Flowering Perennials: Characteristics and Culture

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Reviewed by David H. Trinklein
Division of Plant Sciences
Mary Kroening
Missouri Master Gardener Program

Flowering perennials represent a large group of garden plants with roots that persist from year to year. Stems and leaves of some may remain, but in most, the tops die back to the soil each winter.

Perennials are suitable for many locations. Most frequently, they are incorporated in a flower border that they share with annual flowers and shrubs. Perennials with similar cultural requirements are grouped into plantings known as rock gardens, wildflower gardens, bog gardens or perennial flower borders.

The pages of this guide list some major perennial plants and their important characteristics and cultural preferences.

Space is not available here to fully describe the plants and flowers. Reviewing garden catalogs or visiting a nursery, garden center or botanic garden will help you become familiar with available plants.

Mixed borders of perennials Figure 1
Mixed borders of both perennials and herbaceous perennials can provide an interesting landscape year-round.
 

Description of terms and codes

Height

The height range, given in inches, helps to determine whether a plant is suitable for an edging (1–12 inches), for the middle of a bed (12–36 inches), or for a background plant (more than 36 inches). Where a very wide range is given (such as Bellflower, 8–36 inches), some dwarf varieties are indicated.

Bloom period

The month or months of peak bloom are listed. Time of flowering varies with exposure and climatic area. These listings are primarily for central Missouri.

Color(s)

Plant are keyed with their most common colors. Many blends, shades and tints exist.

  • Blue (B)
  • Green (G)
  • Lavender (L)
  • Orange (O)
  • Pink (P)
  • Red (R)
  • Violet (V)
  • White (W)
  • Yellow (Y)

Cultural requirements

Light

  • Full sun (FS)
    Locate plant away from the shade of buildings, large trees or other objects that will not allow at least six hours of direct sunlight each day.
  • Semi-shade (SS)
    Give partial shade either as a long period of light shade or as more dense shade during the afternoon. Most plants in this category must have shade during the hottest part of the day.
  • Shade (S)
    These plants must have continuous shade with no direct sun. In heavy shade, other necessary cultural requirements must be carefully fulfilled.

Moisture

  • Well drained (WD)
    Periods of standing water on the soil are damaging to perennials in both summer and winter. In heavy soils, add liberal amounts of organic matter to ensure good internal soil drainage. If external drainage is poor, consider raised beds or drain tile below. For information on improving soils, see MU Extension publication G6955, Improving Lawn and Landscape Soils.
  • Dry (D)
    These plants will not tolerate moist conditions very long, but they will withstand considerable dryness.
  • Moist, but well drained (M)
    Plants in this category do not tolerate drying, but they also do not tolerate any water standing around their roots. In the garden, they need regular watering during dry periods.
  • Wet (W)
    Plants will tolerate boggy conditions or even standing water. However, they are not the aquatics, such as waterlilies. Aquatic plants are not included in this publication.

Soil

  • Loam (L)
    Any good well-kept garden soil fits this category. Yearly additions of organic matter help develop a good loam. Where a poor soil is to be planted for the first time, amend it by mixing in at least 4 inches of organic matter.
  • Sandy loam (SL)
    This type of soil is required mainly by plants that need excellent drainage. If the original soil is a tight clay, large amounts (at least 50 percent) of sand will have to be added to achieve this type of soil.
  • Organic soil (OS)
    Some plants require a soil very high in organic materials that have an acid reaction. Where soils are not naturally this way, liberal amounts (up to 33 percent) of peat moss mixed thoroughly with the soil can achieve this condition, and annual applications of sulphur may be necessary for maintenance.
  • Woodland soil (WS)
    Such a soil is usually required for the wildflower garden. It results from decomposition of leaves and is fairly high in organic matter. It is not necessarily very acid soil. Add liberal quantities of leaf compost or peat to prepare this type of soil.

Relative ease of care

  • Easy (E)
  • Moderate (M)
  • Challenging (C)

Remarks

Unusual or outstanding plant and cultural characteristics are listed briefly. Included are notes on cultural ease, winter hardiness, or special uses, or emphasis of an extremely important cultural requirement.

Table 1. Characteristics and culture of flowering perennials.

Common name,
Scientific name
Height
(inches)
Bloom
period
ColorLightMoistureSoilRelative
ease
Remarks
Anemone, Japanese,
Anemone japonica
18–30Sept.–frostW, PSSWDLMDislikes transplanting. Spring plant only.
Anthemis, Golden Marguerite,
Anthemis tinctoria
12–24Aug.–frostYFSWDLMAttractive fine-cut leaves. Divide every 3 to 4 years. Self-seeds readily.
Artemisia,
Artemisia sp.
9–36Aug.–Sept.W, YFSWDL, SEMany species and varieties. Includes Silver King and Silver Mound.
Aster, Michaelmas daisy,
Aster hybrids
12–72July–frostW, R, B, L, V, PFSM, WDLMMany varieties of differing growth habit. Divide every other year.
Astilbe,
Astilbe sp.
12–24May–JuneW, PFSM, WDLEEasy to grow. Sometimes incorrectly called spirea.
Baby’s breath,
Gypsophila paniculata
18–30June–JulyW, PFSWDLEEasy to grow. Avoid acid soil. Add lime if necessary.
Balloon flower,
Platycodon grandiflorum
18–24May–Aug.B, W, PFSWDSMWeak-stemmed plant, may need staking. Avoid wet places.
Basket-of-gold,
Aurinia saxatile
12–18MayYFSWDSMFoliage gray. Suitable for rock garden.
Beardtongue,
Penstemon sp.
6–28June–JulyP, R, LFSWDSMAvoid acid soil. Fairly short-lived. Some good as cut flower.
Bee-balm,
Monarda didyma
18–24July–Aug.R, P, L, WFSWD, DLMOther species available. Useful for hot, dry places. Also endures light shade.
Bellflower,
Campanula sp.
8–36May–JulyW, BFS, SSWDSMNeeds excellent drainage. Avoid clay. Mulch in winter. Species vary in height.
Bergenia,
Bergenia cordifolia
12–15May–JuneP, WSSMLMWaxy foliage remains green in winter.
Blackberry lily,
Belamcanda chinensis
24–36July–Aug.OFSWDLEFlowers followed by blackberry-like seed clusters.
Black-eyed Susan,
Rudbeckia fulgida
24–36June–JulyY, OFSWDLEVery tolerant. Good for bold splash of color.
Bleeding heart, Old-fashioned,
Dicentra spectabilis
18–24MayP, RFS, SSWDLMEasy to grow. Should be fall planted.
Blue false indigo,
Baptisia australis
36–48May–JuneBFSWDS, LEAlso called rattlebush. Missouri native.
Blue flax,
Linum perenne
12–28June–Aug.BFSWDLELikes poor soil. Lasts about 3 years. Easily grown from seeds planted in spring.
Boltonia,
Boltonia asteroides
24–48Aug.–Sept.W, PFSWDLEChoose named cultivars. Species gets too tall for most gardens.
Brunnera, Siberian bugloss,
Brunnera macrophylla
12–18May–JuneBSSM, WDLMResembles forget-me-not.
Butterfly weed,
Asclepias tuberosa
12–20Aug.O, Y, RFSWDSEDifficult to transplant. Suited to hot, dry sites.
Candytuft, Evergreen,
Iberis sempervirens
8–12AprilWFSWDLMFor rock garden and stone walls, or groundcover.
Chrysanthemum,
Dendranthema hybrids
10–36July–frostW, R, O, V, L, PFSWDLEVarieties determine growth. Pinch tips of tall types in early summer for bushiness.
Columbine,
Aquilegia hybrids
6–36April–JuneW, R, P, V, B, L, YFS, SSWDS, LEFairly short-lived. Reseeds easily. Sow seeds in early summer.
Coneflower, Purple,
Echinacea purpurea
24–36Aug.–Oct.PFSWDLETolerates very poor soil. Flower “petals” drooping.
Coral bells,
Heuchera sanguinea
18–24JuneW, P, RFS, SSWDLMDivide every 3 years. Good cut flower.
Coreopsis, Thread-leaf tickseed,
Coreopsis verticillata
18–30June–Aug.YFS, SSWD, MLEEasy to grow. Blends well with other perennials. Blooms all summer.
Daylily,
Hemerocallis hybrids
15–36June–Sept.R, O, Y, L, PFS, SSWD, M, DLEEasily grown. Adapts to many conditions. Excellent hybrids available.
Delphinium,
Delphinium hybrids
36–60July–Aug.W, B, LSSWDLMLikes cool weather. Give afternoon shade. Needs excellent drainage.
Evening primrose,
Oenothera sp.
8–36July–Aug.Y, PFSWDS, LMFlowers open in evenings. Good rock garden plant. Some are invasive.
False dragonhead,
Physostegia virginiana
18–48July–Sept.P, WFS, SSM, WDLEAlso called obedient plant. A vigorous grower.
False sunflower,
Heliopsis helianthoides
36July–Sept.Y, OFSWDLMFlowers good for cutting.
Foamflower,
Tiarella cordifolia
10–12May–JuneW, PSS, SWDLMCompact, spreading growth habit. Flowers similar to Astilbe.
Foxglove,
Digitalis purpurea
24–28JuneV, P, WSSM, WDLMGrow as biennial. Sow seed in coldframe in Aug. or Sept. A cool-climate plant.
Gaillardia,
Gaillardia x grandiflora
24–30July–Sept.Y, RFSWDLMEasy to grow. Good cut flower.
Geum, Avens,
Geum hybrids
12–20JulyR, O, YFSWDSMDivide every 3 years. Provide winter mulch.
Globe thistle,
Echinops ritro
24–48July–Sept.BFS, SSWDS, LETolerates poor soil. Replant every 3 to 4 years.
Globeflower,
Trollius europaeus
12–18MayY, OFS, SSM, WDLMDo not let dry out. Good beside pools.
Gooseneck loosestrife,
Lysimachia clethroides
24–36July–Aug.WFSWDLEVery aggressive. May become invasive.
Helenium, Sneezeweed,
Helenium autumnale
36–48Aug.–Oct.Y, RFSM, WDLEGood cut flower. Divide and replant every 3 years.
Hibiscus,
Hibiscus palustris
24–60July–Sept.W,P, RFSM, WDLMAlso called H. moscheutos. Flowers very large.
Hollyhock,
Alcea rosea
48–72July–Aug.W,P, RFSWDLEBest grown as biennial. Seed outdoors in July.
Hosta, Plantain lily,
Hosta sp.
6–36July–Aug.W, LSS, SM, WDLEUseful as groundcover. Leaves large in some types.
Iris, German,
Iris germanica
12–36April–JuneB, V, R, P, W, Y, L, OFSWDLEEasy to grow. Many varieties available.
Iris, Japanese,
Iris kaempferi
18–36June–JulyB, W, Y, L, PFS, SSM, WDLMSuitable at the edge of ponds. Replant every 4 to 5 years.
Iris, Siberian,
Iris siberica
18–24May–JuneW, BFS, SSM, WDLELikes rich soil. Never let dry out.
Lamb’s ears,
Stachys byzantina
12–18JunePFS, SSWDS, LMWill grow in dry, poor soils. Woolly grayish leaves.
Lady’s mantle,
Alchemilla mollis
10–12June–JulyYFS, SSMLMCompact, spreading habit. Prefers a cool, moist location.
Lavender,
Lavendula angustifolia
12–20July–Aug.LFSWDSMLikes poor soil. Very fragrant foliage.
Leadwort,
Ceratostigma plumbaginoides
8–12Aug.–frostBFSWDSESometimes called plumbago. Semiwoody groundcover.
Lenten rose,
Helleborus niger
5–8Feb.–MarchWSSM, WDLCNeeds rich soil. Do not transplant or cultivate.
Leopard’s bane,
Doronicum caucasicum
12–18AprilYFS, SSM, WDLEDormant in July–Aug. Plant among spring bulbs.
Liatris, Gayfeather,
Liatris sp.
24–48July–Sept.W, LFSWDSEAdapts well to dry locations. Spike flowers open from top downward.
Lily turf,
Liriope muscari
6–10Aug.V, WFS, SS, SWDS, LEEvergreen border plant or groundcover. Cut back old growth in spring.
Lily-of-the-valley,
Convallaria majalis
6–8MayW, PSSM, WDLEUsed for groundcover and cutting of flowers.
Loosestrife, yellow,
Lysimachia punctata
18–30July–Sept.YFS, SSM, WLENeeds semishade in dry soils.
Lungwort,
Pulmonaria longifolia
8–12May–JuneBSS, SMLMVery distinctive foliage with unusual variegation.
Lupine,
Lupinus hybrids
24–40June–JulyB, W, P, YFS, SSWDSCDislike hot summers. Short-lived in Midwest.
Meadow rue,
Thalictrum aquilegifolium
24–30June–JulyP, V, WFS, SSM, WDLMFoliage like columbine. Male and female plants.
Meadow sweet,
Filipendula vulgaris
24–36June–JulyW, PFS, SSWDLEFleecy, graceful flowers. Prefers humusenriched soil.
Painted daisy, Pyrethrum,
Tanacetum coccineum
12–24June–JulyP, R, WFSWDLCWill not tolerate wet soils. Replant every 3 years.
Pasque flower,
Pulsatilla vulgaris
6–10AprilB, WFSWDSMFor rock garden. Needs good drainage. No acid soil.
Peony,
Paeonia hybrids
18–36May–JuneW, P, RFS, SSWDLETransplant in Sept. Plant 2 to 3 inches deep in rich soil.
Perennial salvia,
Salvia x superba
18–24June–JulyB, VFSWDLEEffective blue flower color.
Phlox, Creeping,
Phlox subulata
3–5April–MayP, L, WFSWDSMAlso called ground pink or thrift. Tolerates poor soil.
Phlox, Garden,
Phlox paniculata
18–48June–Sept.R, P, L, WFS, SSWDLMMany varieties available. Sometimes listed as P. decussata.
Pincushion flower,
Scabiosa caucasica
18–24June–JulyBFSWDLMUnique flower with conspicuous stamens.
Pink, Cottage,
Dianthus plumarius
10–15May–JulyR, W, PFSWDLMVery fragrant. Bluish gray foliage. Edging plant.
Pink, Maiden,
Dianthus deltoides
4–9MayR, P, WFSWDSMDwarf pink. Gradually spreads to form a green mat.
Poppy, Iceland,
Papaver nudicaule
8–12JuneR, O, P, WFS, SSWDSMOften grown as annual. Seeds started indoors will flower in first season.
Poppy, Oriental,
Papaver orientalis
24–40May–JulyO, R, P, WFSWDSENeeds good drainage. Place in protected spot, or mulch in winter.
Primula, Primrose,
Primula polyantha
8–12MayB, O, Y, RSSWDSMMust be kept moist. Cannot survive summer heat and drought.
Red-hot poker, Tritoma,
Kniphofia hybrids
36–48July–Sept.O, Y, P, WFSWDSENeeds excellent drainage. Mulch in winter.
Rock soapwort,
Saponaria ocymoides
5–10June–JulyP, WFSWDSMPruning back helps retain compact form. Needs good drainage.
Russian sage,
Perovskia atriplicifolia
36–48June–JulyBFSWDLEUniquely colored, aromatic foliage. Good companion for plants with yellow flowers.
Sea lavender,
Limonium latifolium
15–24Aug.–Sept.B, WFSWDSMSometimes called statice. Large decorative foliage.
Sedum, Stonecrop,
Sedum sp.
4–24June–frostP, R, Y, WFSWDSEMany species available with differing growth habit and flower color.
Shasta daisy,
Leucanthemum x superbum
12–36June–Aug.WFSWDLMNeeds replanting every 2 to 3 years. Dwarf and tall forms available.
Snow-in-summer,
Cerastium tomentosum
3–5May–JuneWFSWDSMSmall gray woolly leaves. Forms dense carpet. Needs excellent drainage.
Spiderwort,
Tradescantia virginiana
8–24May–Aug.B, V, WSS, SM, WDLEEasily grown. Roots easily from the nodes.
Stoke’s aster,
Stokesia laevis
12–30Aug.–Sept.B, W, PFSWDSMNeeds good drainage. Mulch in winter.
Sweet pea, Perennial,
Lathyrus latifolius
60–96June–Aug.P, R, WFS, SSM, WD, DLEVery easy to grow. May crowd out other plants.
Sweet William,
Dianthus barbatus
6–15May–JuneR, P, WFSWDSEBiennial that self-sows easily. An “old-fashioned” favorite.
Thrift,
Armeria maritima
8–12June–JulyP, V, WFSWDSENeeds good drainage. Mulch in winter. An everlasting.
Tickseed,
Coreopsis grandiflora
24–36June–JulyY, OFSWDLETolerant of dry soils. Good for low maintenance areas.
Veronica, Speedwell,
Veronica sp.
2–36May–Sept.B, WFSWDLEEasy to grow. Species differ in growth habit.
Violet,
Viola sp.
6–8April–MayV, L, W, YFS, SSWD, MLEForms a dense mat. Reseeds easily.
Yarrow, Sneezewort,
Achillea sp.
2–36June–Aug.Y, P, R, WFSWDLEEasy to grow, but should be replanted every 3 to 4 years.

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