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Maltese Cross to Phlox

Common Name Height (in) Space (ft) Flower Colors Flowering
Maltese Cross 18-36 1-1.5 Red June-August

Maltese CrossLychinus chalcedonica (catchfly) has hairy stems and leaves; similar to Sweet William. Small, Maltese Cross-shaped flowers in dense rounded terminal heads. Cut back flower heads for rebloom. Leaves may brown and drop during the summer heat. May require staking. Prefers sun to partial shade and cool soil with good drainage. Often short lived.
 

Common Name Height (in) Space (ft) Flower Colors Flowering
Marsh Marigold 12-24 1-2 Yellow May-June

Marsh MarigoldCaltha palustris has single or double buttercup-like flowers with 5 shinny petal-like sepals; blooms as plants are emerging in spring. Rounded to slightly heart-shaped leaves with wavy, toothed margins; plant has a spreading growth habit. Likes full sun to partial shade. Plant in moist, fertile areas; will grow in 1-4" of water. Tolerates dry soil when dormant (about a month after flowering).
 

Common Name Height (in) Space (ft) Flower Colors Flowering
Meadow Rue 12-36 1-1.5 Various May-June

Meadow RueThalictrum sp has fine textured foliage which resembles that of columbine; tends to be basal and blue-green in color. Domed clusters of small, fuzzy, petal-less flowers. Male and female flowers on separate plants; male plants are somewhat showier. Staking may be necessary. Prefers partial shade and fairly rich soil; can grow in full sun if soil kept moist. Shallow rooted; use mulch to help reduce moisture stress. Best when grown in groups.

Common Name Height (in) Space (ft) Flower Colors Flowering
Meadowsweet 36-60 2-3 Pink, White June-July

Flora Plena MeadowsweetFilipendula plants resemble spireas. Have frothy heads of tiny, five petaled flowers with protruding stamens; deep green, pinnately divided leaves. Good substitute for astilbe. Prefers fairly rich, moist soil. Eastern exposure best; south and west often too hot and dry; if leaves become tattered or crispy, cut back and fresh foliage will emerge.  Mites can be a problem in hot dry sites.
 

Common Name Height (in) Space (ft) Flower Colors Flowering
Missouri Primrose 6-12 1.5 Yellow June-August

Missouri PrimroseOenothera missouriensis has bright green, willow-like foliage; semi-trailing growth habit. Reddish growing tips turn upward. Large slightly fragrant cup-shaped flowers; bloom last from evening through next day. Large winged seed pods; tan color often streaked with crimson. Great for dried arrangements. Late to emerge in spring. Good in hot sunny spots with well drained soil high in organic matter; die quickly if soil is poorly drained. Don't over fertilize; water when plants wilt. Don't over winter well in heavy wet soil. Best when grown in groups. Prefer to be undisturbed. Self seeds.

Common Name Height (in) Space (ft) Flower Colors Flowering
Monarda 12-36 1-1.5 Various July-August

Marshall's Delight MonardaBergamot is a coarse plant with hairy, mint smelling leaves; dense terminal clusters of flowers surrounded by showy colored bracts; good cut flower. Irresistible to bees and hummingbirds; cut back after flowering for rebloom. Spreads out over time but dies out in center. Prefers sun and well drained organic soil but can't be allowed to dry out. Need good air circulation. Mites and powdery mildew (mid July) can be a serious problem. 'Marshall's Delight'  & `Gardenview Scarlet'  have some mildew resistance. `Petite Delight' is half as tall but more susceptible to mildew. Native plants are lavender in color.

Common Name Height (in) Space (ft) Flower Colors Flowering
Monkshood 30-42 1 Blue, Purple July-August
Azure Monkshood 24-36 1 Blue August-Sept

MonkshoodAconitum napellus has glossy dark green, delphinium-like leaves; stay nice throughout the growing season. Tall spike-like flowers shaped-like a helmet or hood; good cut flower. All parts of the plant are poisonous. Prefer rich well drained soil and summer mulching. Never allow to dry out or stunting will occur; taller cultivars may need staking. In full sun and dry conditions, leaves will blacken. Mildew can be a problem. Best planted in groups of 3 or more; don’t like being moved. A. carmichaelii (Azure or Carmichael’s Monkshood) has strong sturdy flower stalks; don’t need staking.

Common Name Height (in) Space (ft) Flower Colors Flowering
Mountain Bluet 18-24 1-2 Blue May-August

Mountain BluetCentaurea montana has globular, thistle-like flowers with pink or reddish centers; blooms on and off if deadheaded. If unsightly after bloom, cut back for regrowth. Good cut flower. Stake to prevent splitting from rain damage. Foliage is gray-green; silvery when young. Prefer full sun to partial shade and well drained soil; wet soil in early spring can cause a problem. Withstand heat, drought and neglect fairly well. Spread rapidly in rich soil. Best in alkaline soil. Self seeds.

Common Name Height (in) Space (ft) Flower Colors Flowering
Obedient Plant 12-36 1-1.5 Lavender,Pink,White August-Sept

Variegated Obedient PlantPhysostegia virginiana (False Dragonhead) has willow-like dark green foliage and a great number of small trumpet-shaped flowers resembling snapdragons on terminal spikes; stems are square and tend to be strongly upright. Pastel colors; good contrast with bright colored flowers. Flowers are hinged, can be moved around the stem and will stay where placed; good cut flower. Tall varieties may need staking. Prefers sun to partial shade; can be invasive especially in fertile soil. Water when dry; doesn't like drought. Best grown in groups. Variegated form looks good all season.

Common Name Height (in) Space (ft) Flower Colors Flowering
Oriental Poppy 18-36 1-1.5 Various May-June

Oriental PoppyPapaver orientale has large, satiny, crepe paper-like blooms with black stamen; single or double. Buds nod but straighten up as they open; short bloom period. Good cut flower; seed pod is decorative. After bloom, flower stems and lower leaves dry down; exposed roots like a good baking. Plant has a thistle-like foliage; exudes a milky sap. May need to be staked. Open sprawling growth habit. Prefers full sun and well drained soil high in organic matter. Likes moisture in spring and when flowering; keep on dry side for rest of year. Root rot can be a serious problem; must have good drainage. When planting, set the root straight down.

Ostrich Fern (see Ground Cover)

Common Name Height (in) Space (ft) Flower Colors Flowering
Painted Daisy 12-24 1-1.5 Various May-June

Painted DaisyTanacetum coccineum, (Pyrethrum Daisy or Colored Marguerite), has fern-like foliage and 1" daisy-like flowers with yellow centers borne on erect stems; single or double flowers. Pinch side buds to enhance flower size; cut stems to ground after flowering to encourage rebloom; may need staking. Prefer sun to partial shade. Feed during growing season;  too wet in the spring can be fatal. Source of the insecticide Pyrethrum. Use in groups of at least three or in mass; tend to be short lived.

Common Name Height (in) Space (ft) Flower Colors Flowering
Pasque Flower 9-12 1 Pink,Red,White April-May

Pasque FlowerAnemone pulsatilla (Pulsatilla vulgaris) has gray green carrot-like foliage in a basal clump. Leaves unwrap as bell- shaped flowers open; seeds in masses of silvery down (pods). Poor flowering in the shade. Does best in full sun to partial shade and moderately rich soil. Prefers cool conditions; mulch in summer to keep soil cool. Water during dry periods. Loose mulch for winter; must be well drained especially in early spring. Native Pasque flower does poorly in the flower garden.

Common Name Height (in) Space (ft) Flower Colors Flowering
Penstemon 18-24 1-1.5 Various June-August

PenstemonBeard Tongue foliage is green with wiry thin stems giving an airy appearance; the nodding, two-lipped flowers are slender and tubular. Cut back after flowering. Tolerates dry periods once established. Don't use mulch during wet periods; crowns may rot. Best in sun to part shade and lean soil; rich soil will cause them to "grow themselves to death". Light mulch for winter; may be short lived. Good planted in mass. Good cultivars include: `Prairie Dusk', `Prairie Fire' and `Elfin Pink'. `Husker Red' has colorful red foliage; pale pink flowers.

Common Name Height (in) Space (ft) Flower Colors Flowering
Peony
Common 24-36 3 Various May-June
Fern Leaf 18-24 2 Pink,Red May

Red Red Rose PeonyPaeonia has glossy green leaves which remain attractive for the entire season; single, semi-double and double flower types. Doubles are the most popular, bloom the latest and flowers last the longest but flowers flop badly in the wind and rain; wire hoops, rings etc. can be used. Singles stand up much better. Remove side buds to get larger flowers. Ants aren't needed for flowering; buds secrete a super sweet solution that the ants like to eat. Prefer full sun and well drained soil; drought tolerant but like water during dry periods. Heavy feeders which prefer deeply prepared soil with organic matter added. Botrytis blight is a serious problem; to control cut stems to just below ground level in late fall. Good air circulation is helpful. Top eye can be no more than 2" deep when planted; will have good bloom 2nd year after planting. Fern Leaf Peony blooms earlier, is less vigorous and likes afternoon shade; foliage yellows and dies back in midsummer. Slow to increase in size. Tree Peonies are very borderline in hardiness.

Common Name Height (in) Space (ft) Flower Colors Flowering
Perennial Aster 6-48 1-2 Various August-Sept
Alpine Aster 6-10 1 Blue,Purple June-July

Alma Potsche AsterAster novae-angliae (New England Aster) and Aster novi-belgii (New York Aster or Michaelmas Daisy) form neat tidy clumps; have lance-shaped leaves and yellow centered daisy flowers. New England Aster is more reliable here. Encourage branching by pinching back in spring and early summer but remember pinching retards flowering. Good cut flower; select early flowering cultivars. Full sun; lighter bloom in part shade. Staking may be necessary. Dislike drought and intense heat. In dry sites may lose lower leaves by midsummer. Tolerates moisture but wet soil in early spring can be a problem. Susceptible to powdery mildew. `Alma Potschke' is a good cultivar. Alpine Aster has gray-green foliage which turns green in summer; likes cool conditions.

Common Name Height (in) Space (ft) Flower Colors Flowering
Phlox
Early Garden 18-24 1.5 Pink,Purple,White June-August
Perennial Summer 24-36 1.5-2 Various July-August

Perennial Summer PhloxPhlox carolina (suffruticosa) (Early Garden) has glossier, thicker, shinny dark green leaves and blooms a month earlier than Garden Phlox; less affected by mites and mildew. Fragrant flowers; cut back for rebloom. Full sun and moderately rich soil. Short lived in wet soils; sterile and doesn't self seed. `Miss Lingard' is a good white variety with better disease resistance. Phlox paniculata (Tall Garden Phlox) has mildly fragrant flowers borne on large panicles or clusters; hot sun fades flowers. When new shoots are 4-6" tall, thin each clump to 4-5 shoots; 4-6" apart. Crowded plants reduce flower size and increase the amount of leaf diseases. Blooms for at least a month; remove spent blooms to later rebloom and prevent self seeding. Prefers full sun and moderately fertile soil; keep evenly moist. Doesn't like hot summers and drought stress; short lived if wet in spring. Never get the foliage wet; Powdery Mildew, leaf spot and mites can be a serious problem. Lower leaves tend to get unsightly from mildew; whites tend to be more resistant. `D.H. Forbes', `Starfire' & `David' have some resistance. Dwarf Creeping or Moss Phlox (see Ground Cover)


Todd Weinmann, Extension Horticulturist & Master Gardener Coordinator
Phone: (701) 241-5707
E-mail: todd.weinmann@ndsu.edu

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