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Hollyhock Mallow to Lupine

Common Name Height (in) Space (ft) Flower Colors Flowering
Hollyhock Mallow 24-36 1.5 Pink, White July- August

Hollyhock MallowMalva alcea has light green leaves similar in appearance to hollyhock; loose clusters of flowers with five petals. Requires well drained soil; tolerant of drought; best in somewhat lean soil. Full sun to partial shade. Short lived but self seeds. `Fastigiata' is taller with a narrower more upright growth habit.
 

Common Name Height (in) Space (ft) Flower Colors Flowering
Hosta 6-36 1-2 Blue, Lavender, White June- August

HostasPlantain Lily is primarily grown for foliage color and patterns; range in color from gold to green to blue green to variegated and in size from miniatures to large bold plants. Tubular flowers start opening at bottom of stalk; some may rebloom. Bloom for 2-3 weeks; 4-5 flower stalks per plant. Flowers may be fragrant. Slow growers; best used in groups of three or more. Prefer soil high in organic matter with a good moisture supply. Needs good drainage especially in the spring. Prefers partial to full shade. Bleached or dry leaves indicate sunburn. Slugs can be a problem. Slow to emerge in the spring. `Royal Standard' - excellent cultivar. Hosta plantaginea (August Lily) is grown for its fragrant white flowers in late summer. Hosta ventricosa is one of the most floriferous.

Common Name Height (in) Space (in) Flower Colors Flowering
Hyacinth 8-12 6-8 Various April- May

HyacinthVery odorous flowers. Don't cut back until completely yellow; mid summer. Bulbs may rot if too wet. Prefers full sun to partial shade and well drained soil; heavy feeders. Tend to be short lived. Plant in September; needs 6 weeks to root. Winter mulch is helpful. Set all bulbs at the same depth; will all flower at same time. Plant in groups or mass.
 

Common Name Height (in) Space (ft) Flower Colors Flowering
Iris Various
Bearded
Dwarf 4-12 .5-1 April-May
Tall & Intermediate 18-36 1-1.5 May-June
Siberian 18-36 1.5 June
Spuria 30-48 1.5 June- July

IrisBearded Iris have broad grass-like leaves with large, complex, orchid-like flowers; flower buds open sequentially up the stem. Purples are the most vigorous. Prefers full sun and moderately fertile soil. Needs a least a half day of full sun; hot sun fades flower color. Good cut flowers. Requires good drainage; susceptible to Crown Rot and Iris Borer especially if too wet or rhizomes are damaged. Likes summer watering and low nitrogen fertilizer. Winter mulch may be helpful. Plant rhizomes together in a group with the leaf fans facing outward. Cover the rhizomes with just a trace of soil.

Beardless (Siberian & Spuria) Iris have narrower leaves and flower parts than Bearded Iris. Good cut flowers. Prefer full sun and moist well drained soil; high in organic matter. Winter mulch may be beneficial. Rhizomes are small, tough, and fibrous; root deeply. When planting, cover rhizomes with 2" of soil; don't bloom the 1st year. Siberian Iris have small flowers and fine foliage; flower just as the Bearded Iris are finishing. Spuria (Butterfly) Iris are taller than Siberian and have broader leaves; flowers are larger and later.

Common Name Height (in) Space (ft) Flower Colors Flowering
Jacob's Ladder 18-24 1.5 Blue, Pink, White May-June

Jacob's LadderPolemonium cearuleum has pinnately divided leaves whose leaflets are spaced as regularly as rungs on a ladder; small cup-shaped flowers are borne in branching clusters. Yellow orange stamens. Prefers partial shade but does well in full sun if not stressed for moisture.

 

Common Name Height (in) Space (ft) Flower Colors Flowering
Joe-Pye Weed 30-60 1.5-2 Pink, Purple August

Joe Pye WeedEupatorium purpureum has long leaves in whorls of 4 around the purplish stems; vanilla scented when bruised. 12-18 inch clusters of sweet scented flowers; attract butterflies. Prefers full sun to partial shade. Thrives in dry poor soil; rapid spreading in fertile moist soil.

 

Common Name Height (in) Space (ft) Flower Colors Flowering
Lady's Mantle 6-15 1 Green, Yellow May-June

Lady's MantleAlchemilla mollis has large round or globe-shaped, grayish green leaves; fine hairs covering the foliage giving it a velvety feel. Small, yellow-green flowers lack petals but are numerous; borne on many branched cymes. Blooms for 6 weeks. Needs a fairly rich soil and a constant moisture supply; not especially drought tolerant. Tolerates full sun with good moisture.
 

Lamiam (see Ground Covers)

Lamiastrum (see Ground Covers)

Common Name Height (in) Space (ft) Flower Colors Flowering
Liatris spicata 18-30 1-1.5 Lavender, Pink, White July-August

LiatrisGayfeather has grassy, linear leaves in a thick tufty mass from which the flower stalks arise. The compact flower clusters resemble a bottle brush. Blooms from the tip downward; trim flower stalks after bloom; attract butterflies. Good as a cut flower or for drying; may require staking. Best in full sun with lean to moderately fertile soil. Needs good drainage, especially in the spring; fairly drought tolerant. Best in groups of 3 or more; plant 4-6" deep.

Common Name Height (in) Space (ft) Flower Colors Flowering
Lily 1
Asiatic Hybrids 24-36 Various June-July
Aurelian Hybrids 30-48 Various July-August
Orientals 24-48 Various August-Sept
Candlestick 24-36 Orange June

Candlestick LilyLilies are valued for their colorful display of flowers; many flower shaped but outfacing and upfacing types are most useful. Cut as few leaves as possible when taking flowers; remove spent flowers before seed set. Taller varieties may need to be staked; summer mulch is beneficial. Prefer a loamy soil with good drainage; wet soil can cause bulb rot. 2/3 day of full sun needed. Plant in groups of 3-5 bulbs of a variety for a better show. Plant hardy varieties in September; less hardy bulbs in May. Set large bulbs 4-6" deep; smaller 2-4" deep. Never allow bulbs to dry out. Mulch 1st winter after planting or transplanting.

Asiatic Hybrids including the Mid-Century and Patterson Hybrids are the hardiest and easiest to grow. Upright facing, outfacing and Turk's cap flowers; most are not fragrant. Good cultivars include: `Connecticut King' (upright yellow with orange cast); `Enchantment' (upright red-orange); `Firecracker' (upright red); `Polar Bear' (upright near white); `Corsage' (outfacing pink) and `Citronella' (turk's cap yellow-gold). Aurelian Hybrids (trumpets) resemble the Asiatics but bloom later and have larger but fewer flowers; often fragrant. Whiskers inside the flower face. Include Olympic Hybrids, Magic strain and Golden Clarion strain. Variable in hardiness but not fully hardy; mulch for winter. Oriental Lilies includes Lilium auratum, rubrum, speciosum, and their hybrids: Potomac and Imperial strains. Large spectacular blooms; trumpet, bowl, flat and recurved forms. Bloom late; not enough time to rebuild bulb. Mulch heavy for winter or plant in spring. Digging bulbs in fall and replanting in spring may help. Borderline in hardiness; short lived. Candlestick (Red Russian) Lillium hollandicum red-orange cup-shaped flower; outward facing. Very common here; hardy.

Lily of the Valley (see Ground Covers)

Common Name Height (in) Space (ft) Flower Colors Flowering
Lungwort 9-18 .5-1 Pink to Blue April-May

Roy Davidson LungwortPulmonaria saccharata (Bethlehem Sage) has mostly basal, lance-shaped, dark green leaves spotted with white; persists late into fall. Once thought to cure lung ailments. Drooping clusters of funnel-shaped flowers open pink but gradually turns blue; open before or with leaves. Prefers partial to full shade and cool moist well drained organic soil. Water during dry spells; foliage may scorch in full sun. Long lived and non-invasive.

Common Name Height (in) Space (ft) Flower Colors Flowering
Lupine 18-36 1.5 Various June-July

Russell Hybrid LupineLupinus `Russell Hybrids' have grayish or soft green palmately lobed leaves and pea-shaped flowers on long spikes. Flowers from bottom up; cut back for a second bloom. Seeds and seed pods are poisonous. Stake in windy areas. Best in groups or mass plantings. Prefers high humidity and well drained soil especially in the winter. Water when dry; use a mulch to keep roots cool. Don't do well in areas with hot dry summers; short lived here. Nitrogen fixers; takes time to get started. Slugs, aphids and mildew can be a problem. Don't move well.


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

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