New England Asters

Symphyotrichum novae-angliae (aka Aster novae-angliae)

Appearance
Bright purple daisies with contrasting golden yellow centers adorn these shrubby perennials from August until October. Growing to four feet high and wide, the plants tend to sprawl unless staked. Stems bear long, lance-shaped leaves of dull green. Numerous cultivars have been developed with a wider range of flower colors, including pinks, fuchsia, and lavender.

Culture
As their name implies, New England asters are native to damp thickets and meadows of the northeast. They do well in Colorado as long as they have amended soil and regular irrigation. Don’t keep the ground soggy, however, as that encourages infection by fungal diseases. Plant purchased seedlings or rooted cuttings in full sun. Larger areas may be direct seeded in fall; cold winter temperatures are necessary for germination to occur. Pinch back stems early in the season to promote branching, but stop when buds begin to form in mid-summer.

Landscape Use
Their medium height and less-than-ideal foliage makes New England asters perfect for the middle of a perennial border. Try pairing them with other late bloomers with similar watering requirements. Tall sunflowers (both annuals and perennials) make a lovely backdrop, while goldenrod contrasts in color and form. Combining purple asters with ornamental grasses in copper and russet tones is especially pleasing.

Article and photo by Leslie Holzmann, Colorado Master Gardener.

 

Rabbitbrush

Bees and butterflies love the bright flowers.

Rubber Rabbitbrush, Chamisa
Chrysothamnus nauseosus

Appearance
With intense sulfur-yellow flowers covering its gray-green foliage, blooming Rabbitbrush demands to be noticed. Flowers last from August through October, with the seed heads providing interest all winter. Branches rising from a woody base form bushes up to 5 feet tall and wide. When not in bloom, the rounded crown and muted foliage impart a subtle, natural appearance to the garden.

 

Sneezeweed

Helenium hyb.

Appearance

Why would you grow a flower called Sneezeweed? Picture a striking, three-foot high perennial covered with 2 – 3 inch daisy-like flowers of yellow, orange, red, rust, and copper. The leaves are six inches long, lance-shaped and dark green. Plus, the name actually comes from the use of the dried leaves and flowers as snuff; the pollen is unlikely to cause hay-fever. On the other hand, continued contact with the plant can cause an allergic reaction, so it’s wise to use gloves. Also, the plants are bitter and toxic, so keep them away from small children and pets.

 

Sunflowers

(Helianthus annuus)

Appearance
Towering overhead, sunflowers may resemble their namesake, but their name actually comes from their ability to keep their “face” turned toward the sun as it moves across the sky. Everyone recognizes a conventional sunflower with its huge dark disk surrounded by yellow petals, set atop a sturdy stalk that may reach over eight feet in height. Newer cultivars, however, may not be so familiar. Breeders have developed shorter plants (as low as two feet) and an expanded palette of hues ranging from mahogany through orange to lemon yellow, white, and even a soft rose. Many types sport more than one color.

Cultivation
Sunflowers are easily grown from their large seeds, making them an excellent choice for a child’s garden. Pick a site that receives full sun, and amend the soil with plenty of compost. Sow around mid-May, covering seeds with a half inch of fine soil, and keep the ground moist until they sprout. Plants prefer regular irrigation, but can handle some drying. Mulch to keep the soil evenly damp and to reduce weeding.

 

Cupid’s Dart

(Catananche caerulea)

Description
Cupid’s Dart comes to Colorado from Europe, where its historical role as an ingredient in love potions gave rise to its common name. Clumps of slender gray-green leaves grow about a foot tall and wide. Wiry stalks extend past the foliage, supporting a myriad of striking periwinkle-blue flower heads, each set off by papery bracts behind the petals. If left to mature, the two inch blooms turn into attractive seed heads that last all winter.

Cultivation
Thriving on benign neglect, Cupid’s Dart requires full sun and excellent drainage. Provide supplemental water during prolonged dry spells. Although this is a short-lived perennial lasting about three years, it is easy to propagate. Plants may be divided in early spring, or started from seed. Seedlings started indoors in March will bloom their first summer. Place seeds in the freezer for several weeks prior to sowing. Removing faded flowers will prolong bloom.

Landscape Use
Its xeric qualities make Cupid’s Dart an ideal plant for low-water gardens. The lavender-blue flowers combine especially well with orange-yellow butterfly weed (Asclepias tuberose) or torch-lily (Kniphofia).  Use it as a temporary filler among slower-growing shrubs, where its short lifespan is an asset. The flowers can be used in dried arrangements.

Article and photos by Leslie Holzmann, Certified Colorado Gardener.

 

Wall Germander

(Teucrium chamaedrys)

Appearance
Bees, hummingbirds, butterflies, and gardeners all appreciate the lovely purple-pink flowers of Wall Germander. Imported from the mountains of southwest Asia and Europe, this woody herb resembles a diminutive, flowering boxwood, growing about one to two feet high and wide. Germander has small, oval shaped leaves of glossy green. The short flower spikes appear in mid-summer and continue until fall. Their minty scent perfumes the air (and may attract the neighborhood cat).

 

Calibrachoa

Appearance
Imagine a petite petunia with intensely-colored, trumpet-shaped blossoms in shades such as magenta, violet, or copper. Flowers smother the slightly fuzzy, gray-green leaves from late spring until the first hard frost. Prolific flowering means that new flowers quickly replace those damaged by hail, a major asset in our area. Mature plants reach about eighteen inches in width and are less than a foot high. A relative newcomer on the garden scene, Calibrachoa has already gained a place of honor among annual flowers.

 

Horned Poppies

Red Horned Poppy – Glaucium grandiflorum (syn: G. corniculatum)

Appearance
Huge, eye-popping flowers, with silky petals in shades of yellow to red, are a great reason to grow these unusual poppy relatives. The cup-shaped blossoms are supported by short stems rising from a basal clump of silver-green leaves about a foot wide and high. (Some species branch more than others.) Seed pods sport spiny “horns,” giving the plant its common name. Native to the eastern Mediterranean, Horned Poppies are listed as noxious weeds in some states (happily, not Colorado). Interestingly, the plants contain the chemical glaucine, which is used medically (and rarely as a recreational hallucinogenic drug—not recommended).

Cultivation
Horned poppies are grown from seeds or started seedlings. While the seedlings will overwinter in mild areas (to USDA zone 6), here it’s best to start them in early spring. Choose a spot in full sun. Soil must be well-drained for these xeric plants. Lightly cover the seeds, which can take a while to germinate. Once plants reach blooming size, they will continue to flower until seeds are formed or until frost. Removing spent blooms prolongs flowering, but if you want more plants next year, be sure to let some seed pods ripen. Pick them and scatter the seeds where you want plants to grow next season. A pea gravel mulch will keep weeds in check, mitigate soil temperatures and moisture levels, and encourage self-seeding.

 

Common Yarrow

Appearance
Yarrow (Achillea sp.) might be common, but it’s still a worthy plant for Colorado landscapes. Plants form spreading clumps of dark green, finely cut leaves about one foot tall. Flat-topped clusters of tiny flowers that rise well above the greenery provide landing places for butterflies, which are attracted in large numbers. Blooms may be white, pale to golden yellow, or various pastel shades; ‘Paprika’ is a cultivar that blooms in the red color of its namesake. Native to North America, yarrows were used medicinally to stop the flow of blood from a wound, hence some older common names such as Soldier’s Woundwort, Staunchweed and Nosebleed Plant.

 

Perennial Sweet Pea (Lathyrus odorata)

Appearance
Perennial sweetpea is a lovely, old-fashioned flower—one that grandmother might have grown. The keeled pea blossoms, ranging from a blushed white to a deep rose pink, form a clump atop long stems. Lanky vines sport sparse foliage, but plenty of coiling tendrils with which they cling to any support. Bloom will continue from now until early fall if spent flowers are removed. If left to mature, the round, spiral pods will suddenly twist open, flinging their seeds several feet into the air, and sowing plenty of new vines in your garden.