Common Yarrow
Achillea millefolium
Asteraceae
Form: Rhizomatous, spreading clumps of foliage,
with species and many cultivars forming large colonies; low and matlike;
foliage height to 12 inches, spread to 48 inches or more
Foliage: Alternate, bright green to slightly gray or
dusty green; very finely divided or dissected with a distinct musky odor;
leaves to 12 inches in length and 2 inches wide; fine texture
Flowers: Heads are very flat and solid, up to 4 inches
across; compound corymbs composed of pistillate ray flowers on the outer
edges of each floret and bisexual, usually yellow, disc florets only
1/8-1/4 inch across; on stems to 24 inches long. Long-blooming; species is typically white
but cultivar colors range from white to pink, rose, yellow, gold, red, or
orange and many fade into a different color range. Can be successfully dried and hold their
color. June-August
Seedheads: Brown, solid, and persistent through the
winter
Culture: Full sun, will thrive but become open in part
shade; average to lean or poor, infertile and well-drained soil; drought
tolerant once established and can be basically ignored. Cut back after flowering to rejuvenate
foliage and encourage repeat bloom; divide to control spread and keep center
from becoming open. Silver-foliaged hybrids remain in contained clumps and
rarely need dividing; may heave out of the ground and need resetting.
Uses: Groundcover in hot spots, naturalized gardens,
prairies and meadows; cut flowers, dried flowers (flowers hold their color
well); texture contrast.
Companions: Russian sage,
catmint, lilies, daylilies, coneflowers, poppies (spreading foliage will hide
bare spots left by this spring bloomer), ornamental grasses
Propagation: Terminal
cuttings or division before or after flowering
Cultivars: ‘Moonshine’
- a hybrid with upright gray-green foliage, non-spreading; yellow
`Paprika’ -
deep brick red-orange, fading to orange and gold
`Fireland’ -
deep crimson red, fading to pale red-salmon; 36” tall in flower
`Red Velvet’ - dark red, fading to
medium pink
`TerraCotta’ -
the color of a terracotta pot, fading to gold
`Summer Pastels’
- pale yellows, pinks
‘Snowsport’ -
pure white, very strong bloomer on good foliage
Other Species: A. filipendulina, A. ptarmica, A. serbica
Ornamental Onion
Allium senescens var. glaucum
Alliaceae
Form: Flattened mound that appears twisted; foliage
height 6 inches, flowering height to 12 inches; spread 12 to 18 inches from
bulbous base. The variety is superior to the straight species; look for the
distinct whorled pattern even in young plants
Foliage: Narrow, linear, twisted, grasslike blue-green
leaves in whitish basal sheath. Dramatic
because of uniformity of twisted appearance, and the foliage remains effective
during entire growing season. Customary onion smell when crushed; fine texture
Flowers: Globular inflorescence (umbel), 1 inch wide or
slightly larger, opens from a nodding bud to an upright ball on a leafless
stalk. The individual lilac or mauve
flowers are small with five tepals and very attractive to bees. August to September
Seedheads: Dried tan calyx filled with black seeds; can
be preserved but is not persistent in the landscape
Culture: Full sun to part shade; average to infertile,
well-drained soil. Standing water will
kill the plant. Carefree plant with few
pests or problems.
Uses: Edger, rock garden, cut flower, butterfly
garden.
Companions: coreopsis, penstemon, veronica,
snow-in-summer, thyme, ornamental oregano, lady’s mantle
Propagation: Division or separate bulbs and replant
Cultivars: `Blue Twister’ - more
distinct whorl in foliage; deep steel blue color
Mouse Garlic/Summer Beauty Allium
Allium angulosum `Summer
Beauty’
Alliaceae
Form: Strong upright clumps to a height of 18 inches
and spread of 18 to 24 inches
Foilage: Bright green, ¼ inch flattened blades with
rounded tips; evergreen or semi-evergreen in zone 6; very early to emerge in
spring; medium-fine texture
Flowers: Straight species has round globes (umbels)
consisting of tightly arranged hermaphrodite flowers (male and female parts in
a single flower); pale pink to lavender; up to 2 inches across on unbranched
stems; June to August. `Summer Beauty’
is sterile, and long-lasting. Alliums
are poisonous to dogs and cats.
Seedheads: Tan, persistent into early winter
Culture: Full sun to very light shade; well-drained
soil on the dry side. Clumps increase
slowly and rarely need dividing
Uses: Edger, attract pollinators, cut flowers,
grasslike texture.
Companions: Sedums, agastache, lambs ears
Propagation: Division
Contock Pussytoes
Antennaria parvifolia
Asteraceae
Form: Tiny
mat-forming groundcover not exceeding 4 inches in height; spreading by stolons
to 18 inches or more; prairie native
Foliage: Basal, dense, silvery gray foliage; each leaf
1 inch long or less; leaves resemble the tip of a paper airplane (spatulate)
arranged at 90 degree angles to one another; ever “gray” through the year; fine
texture
Flowers: Dioecious; (male and female on separate
plants); on upright stems to 6 inches;
rounded corymbs with papery scales that surround the “pussy toes” and
create the visual interest; April to May
Seedheads: Not effective; scales do not persist
Culture: Full sun; rocky, gravelly or sandy
well-drained soil; extremely drought tolerant once established. Do not provide supplemental water, especially
in areas of high humidity and high night time temperatures; and withhold
fertilizer
Uses: Rock garden, edger between steppingstones or
along dry paths, hot spots, grown more for foliage than for flowers.
Companions: thrift, thyme, small sedums, dianthus
Propagation: Spring division or seed
Other species: A.
neglecta, plainleaf pussytoes
A.
dioica, common pussytoes
A. plantaginea,
plantain pussytoes - Plains
native useful as an alternative to introduced silver groundcovers like
snow-in-summer (Cerastium tomentosum)
Wall Rock-Cress
Arabis caucasica
Brassicaceae
Form: Loose, casual mats form large basal clumps;
height 9 to 12 inches, spread 18 inches or more
Foliage: Softly pubescent, thickened, succulent leaves,
tufted, with obovate basal leaves and eared (auriculate) stem foliage with
sagittate (arrowhead) bases. Foliage is effective in winter as an ever-gray
mat, but deteriorates after flowering; medium-fine texture
Flowers: White, ½ inch wide, four-petaled, fragrant,
in racemes held on very short stems just above foliage; April to May
Seedheads: Not effective
Culture: Full sun to part shade; average to dry,
well-drained soil; tolerant of alkaline soils and competition with tree
roots. Shear after flowering to
rejuvenate foliage and eliminate tendency to become stemmy.
Uses: Walls, rock garden, groundcover, edger.
Companions: Lenten rose (in shade), basket-of-gold,
Serbian bellflower, epimedium, bigroot cranesbill
Propagation: Seed (will self-sow in favorable conditions);
cuttings taken immediately after blooming
Cultivars: ‘Snow Cap’ - very
large white flowers
‘Variegata’ - bold cream, white, or gold variegated foliage
‘Rokey’s Purple’ - outstanding
purple flowers
Seafoam Artemisia/Curlicue Artemisia
Artemisia versicolor ‘Seafoam’
Asteraceae
Form: Rather open, loose plant, with the stems
curling like waves. Height 9 to 12
inches; spread 18 to 24 inches. Slow growing
Foliage: Also curled, deeply dissected and pure silver
Flowers: Rarely flowers
Seedheads: Not effective
Culture: Full sun and dry to average, very
well-drained soil will produce long-lived plants. Over-irrigation, standing water, and heavy soils
are the death knell for this and most other artemisias
Does not need dividing or
pinching to maintain a pleasing habit.
Remove fallen leaves in autumn to avoid holding moisture on crown.
Uses: Rock garden, texture, hot spots, moon
garden.
Companions: penstemons, lamb’s ears, Missouri
Propagation: Division
Other Species: A.
frigida, fringed sage - native
Fendler’s Aster
Aster fendleri
Asteraceae
Form: Open, spreading mound, to a height and width
of 18 inches
Foliage: Narrow, alternate, light green to gray green,
leaves one inch in length; fine texture
Flowers: Pale lavender with yellow discs, ½ to ¾
inches across in loose panicles, September
Seedheads: Not persistent
Culture: Full sun, well-drained, sandy to loamy soil;
does well on rock ledges. Good drainage
is a must
Uses: Butterfly gardens, rock gardens, naturalized
areas
Propagation: Division, cuttings, seed
Cultivars: ‘My Antonia’ - a pure white release from the Nebraska
Statewide Arboretum
Basket-of-gold
Aurinia saxatilis
Brassicaceae
Form: Clumps spread to form large mats; older
plants become almost woody and in danger of heaving out of the ground; height 9
inches, spread 18 inches or more
Foliage: Silvery-gray with soft starlike (stellate)
pubescence, ½ inch wide, oblong-lanceolate or obovate with entire margins; up
to 5 inches long; medium-fine texture
Flowers: Bright yellow with four petals, each flower up
to 1/4 inch across. The
plants are covered by the rounded panicles which are long-lasting in cool
conditions. March to April
Seedheads: Not effective
Culture: Full sun and dry, well-drained soil is
essential; poor drainage or snow piles will kill this plant. High humidity causes plants to melt out, and
high fertilization causes it to flop. Shear after flowering for foliage and
form rejuvenation. Older plants may appear to have spread like a groundcover,
but the heavy mat of foliage is often lying on the surface rather than attached
by roots at the stems.
Uses: Walls, rock gardens, edger, hot spots.
Companions: catmint, rock soapwort, dwarf daylilies,
pineleaf penstemon, dianthus, thrift
Propagation: Seed, division, cuttings
Cultivars: ‘Citrina’
- lemon-yellow, slightly taller
‘Dudley
Neville’ - apricot-orange-yellow
flowers.
Other Species: A.
montanum
Plains Yellow Primrose
Calylophus serrulatus
Onagraceae
Form: Semi-woody plant with spreading habit, to a
height of 12 inches and spread of 18 inches
Foliage: Alternate, narrow, lanceolate, sharply
toothed, gray-green, each leaf 1/8 inch wide and less than 1 inch long, fine
texture
Flowers: Four-petaled yellow flowers ½ inch to ¾ inch
in diameter on stalks on ends of branches;
continue to form as branches elongate during season; eight yellow
stamens are prominent in center of blossom.
Flowers stay open during the day, unlike most primroses. May through
July
Seedheads: Not effective
Culture: Full sun; dry,
well-drained soil; intolerant of overhead watering or high humidity
Uses: Edger, low border, open groundcover.
Companions: Lavender, sedums, blue grama, penstemons
Propagation: Taproot makes this plant drought tolerant but hard to
divide; cuttings. Cut back hard only in spring, to live wood
Cutlivars: ‘Prairie Lode’
- extremely floriferous selection
Jupiter’s Beard
Centranthus ruber
Valerianaceae
Form: Broadly rounded, open form, to a height of 18
to 30 inches and a spread of 24 inches
Foliage: Blue-green, somewhat fleshy or
smooth-surfaced leaves, usually lanceolate and up to 3 inches long, are
opposite and sessile on long stems. The
margins are entire, sometimes with slight teeth. Medium texture
Flowers: Terminal clusters 2 to 3 inches wide in
branched cymes contain large numbers of pink to reddish pink to white flowers,
each only ½ inch long. The flowers are
fragrant, and borne over a long period, beginning in June and continuing into
September if deadheaded or pinched.
Seedheads: Not effective
Culture: Full sun to very light shade and well-drained
soils that are neutral to slightly alkaline will produce good plants. Fertile, moist soils will result in floppy,
open plants and eventual decline. Cut
back after bloom to encourage repeat flowering and remove seedheads, which will
happily produce large numbers of offspring.
Uses: Provide
scale at the top or base of rock walls, cut flowers, naturalized areas.
Companions: sun rose, lavender, dianthus, rock cress.
Companions: sun rose, lavender, dianthus, rock cress.
Propagation: Seed or division
Cultivars: var. ‘Albus’ – white
‘Pretty Betsy’ - deep rose
Ball Cactus/Pincushion Cactus
Coryphantha vivipara
Cactaceae
Form: A perfect round pincushion, to a height and
spread that rarely exceeds 3 inches
Foliage: None.
The stems are highly modified to form the rounded ‘pincushion,’ which is
covered with cylindrical tubercles.
Sharp brown spines punctuate each tubercle, and the plants are made more
dangerous by additional gray or white spines around the brown ones.
Flowers: Red to reddish-violet, up to 1 ½ inches
across, with many narrow petals ending in pointed tips and surrounding
yellow-orange anthers. May to June
Seedheads: Seeds are bright red, like beads
Culture: Full sun and dry, well-drained, sandy or
rocky soil.
Uses: Rock garden, hot spots.
Companions: skullcap, short native grasses, poppy mallow,
thyme, roundleaf horehound, dianthus
Propagation: Division, seed
Purple Hardy Ice Plant
Delosperma cooperi
Aizoaceae
Form: Mounds of succulent foliage 6 inches tall and
24 to 36 inches wide
Foliage: The oblong or linear leaves are cylindrical,
glossy green, and covered with little white flecks that look like ice. Individual leaves are 1 to 3 inches long and
up to ¼ inch wide. Not reliably
evergreen above zone 7, unless given ideal conditions. The foliage turns bronze-red in the
fall. Medium-fine texture
Flowers: Brilliant red-purple flowers up to 2 inches
wide with fringed, daisylike petals cover the plants in early summer.
Seedheads: Not effective
Culture: Full sun to very light shade and perfect
drainage are required by hardy ice plants.
Loamy soils will work as long as the drainage is good. The plant may be short-lived in zones 5 and
6.
Uses: Walls, hot spots, narrow sites between
sidewalk and curb (be careful of snow on the crown in the winter). Companions:
sun rose, basket-of-gold, roundleaf horehound, dianthus
Propagation: Division, cuttings
Other
species: D.
nubigenum, Yellow hardy ice plant - is similar in form and
structure. It is shorter, with
yellow-orange flowers. It is hardy to
zone 4. There are many other ice plants
available now; most need further testing in Nebraska
Cheddar Pink
Dianthus
gratianopolitanus
Caryophyllaceae
Form: Dense rounded mats or cushions 2 to 6 inches
tall and up to 18 inches wide; large variation in cultivars. Stems do not root
well but density gives plant a groundcover-like function
Foliage: Opposite, needle-like in appearance but soft
to the touch, lanceolate and entire.
Very narrow, and ½ to 2 inches long; blue-gray-green and effective well
into winter; fine texture
Flowers: Single or in pairs on short stems, each
spicily fragrant flower 1 inch in diameter with five notched petals. Color
range includes rose, pink, white, dots, spots and bicolors in cultivars. May to September if deadheaded
Seedheads: Not effective
Culture: Full sun and average to dry, well-drained
soil; tolerates slight alkalinity. Shear after blooming for dense growth and
rebloom through most of the summer
Uses: Walls, rock gardens, edgers, fragrance,
cutting flowers.
Companions: rock rose, catmint, red valerian, snow-in-summer, thyme, woolly yarrow, small veronicas
Companions: rock rose, catmint, red valerian, snow-in-summer, thyme, woolly yarrow, small veronicas
Propagation: Seed (seedlings will be variable), terminal
cuttings
Cultivars: ‘Spotty’ and ‘Double
Spotty’ - red and white bicolors, developed by the Fleming Brothers, Nebraska
‘Dottie’ - white with maroon eye, also Fleming Brothers, short
‘Oakington’ - double pink, very tiny flowers and foliage
Other Species:
D.
x allwoodii, D. knappi, D.plumarius, D. deltoides
Rabbit-brush
Ericameria nauseosus var. nauseosus
Asteraceae
Form: Shrubby, rounded upright plant with
semi-woody stems; height and spread to 36 inches. Will become larger if left undisturbed. A plant for the west.
Foliage:
Glabrous, pubescent; entire plant appears softly gray-green, with twigs also
covered with soft down; fine texture but medium form
Flowers: Held
in terminal clusters of various forms, 5 disk florets on each flower head,
yellow, with no rays; individual flowers small but numerous; June to November
Seedheads: Not effective, but stems of plant retain
substance and silver appearance through winter
Culture: Full sun, average to poor soil of low
fertility; tolerant of alkaline soils; extremely drought tolerant and must have
excellent drainage; suffers in areas with high humidity. Cut stems to 6 inches above ground after last
frost; difficult to move in large sizes.
Uses: Shrublike plant in naturalized gardens,
prairies, hot spots.
Companions: Russian sage, yarrow, narrow-leaved puccoon,
small soapweed, artemisia, gayfeather
Propagation: Cuttings
Myrtle Spurge/Donkeytail Spurge
Euphorbia myrsinites
Euphorbiaceae
Form: A rather uniform mass of gently curving
‘tails,’ with stems packed tightly enough to hide the ground beneath the plant;
height 6 to 12 inches and spread to 18 to 24 inches
Foliage: Thick, fleshy unbranched stems are clothed in
equally fleshy, glaucous blue-green leaves, closely spiraled around the stem to
appear whorled; each sessile leaf is obovate to obovate-oblong and less than 1
long; with a short, sharp tip (mucronate).
The foliage persists through winter; medium texture.
Flowers: Unisex, greenish, surrounded by pale yellow
bracts in umbels 2 to 4 inches wide; showy against foliage. April to May
Seedheads: Not effective, but bracts remain showy for a
long time
Culture: Full sun to light shade; average to poor,
well-drained soil amended with gravel, sand, or other coarse materials. Poor drainage and overabundant moisture will
kill the plant. Cut back and pull stems
that have rooted to control spread.
Uses: Unusual texture and persistent foliage make
it a good specimen in the border, rock gardens, walls.
Companions: Serbian bellflower, bergenia, rock cress,
dianthus, rock rose
Propagation: Seed, division, cuttings
Baby’s Breath
Gypsophila
paniculata
Caryophyllaceae
Form: Rounded, as wide as tall to a height and
spread of 24 to 36 inches; deep taproot
Foliage: Opposite, narrow gray-green leaves with entire
margins and chalky surface. Leaves are
up to 4 inches long and densely cover the slender stems; fine texture
Flowers: Cloud of tiny 1/16 inch white flowers in
loose panicles covering the plant. In
flower, the height and spread may exceed 48 inches; May to August or longer if
continually picked
Culture: Full sun and average loamy or sandy-loam soil
with extremely good drainage. Chalky or
alkaline soils required for best performance; will not succeed in heavy
clay. Do not apply overhead water. Resents disturbance once established
Seedheads: Not effective, but flowers dry well
Uses: Cut flower, dried arrangements, texture in
border.
Companions: pincushion flower, knautia, veronica, salvia,
goldenrod, asters, nearly any perennial that provides texture contrast
Propagation:
Terminal cuttings; difficult to
transplant
Cultivars: ‘Bristol Fairy’ - double, the old standard for cutting flowers and larger than the
species. It is a repeat bloomer if
sheared after the first flush
‘Perfecta’ - larger double flowers, more vigorous habit than
‘Bristol Fairy’
‘Rosea’ - stronger pink than the species
Other Species: G. oldhamiana, Oldham ’s baby’s
breath - larger, more open, blooms July to September
G. repens ‘Alba,’ Creeping
Baby’s Breath
Common Sun-rose/Rock Rose
Helianthemum
nummularium
Cistaceae
Form: Mounded with trailing flowering stems;
sub-shrub habit with woody base; height to 12 inches and spread 18 to 24 inches
Foliage: Beautiful, opposite evergreen (ever-gray)
leaves 1 to 2 inches long and less than ¼ inch wide; entire margins. Fine texture
Flowers: One inch wide, very uniform, crinkled and
papery like tiny single Iceland
Seedheads: Not effective
Culture: Full sun in average to dry, well-drained
soils, including those that are sandy loam or gravelly. Plants tolerate alkalinity. Poor drainage, standing water in winter, and
high fertility will kill the plant.
Shear in early spring and after flowering to promote good side branching
and dense growth. Do not place in locations
where the plant will be exposed to dessicating winter winds, or provide a
protective mulch.
Uses: Rock wall, rock garden, edger.
Companions: dianthus, roundleaf horehound, red valerian,
rock cress, thyme, thrift, lavender
Propagation: Division, softwood cuttings in spring
Cultivars: ‘Raspberry
Ripple’ - bicolor, more upright
‘Wisley
Pink’ - soft, warm pink
Hybrid Daylily
Hemerocallis x
Liliaceae
Form: Arching clumps from stout, fleshy, fibrous
root system; height and spread vary with cultivar from dwarf (6 inches or less)
to over 36 inches; flower scape can exceed 5 feet
Foliage: Long, linear leaves, 18 to 24 inches long and ¾ inch to 1 ½ inches
wide, bright green; medium texture
Flowers: Three petals and three sepals, varying in
size from 2 to 6 inches long depending on cultivar; 5 to 9 attached by pedicels
to a long, branched scape held above foliage. Colors include orange, yellow,
bronze, red, purple, peach, pink; and hybridization has resulted in contrasting
center eyes in green, yellow, gold, brown, purple, pink or white; ruffled
petals; tetraploid performance; repeat bloom.
May to October; new cultivars are reliable repeat bloomers
Seedheads: Not effective. The pod is a three-part, dehiscent brown
tube.
Culture: Full sun to almost full shade (the foliage is
a workable groundcover but bloom is reduced); All soil types, as long as
drainage is good competes well with tree roots. May be susceptible to aphids
and thrips if overly stressed. Also may
decline in periods of extended heat and high humidity, but can be rejuvenated
by cutting the foliage to 6 inches and providing regular water. Remove scapes
after bloom for a tidier appearance.
Divide if flowering is significantly reduced.
Uses: Edger, groundcover, uniform texture, hot
spots, specimen, mass.
Companions: Bulbs (daylily foliage hides dying bulb
leaves), Russian sage, coneflowers, butterfly milkweed, catmint, asters,
boltonia. If used in areas of critical
winter visibility, surround with plants with some seasonal interest—daylilies
die completely to the ground
Propagation: Division nearly any time; almost impossible
to eradicate once established because of tenacious, fleshy, fibrous root
system; each tiny piece will regenerate
Huge numbers of daylilies
from which to choose, including dwarfs, rebloomers, and even old-fashioned
straight species with exceptional fragrance
Cultivars: `Trophytakers’ - Darrell App’s newest hybrids
`Returns’
series - reblooming, with an ever-widening range of colors
`Fairy
Tale Pink’ - beautiful, huge (5 ½ inch)
sugar-pink blooms with ruffled edges, 24 inches
Other Species: H.
lilio-asphodelis, gum jum
Evergreen Candytuft
Iberis sempervirens
Brassicaceae
Form: Rounded mounds spread to become uniform
groundcover on a woody base; height 6 inches, spread 15 inches
Foliage: Small, dark evergreen, narrow, up to 1½
inches long and half as wide; fine texture
Flowers: Small, four-petaled and pure, startling white
against dark foliage. Individual flowers
are in a dense inflorescence, up to 2 inches wide and borne in lateral leaf
axils. Late March through May; rebloom
occurs in some cultivars
Seedheads: Not effective
Culture: Full sun to part shade, well-drained soil
(avoid standing water and heavy clay). Cut back hard after bloom to maintain
compact habit and vigor; shear in spring only every other year
Uses: Edger, groundcover, mat or accent in walls;
evergreen interest in border.
Companions: pincushion flower, blue grama, threadleaf
coreopsis, penstemons
Propagation:
Seed or vegetative cuttings
Cultivars: ‘Autumn
Snow’ - still the best rebloomer for the
Plains; up to 10 inches tall with larger flowers
‘Snowflake’ - larger flowers, deep satiny sheen
Iris
Iris x barbatus
Iridaceae
Form: Stiff, upright clumps spreading from thick,
fleshy rhizomes very close to the surface of the ground; height and spread
vary. Separated by size into dwarf (less than 15 inches), intermediate (15
inches to 28 inches) and tall (28 inches or taller); spread is between 9 inches
and 24 inches. Exact parentage varies
and includes many species.
Foliage: Basal fans of bright green, glaucous, sword-shaped
leaves; width varies with size category, but generally wide in comparison to
other iris like I. sibirica. Leaves
can be up to 1 ½ inches wide and 24 inches long; medium to bold texture. Although foliage should be removed in fall to
prevent spread of disease, it is effective if left in place. New leaves emerge in late winter or very
early spring.
Flowers: All floral parts are in threes: 3 falls
(outer segments) and 3 standards (inner segments); falls droop or are reflexed
and have a “beard” in the center; standards are upright, cupped at the base and
arching open at the top. Segments may be
frilled, wavy or almost lobed. Colors vary and include solids, shades and hues
of a single color, bicolors, or tricolors; beards are often contrasting. One or more flowers appear on each strong,
upright stem, but heavy rains and winds will destroy a planting overnight by
knocking the heavy flowers to the ground. May be very fragrant. May to June;
hybridization has resulted in some that rebloom in September
Seedheads: Not effective
Culture: Full sun to very light shade; loose soil with
excellent drainage and a neutral to alkaline pH. Many species of iris thrive in rock garden or
alkaline conditions. Overwatering or poor drainage can destroy a planting, as
can iris borer that leads to bacterial soft rot. Insecticide treatments need to
begin in early spring if this is a problem, and remove foliage in fall for good
sanitation. Remove spent flowers after
bloom. Divide iris in late summer if flowering is reduced; discard damaged
rhizomes and replant at the same depth as the original plant (the rhizome
should be at or slightly above the surface of the surrounding soil). Cut fans to 6 inches. Frequent division is
required to keep plants vigorous.
Uses: Old-fashioned flower of cemeteries and
grandmothers’ yards; beloved by some, maligned by others but definitely a plant
to provide structure and texture in the garden.
Borders, edgers, cut flowers.
Companions: Peonies, sedums, catmint, coneflowers,
asters, coreopsis
Propagation: Division after flowering until early fall; do
not purchase rhizomes until fall.
Replant immediately.
Hybrids: Too numerous to list
Other Species: Iris
cristata, crested iris - short native woodland garden species with shallow
rhizomes, with short, narrow standards and a bright yellow crest; very early
spring bloom;
Iris reticulata,
reticulated iris - very early, dark blue to purple and gold, small (2-4 inches
tall)
The newest, exciting
breakthrough in iris is the remontants, which are reliable rebloomers.
Lychnis Rose Campion
Lychnis coronaria
Caryophyllaceae
Form: Rough basal rosette with a foliage height of
8 to 12 inches and spread to 24 inches.
Flowering stems are upright, with an overall plant form that is a large
vertical clump.
Foliage: More silver than green with woolly
pubescence; leaves up to 5 inches long with entire margins; smaller and sessile
on flower stalk. Basal leaves are
slightly spatulate, and stem foliage is oblong and opposite. Stems are also pubescent, and the entire
plant appears frosted
Flowers: Single, on short branched stems from the
nodes, five-petaled,1 to 1 ½ inches wide
from swollen nodes. Flowering is very profuse and a shocking magenta color. Flowering stems may reach 36 inches from the
base. May to July; will rebloom if
deadheaded
Seedheads: Not effective
Culture: Part shade to full sun, loose loam or gravelly
soils and excellent drainage. Standing
water, heavy clay, and poor air circulation shorten the life of this plant. Not
truly perennial; biennial or short-lived but seeds profusely, especially into
pavement cracks or rocks. The white form comes true from seed and is
outstanding. Melts out in high moisture
or humidity
Uses: Accent, rock garden, evening garden, foliage
interest.
Companions: Russian sage, threadleaf coreopsis, small
ornamental grasses, sedum, asters
Propagation: Seed or spring basal cuttings
‘Alba’ - pure white
`Gardener’s World’ - striking
double flowered form, with deep old rose red flowers over a long period. Short-lived
Faassen’s Catmint
Nepeta x faassenii
Lamiaceae
Form: Loose rounded to slightly upright mounds that
become more dense with shearing; height and spread varies with selection, from
18 inches to 24 inches
Foliage: Opposite, very small, 1 to 2 inches long,
oval-elliptical on short petioles with truncate (straight) bases and scalloped
margins. Entire plant is very sweetly and distinctly fragrant; fine texture
Flowers: Small but profuse, usually forming long
racemes in the leaf axils. The lavender
to blue flowers have two lips, with two lobes on the upper and three on the
lower “landing pad” and darker spots toward the interior. May through June; will rebloom if sheared and
last until frost
Seedheads: Not effective. The plants are sterile.
Culture: Full sun to very light shade; average soil
with good drainage. Very susceptible to
high humidity and overwatering; single stems will turn brown and die, followed
by death of entire plant. Can also be
grown in dry part shade, where little flowering occurs but foliage will remain
strong and provide good texture and color contrast
Uses: Border, edger, mass, hot spots, rock gardens,
insect attractor.
Companions:
The blue and silver are good blenders with almost all other colors, including
warm oranges. Pineleaf penstemon,
coneflowers, coreopsis, sedum, small grasses
Propagation: Terminal cuttings or divisions, spring only
Cultivars: ‘Walker
Missouri
Oenothera macrocarpa
Onagraceae
Form: Decumbent (sprawling stems with tips curved
upright) from very deep taproot; late to emerge in spring and appears as bright
red tips at first; height 8 inches, spread 18 inches
Flowers: Huge, up to 5 inches wide, four papery pale
yellow petals in funnel form; close by mid-day but reopen in evening; June to
July
Foliage: Narrow, lanceolate, entire to 5 inches long
on long reddish petioles; entire, bright green in species but silvery and
narrower in subspecies
Seedheads: Four-winged, odd-looking tan pods nearly as
long as the flowers; persist until early winter
Culture: Full sun to very light shade; must have good
drainage in average to dry soils for best performance. Mark to avoid digging into plants before
dormancy break; prune back hard after bloom to remove floppy stems and
encourage new foliage
Uses: Edger, rock garden, hot sites, prairie.
Companions: catmint, Russian sage, asters, yarrow,
pineleaf penstemon, daylilies
Propagation: Fresh seed or division immediately after
flowering; may weakly reseed if pods are allowed to ripen; difficult to
transplant in large sizes
Cultivars: ‘Comanche Campfire” - discovered and named by Harlan Hamernik of Bluebird
Nursery, ornamental throughout the season, with bright red stems and petioles
persisting until frost
Other Species: O. caespitosa
O. berlandieri ‘Siskiyou Pink’
ssp.
Fremontii - more refined, more
silvery, stems distinctly red, flowers paler yellow; smaller plant overall
Bigroot Prickly Pear
Opuntia
macrorhiza
Cactaceae
Form: Dense, spreading colonies of jointed,
paddle-like stems, with one or more new ones growing out of older ones; height
6 inches, spread to several feet
Foliage: Rounded or obovate paddles, flat, bluish
green, up to 5 inches long and 3 to 4 inches wide. There are 1 to 2 inch long
spines in clusters; usually near the paddle margins; the small, hairlike spines
are actually the dangerous ones, detaching easily when touched; coarse or bold
texture
Flowers: Huge and showy, the papery, light yellow to
occasionally peach or pink petals overlapping and forming flowers 3 to 4 inches
across above older paddles. The reddish stamens and cylindrical style with
lobed stigma are also showy. May to June
Seedheads: Fruit is pear-shaped or barrel-shaped, smooth,
reddish, sweet, and ripe in September. Not persistent
Culture: Desolate, dry, sunny, well-drained gravelly
sites or average garden soil, away from small feet and hands. Do not provide supplemental water or
ferilizer.
Uses: Hot spots, rock gardens, traffic control,
edible fruit.
Companions: small soapweed, soapwort, roundleaf
horehound, donkeytail spurge, hummingbird mint
Propagation:
Seed or division of the paddles, which
will root where they fall
Other species: Opuntia
polyacantha, plains prickly pear
O. humifusa
Pineleaf Penstemon
Penstemon pinifolius
Scrophulariaceae
Form: Graceful, wand-like stems form a wide
v-shaped mound; height 18 inches, spread 24 inches
Foliage: Tiny, needle-like, dark green and nearly
evergreen, densely clustered toward ends of stems. Very fine texture
Flowers: Tubular, 1 to 1½ inches long and narrow,
reminiscent of a trumpet but with a characteristic flared and lobed lower lip.
Bright orange-red to scarlet; very prolific from May through July
Seedheads:
Culture: Full sun, dry, very well-drained soils; will
tolerate poor conditions and alkalinity.
Do not provide supplemental water.
Cut back to just above woody base in spring only. This is a very long-lived penstemon in a
genus not known for persistence
Uses: Hot spots, rock gardens, natural landscapes,
edger.
Companions: Missouri
Propagation: Cuttings, seed
Cultivars: ‘Mersea Yellow’
- reaches 12 inches by 18 inches
‘Shades
of Mango’ - combines orange, apricot, and
gold flowers
Mexican Hybrid Penstemons
Penstemon x mexicale
Scrophulariaceae
Form: Rounded mound of foliage, to a height and
spread of 18 inches; may reach 24 inches in bloom
Foliage: Opposite, glossy dark green, lanceolate, with
faint teeth
Flowers: Large, tubular, with distinct spots and
nectar lines. Flowering begins in June
and continues through September.
Seedheads: Not effective
Culture: Full sun to very light shade, loam to sandy
or rocky soil, very well-drained. Too
much water or poor drainage will shorten the already short life of this plant
Uses: Cut flowers, borders, hell strips and hot
spots, rock gardens.
Companions: ornamental grasses, sedum, ornamental
oregano, yarrow, Russian sage
Propagation: Tissue culture
Cultivars: ‘Pikes Peak Purple’ - is deep purple with white spots and guidelines
‘Red Rocks’ - is
cherry red
‘Sweet
Joanne’ - is Dale Lindgren’s release.
Extremely floriferous, clear pink flowers on clean, bright green shiny
foliage.
`Dark Towers
Ruby Cinquefoil/Himalayan Cinquefoil
Potentilla atrosanguinea
Rosaceae
Form: Rounded mounds of foliage, to a height and
spread of 18 to 24 inches
Foliage: Alternate leaves with three digitate leaflets
up to 3 inches long on long petioles.
The leaflets have toothed margins and are bright green with soft
hairs. Medium texture
Flowers: ½ to 1 inch wide, with five deep wine-red
petals with rounded, notched tips, surrounded by five green sepals and five
green bracts. Flowers are held singly on
long, sliim stems.
Seedheads: Not effective
Culture: Full sun and lean, well-drained soil are
required for best performance.
Cinquefoil also prefers cool night temperatures. Cut back after first flush of bloom to reduce
legginess. This may be a short-lived
plant in garden situations. Potentillas
are susceptible to spider mite damage.
Uses: Texture contrast, border, edger.
Companions: Garden salvias, ornamental oregano, daylilies
Propagation: Seed; division of hybrids
Cultivars: `Gibson’s Scarlet’ - more compact; better flowering
than the species.
Other Species: P. thurberi ‘Monarch’s Velvet’ - larger mounds, leaves have 5 to 7
digitate leaflets with distinct teeth; beautiful deep burgundy flowers
Rock Soapwort
Saponaria ocymoides
Caryophyllaceae
Form: Trailing, forming a broad spreading mound to
a height of 4 to 12 inches and spread of 6 to 12 inches
Foliage: Small gray-green leaves, to 1 inch long,
opposite, and varying in shape from spatulate to ovate-lanceolate; entire
margins. Fine texture
Flowers: Dark pink, with five rounded petals, the ½
inch to 1 inch flowers borne in open, casual clusters. The calyx looks like a swollen, half-inflated
balloon, and is covered with hairs. May
to June, with sporadic rebloom through the season
Seedheads: Not effective
Culture: Full sun to light shade; loose, well-drained
soil of average to low fertility. Poor
drainage or heavy clay will kill the plant, as will too much humidity or
overhead watering. Cut back after
flowering to encourage bushy growth and limit seed production.
Uses: Rock walls, edges, borders.
Companions: snow-in-summer, bergenia, dianthus
Propagation: Seed, cuttings, division
Other species: S.
x lempergii ‘Max Frei’
- very beautiful, and very touchy
Resinous Skullcap
Scuttelaria resinosa
Lamiaceae
Form: Small, mound-forming plant up to 6 inches
tall and 18 inches wide
Foliage: Opposite, less than 2 inches long and half as
wide, with very few shallow teeth; sessile or on very short petioles. Dark green and good-looking during the entire
growing season. Fine texture
Flowers: Tubular, with a small upper hood and large
lower landing pad, lobed or undulating, each flower up to ¾ inch long and
brilliant deep blue with white center spots
Flowers borne two per leaf node in axillary racemes, and in such
profusion that plants appear more blue than green when in bloom. May to June with sporadic rebloom
Seedheads: Not effective
Culture: Full sun, sandy to sandy loam soils with
average moisture; tolerant of drier conditions once established. Good drainage in winter is a must. Shear lightly after bloom if desired to
maintain dense form, although this management is rarely necessary. Allow plants to reseed.
Uses: Border, edger, hot spots, rock garden, natural
garden, hot spots.
Companions: dianthus, plains yellow primrose, blue grama,
cactus, small sedums, threadleaf and eared coreopsis
Propagation:
Other species: S.
scoridifolia ‘Mongolian
Skies’ - discovered by Harlan Hamernik of Bluebird Nursery and released
as a GreatPlants selection; blooms all summer
Orange Stonecrop/Kamschatka Stonecrop
Sedum kamtschaticum
Crassulaceae
Form: Spreading, rooting at the nodes, to form a
casual sprawling mass 4 to 6 inches tall (up to 9 inches in bloom) and 18
inches or more across
Foliage: Alternate, succulent in appearance and
variable in size and shape, up to 1 ½ inches long and wide. Leaves may be spatulate to almost linear,
with rounded teeth. Medium-fine texture
Flowers: Yellow up to ½ inch across, with 5 pointed
petals and 5 sepals surrounding 10 long yellow stamens. Flowers are clustered in a short-stemmed
cyme, usually 6 to 10 per cyme. June to July
Seedheads: Dark brown, star-shaped, and persistent, but
small and not overly showy
Culture: Full sun to part shade, nearly any soil as
long as it is well-drained. Plants will
become open in too much shade, in rich soils, and when given too much
water. Very drought tolerant. Plants that become leggy or open can be cut
back any time and new foliage will appear.
Uses: Open groundcover, rock gardens, hot spots,
walls.
Companions: bellflower, pussy toes, penstemons,
blanketflower
Propagation: Terminal cuttings, seed, division
Cultivars: ‘Variegata’ - with cream colored leaf
margins. Tends to revert
There are huge numbers of
sedums, many of them summer-bloomers. Most of the taller sedums are fall bloomers.
Hens and Chicks/Common Houseleek
Sempervivum tectorum
Crassulaceae
Form: Rounded rosettes ranging in size from less
than an inch (‘chicks’) to 3 to 4 inches in height and width; up to 12 inches
in bloom. The plant is stoloniferous,
and forms little colonies.
Foliage: Alternate, thick and succulent, with a
pointed tip, flat top surface, and rounded back; from 1 ½ inch to 3 inches
long; gray-green with purple to red tints in the margins and on the points; 50
to 60 leaves occur in each rosette; fine texture
Flowers: On odd curved stems covered with white
pubescence; the flowers are purple-red, and more of a conversation piece than
an addition to the landscape. Plants
rarely flower
Seedheads: Not effective
Culture: Full sun to part shade; poor, rocky,
well-drained soil, although they will perform adequately in garden situations
if good drainage is provided. Standing
water and high fertility will destroy the plants. Divide by removing the offsets when the planting
becomes too crowded
Uses: Rock garden, specimen, container
plantings.
Companions: dianthus, arabis, minor bulbs, pineleaf
penstemon
Propagation: Removal of offsets, seed
Other Species: There are many other Sempervivum species, differing in size, form, color…
Mother-of-Thyme
Thymus serpyllum
Lamiaceae
Form: Mat or groundcover from prostrate, slightly
pubescent stems; height 6 inches, spread 24 inches
Foliage: Tiny, opposite, sessile leaves clothe the
square stems; bright green when emerging, dusty green later in season. Fine texture
Flowers: Small but dense rounded terminal or axillary
clusters, lavender-pink. The plant
appears frosted with pink when blooming. Distinct fragrance to entire plant;
highly attractive to bees. May to June
Culture: Full sun, dry to average well-drained soil of
low to average fertility and a rocky or gravelly composition. Thyme cannot tolerate standing water at any
time. Semi-woody base; cut back hard to new growth in spring and dead spots
will usually fill in. Plants mush out in
high humidity or poor drainage; shear for regrowth after bloom
Uses: Walls, edger, among stepping stones, rock
gardens, butterfly gardens, fragrance.
Companions: Other herbs, sun rose, germander, wooly
veronica, threadleaf coreopsis, lamb’s ear, lavender
Cultivars: ‘Annie Hall’ -
pale pink flowers
‘Coccineus’ - deep green foliage, shorter, dark red flowers
Other Species: T. vulgaris - is the culinary thyme
T.
citriodorus, lemon thyme
Woolly Speedwell
Veronica incana
Scrophulariaceae
Form: Mat-former, to a foliage height of 12 inches
and spread of 18 inches
Foliage: Opposite, 1 to 3 inches long with pointed
teeth; covered with white tomentose ‘fur,’ which gives the entire plant a
silver or pale gray appearance. Leaves are
smaller and oblong toward the base, lanceolate higher on the plant, and persist
well into winter. Medium-fine texture
Flowers: Deep blue, ¼ inch long but clustered on short
pedicels into racemes up to 9 inches long held well above the foliage. The flowering stems curl and twist in too
much shade and high humidity. May to
June
Seedheads: Not effective
Culture: Full sun to very light shade; average to poor
soils with very good drainage. Poor air
circulation, standing water or poor drainage, soggy or heavy soils and high
humidity cause foliar problems and ultimately lead to the death of the plant.
Cut back after flowering to rejuvenate.
Uses: Rock garden, edger, moon garden, cut
flowers.
Companions: threadleaf coreopsis, Missouri
Propagation: Division, cuttings, seed.
Prairie Verbena
Verbena bipinnafitida
Verbenaceae
Form: Sprawling, decumbent stems from a mound of
foliage; height to 9 inches, spread to 24 inches
Foliage: Roughly pubescent, dark green, toothed;
medium texture
Flowers: Bright purple, ¼ inch across in terminal
clusters; June to October
Culture: Full sun; well-drained, sandy to loamy soils.
Tolerates a wide range of conditions, including clay and moisture
Uses: Edges, naturalized areas, berms of rain
gardens and bioswales
Companions:
Propagation: Division
Small Soapweed
Yucca glauca
Agavaceae
Form: Spiky and round at the same time, with the stiff
evergreen foliage forming a clump up to 24 inches tall and wide; flowering
stalks can reach 60 inches. Roots are
branched, horizontal, and becoming semi-woody with age
Foliage: Stiff, bayonet-like leaves up to 30 inches
long and only ½ inch wide. Individual leaves have sharp points, and margins
with white exfoliating fibers; finer texture and overall appearance than Y.
filamentosa. Medium-bold texture
Flowers: Raceme on a thick stalk up to 5 feet tall. Individual flowers bell-shaped or classic
flower-bud shaped, creamy white to occasionally green-tinged or pink-tinged, up
to 2 inches long with 3 petals and 3 sepals, tight against stem. May to July
Seedheads: Capsules, chambered with 2-3 rows of black
seeds. Not particularly effective
Culture: Full sun in dry, well-drained soils of sandy,
rocky, or loess composition. Less
tolerant of heavy clay or standing water.
Place in locations where it is to remain indefinitely—difficult to move
or eradicate
Uses: Hell strips, rock gardens, prairie, native or
naturalized locations, winter interest.
Companions: donkeytail spurge, short native grasses,
cactus, sedum, hummingbird mint
Propagation: seed, root divisions
Other Species: Y.
filamentosa
Yucca/Adam’s needle
Yucca filamentosa
Agavaceae
Form: Rounded, uniform clump to a
height and spread of 30 inches
Foliage: Evergreen
‘swords,’ up to 1 ½ inches wide and 24
to 30 inches long with a distinct midvein and pointed apex. Wider and less pointed than Yucca glauca,
with very few curled marginal hairs. The
cultivars may have MANY curled filaments
Flowers: Bell-shaped,
cream to very light green, pendulous in tall branched panicles that can reach a
height of six to eight feet. Each flower
is up to 2 inches long.
May to June
Seedheads: Dehiscent
capsules, each containing
Culture: Full sun to
very light shade; well-drained soils.
Tolerant of a wide range of conditions, including extreme drought and
heavy clay (with good drainage).
Standing water or fertile, poorly drained winter conditions will
diminish vigor. Also tolerant of salt
Uses: Architectural element; winter
interest, barrier
Companions: Purple
winecups, sedums, catmint, grasses
Cultivars: `Bright Edge’
Color
Guard’ - distinct variegation in gold and/or burgundy on foliage
