pink, rose-pink and red. Heights range from 1½ to 7 feet. It is excellent for background use and for naturalizing. Some varieties are so vigorous as to become invasive.
Oriental poppies are spectacular in the landscape. Four- to 6-inch flowers are produced on plants that average about 3 feet in height and spread. Colors range from white to pink, coral and vivid orange and red. Oriental poppies are marginal in Georgia and better suited to northern portions of the state. They should be grown in full sun.
Easy to grow, purple coneflower grows to a height of 3 to 5 feet. Purple petals (ray flowers) surround black centers (disks flowers). A white variety is also available. Mildew is common on purple coneflower.
Rudbeckia is among the easiest of perennials to grow and is naturalized in many areas of the state. Most cultivated varieties grow 2 to 3 feet high and bloom early summer to fall. Orange, gold, yellow and brown colors predominate. Double-flowered varieties are available. Mildew is common on rudbeckia.
S. X superba (perennial salvia)
Blue salvia produces a blue flower spike 1½ to 3 feet tall; flowering begins in early summer and continues until fall. Perennial salvia produces violet-blue flower spikes. Both are useful in backgrounds and when a spike effect is desired. S. elegans (pineapple sage) is a late-blooming red species reaching 4 to 5 feet high. S. leucantha (Mexican sage), a tall, bushy, late-blooming purple species is cold tender in North Georgia. Many other salvia species are also cultivated, including the annual S. splendens (scarlet sage).
S. virens (green lavender cotton)
Both are grown primarily for their foliage, silver-gray and bright green respectively. Plants form a broad spreading mound 1½ feet tall and wide. They are frequently used for edging. Both require full sun and well-drained soils.
There are dozens of sedum species cultivated that vary tremendously in growth habit. This species is among the showiest. Colors range from white to red. Blooming in late summer until frost, plants are effective as single specimens or in small groups. Heights range from 1½ to 2 feet. Full sun or light shade is satisfactory, but well-drained soils are essential.
Shasta daisyShasta daisy grows easily and performs well in most parts of the state. Flowering in midsummer, it is used extensively in borders and for cut flowers. Heights range from 1 to 3 feet depending on variety; single-, semi-double- and double-flowered varieties are available. Shasta daisies do best in full sun but tolerate light shade.
St. John's wort is a tough perennial generally used as a ground cover. It can adapt to a wide variety of conditions and will tolerate hot, dry conditions. Bright yellow flowers are produced in summer. The foliage is usually evergreen but occasionally winter burns. Plants can be renewed by cutting back severely in early spring before new growth begins.
Easy to grow, the plant produces a rosette of foliage 12 to 15 inches high that has light blue flowers 1 to 2 inches in diameter. It is tolerant of heat and drought and is used in borders as a cut flower.
Sweet William grows 1 to 2 feet tall, producing flowers in dense flattop clusters. It is useful in borders, edging and as a cut flower. It blooms in late spring and early summer, then typically declines during the heat of summer. Colors range from white to pink, red and lavender. Sweet William is a short-lived perennial often acting as a biennial in the Southeast.
Numerous species and varieties are cultivated. Grown as a culinary herb, thyme is also an attractive garden perennial well suited to rock gardens, interplanting among stones and, of course, herb gardens. Full sun and well-drained soils are essential.
Tritoma produces a strong textural feature in the garden and is usually used for accent. The flower spikes are held high above the grasslike foliage, which is semi-evergreen. Colors range from cream to yellow and the more familiar coral red. Bloom time ranges from early summer to fall depending on variety.
V. tenuisecta (moss verbena)
Both are low-growing, spreading, and floriferous. 'Rosea' is the best known V. canadensis variety. Moss verbena varies from blue to purple, lilac and violet; a white variety, 'Alba' is also available. Moss verbena is often seen growing along the roadsides of Georgia. V. X hybrida varieties, usually treated as annuals, may perform as perennials in mild climates.
A number of varieties are available, with most ranging in height from about 1 to 2 feet. Most are blue, but white varieties are also available. Peak bloom time is midsummer. The spiky blue flowers can be used to good effect in perennial borders. V. repens is a very low-growing mat-forming type with evergreen foliage.
V. major
Vinca is an evergreen perennial often used as a ground cover in shade or partial-shade. Both species produce attractive blue flowers; white varieties are also available. V. minor is smaller and more compact; both spread to form a dense mat. Do not confuse the true vincas with Catharanthus roseus, also called periwinkle, which is a widely grown annual.
V. odorata (sweet violet)
V. tricolor (Johnny-jump-up)
Horned violets are low-growing and used for bedding and edging. Sweet violets produce the familiar sweet-smelling violets; the foliage is also quite attractive in mass. Johnny-jump-ups are short-lived perennials much like the familiar pansy, which is not perennial in Georgia.
Additional Perennials
Many other lesser-known perennials grow well in Georgia. In a few cases they may be slightly more demanding, but for the perennial enthusiast are certainly worth trying. Some possibilities include:
| Common Name | Botanical Name |
| Bears Breeches | Acanthus mollis |
| Blackberry Lily | Belamcanda chinensis |
| Blue Fescue | Festuca ovina glauca |
| Blue Stars | Amsonia species |
| Boltonia | Boltonia asteroides |
| Catnip | Nepeta cataria |
| Carolina Lupine | Thermopsis caroliniana |
| Chinese Bellflower | Platycodon grandiflorus |
| Chinese Lantern | Physalis alkekengi |
| Epimedium | Epimedium species and hybrids |
| Evening Primrose (Sundrops) | Oenothera species |
| False Sunflower | Heliopsis helianthoides |
| Filipendula | Filipendula species |
| Flax | Linum perenne |
| Fleebane | Erigeron species |
| Gas Plant | Dictamnus albus |
| Geranium | Geranium sanquineum |
| Gerbera Daisy | Gerbera jamesonii |
| Germander | Teucrium chamaedrys |
| Globe Thistle | Echinops retro |
| Goatsbeard | Aruncus dioicus |
| Heartleaf Begonia | Begenia cordifolia |
| Hen-and-Chicks | Sempervivum tectorum |
| Lady's Mantle | Alchemillia mollis |
| Lavender | Lavendula officinalis |
| Lamb's Ear | Stachys byzantina |
| Leopard's Bane | Doronicum cordatum |
| Meadow Rue | Thalictrum aquilegifolium |
| Monkshood | Aconitum species |
| Pasqueflower | Anemone pulsatilla |
| Pincushion Plant | Scabiosa caucasica |
| Plumbago | Ceratostigma plumbaginoides |
| Sea Pink | Armeria maritima |
| Sea Statice | Limonium latifolium |
| Self-Heal (Heal-All) | Prunella vulgaris |
| Siberian Bugloss | Brunnera macrophylla |
| Snakeroot | Cimicifuga racemosa |
| Sneezeweed | Helenium autumnale |
| Spiderwort | Tradescantia virginiana |
Quick Reference to Common Perennials
| Name | Height | Color1 | Bloom2 | Exposure | Comments | ||
| Shade | Partial Shade | Sun | |||||
| Achillea | 2-4' | W,P,Y,G | Su | * | |||
| Ajuga | 2-3" | B,W,P | Sp | * | * | * | |
| Alyssum | 9-12" | Y | SP | * | |||
| Artemisia | 1-3' | * | * | see text | |||
| Asclepias | 1-2' | O | Su | * | |||
| Aster | 1-5' | all | Su+/F | * | |||
| Astilbe | 1-3' | W,P,R | SP | * | * | ||
| Baptisia | 3' | B | SP | * | * | ||
| Begonia | 12" | P,W | -Su/F | * | * | ||
| Buddleia | 3-6' | W,B,P,O | Su/F | * | * | ||
| Candytuft | 12" | W | SP | * | * | ||
| Carnation | 12" | -B | SP/Su | * | |||
| Caryopteris | 3-4' | B | Su+ | * | |||
| Centaurea | 12" | B | -Su | * | * | ||
| Ceratostigma | 2-3' | B | Su+ | * | |||
| Chrysanthemum | 1-3' | -B | Su/F | * | see text | ||
| Chrysogonum | 3" | Y | SP/-Su | * | * | ||
| Columbine | 2-3' | W,P,B,Y | SP | * | |||
| Coreopsis | 1-3' | Y,G | Su | * | |||
| Delphinium | 1-5' | B,W,L | SP/Su | * | see text | ||
| Dianthus | 12" | P,W,R,Y | SP/Su | * | |||
| Dicentra | 1-3' | W,P | SP+/Su | * | * | ||
| Foxglove | 2-6' | W,P,Y,L | SP+ | * | * | ||
| Gaillardia | 1-2½' | Y,R,O | Su/F | * | |||
| Gaura | 2-3' | W | Su- | * | |||
| Goldenrod | 1-3' | G | Su+/F | * | |||
| Gypsophila | 2-4' | W | -Su/F | * | |||
| Hardy Ageratum | 1-2' | B,W | F | * | * | ||
| Helleborus | 12-15" | W,P,L | W/SP | * | * | ||
| Hemerocallis | 1-4' | -B | Su | * | * | ||
| Heuchera | 6-12" | W,P,R | SP/-Su | * | * | * | |
| Hibiscus | 3-8' | W,P,R | Su | * | |||
| Hollyhock | 4-8' | -B | SP+/-Su | * | |||
| Hosta | 1-3' | * | * | see text | |||
| Iris | 2-4' | all | SP/-Su | * | * | see text | |
| Japanese Anemone | 3' | W,P | Su+/F | * | * | ||
| Lantana | 4-6' | O,Y | SP/Su/F | * | * | ||
| Liatris | 2-6' | L,P | Su/F | * | * | ||
| Liriope | 1-2' | * | * | * | see text | ||
| Lobelia | 2-3' | R,B | Su+ | * | |||
| Monarda | 2-3' | W,R,P | SP+/Su | * | |||
| Ophiopogon | ½-2' | * | * | * | see text | ||
| Pachysandra | 6-8" | * | * | ||||
| Pampas Grass | 5-10' | W,P | Su+/F | * | * | ||
| Peony | 3-4' | W,P,R | SP/SP+ | * | * | ||
| Phlox | 1"-3' | all | SP/Su | * | * | * | see text |
| Physostegia | 1½-7' | W,P,R | Su | * | * | ||
| Poppy (Oriental) | 2-3' | W,P,O,R | SP+ | * | * | ||
| Purple Coneflower | 3-5' | L/P | Su | * | * | ||
| Rudbeckia | 2-3' | Y,O,G | Su/F | * | |||
| Salvia | ½-5' | W,B,R,L | Su/F | * | * | see text | |
| Santolina | 1½' | * | see text | ||||
| Sedum | 1"-2' | W,P,R | SP/F | * | see text | ||
| Shasta Daisy | 1-3' | W | -Su/Su | * | * | ||
| St. John's Wort | 6-12" | Y | Su | * | * | ||
| Stokesia | 12-15" | B | Su | * | |||
| Swamp Sunflower | 5-8' | Y | F | * | |||
| Sweet William | 1-2' | W,P,R,L | SP+/-Su | * | |||
| Tritoma | 2-4' | R,Y,O | Su | * | * | ||
| Thymus | 3-6" | B,L | Su | * | |||
| Verbena | 6" | W,B,L | SP/F | * | |||
| Veronica | 1"-2' | B,W | Su | * | * | ||
| Vinca | 3-6" | B,W | SP | * | * | ||
| Viola | 3-6" | all | SP/Su | * | * | * | see text |
| 1 Color: G = gold, W = white, P = pink, Y = yellow, R = red, B = blue, O = orange, L = lavender, all = all colors, - = indicates absence of a single color, all others represented. 2 Bloom: SP = spring, Su = summer, F = fall, W = winter, - = early, + = late, / = range of bloom. |
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Status and Revision History
Published on Sep 01, 1999
Published on Feb 24, 2009
Published with Full Review on Jun 26, 2012
Published with Full Review on Feb 01, 2016
Published with Full Review on May 27, 2020
Published with Full Review on Nov 14, 2023