Landscaping With Goldenrods

Goldenrods at Dawes Arboretum

Goldenrods (Solidago spp.) represent about 100 species of perennials that grow ubiquitously along U.S. roadsides, prairies, open woods, and riverbanks. (USDA hardiness zones 4-9). A small number of species are also native in South America and Eurasia. Goldenrods are grown for their bright yellow or golden flowers that form late in the summer. They are easy to grow, and the tiny yellow flowers are a bountiful source of nectar for bees and butterflies, including Monarchs; seeds are eaten by songbirds fall and winter.

Goldenrods grow in almost any soil that is well-drained and in full sun. Removing spent flower clusters will encourage more blooms. Deadhead the old spent flowers to avoid prolific self-seeding. Every 3-4 years, divide plants in spring or fall.

Showy goldenrod (Solidago speciosa) is an eye-catching selection with abundant tiny, bright yellow terminal flower clusters atop stiff, narrow-leaved, reddish stems; 2-3 feet tall starting in mid- to late-summer.

Wreath goldenrod (Solidago caesia), aka blue stem goldenrod grows 1.5- 3 feet tall on arching, glabrous, wiry, greenish-purple stems which are covered with a silvery-white waxy covering (zones 4-8). yellow clusters of tiny flowers  bloom along the purplish stem in early autumn. Lance-shaped, medium green leaves (2-5 inches long) are toothed with sharply pointed tips.

‘Fireworks’ rough-stemmed goldenrod (Solidago rugosa) is probably the most popular variety, 3-4 feet tall clump-forming plant is covered with stiff bright yellow inflorescences starting in early autumn, reminiscent of exploding fireworks. 

‘Golden Fleece’ goldenrod (S. sphacelata ‘Golden  Fleece’)  grows 18 – 24 inches tall and 24-36 inches wide forms showy sprays of golden yellow flowers starting in mid-September into October.. Its heart-shaped leaves are semi-evergreen.

Ultra-dwarf varieties:

·         Little Lemon® (‘Dansolitlem’) - light yellow flowers on ultra-compact (14 inches tall / 18 inches wide plants.

·         ‘Cloth of Gold’- deep yellow flowers on 18-24 inch tall stems.

·         ‘Crown of Rays’ - bright yellow flowers on 2-3 feet tall stems.

No serious insect or disease problems trouble goldenrods and are moderately deer tolerant. If summer weather is unusually wet or planting is too crowded, expect minor disease problems.

Coneflowers

'Showoff' Echinacea at Kingwood Center, Mansfield, OH

Coneflowers (Echinacea spp.) have undergone great improvements over the past quarter century. Varieties are now available in many color shades and plants flower for longer periods. Recently introduced cultivars also grow alot shorter. On the negative side, some hybrid forms have been disappointing, barely surviving 1-2 years in the garden.

For overall dependability, Purple Coneflower (Echinacea purpurea) is my #1 favorite for dependability (USDA hardiness zones 3-8). The species is native to most of the Eastern and Midwestern U.S. They bloom in July, August, and into September, their nectar-filled flowers attract  butterflies and bees, and their winter seed heads provide food for birds and other critters.

Yellow Coneflower (Echinacea paradoxa) is native to the Ozark region in Missouri and Arkansas. The yellow blooming E. paradoxa have been bred with E. purpurea. Flowering starts in June, and puts on a long show even as the petals fade. This species has a small geographic range due to habitat loss.

Pale Purple Coneflower (Echinacea pallida) are native from the central U.S. Petals tend to be long, narrow, and droopy along with washed out lavender color. Leaves and stems are particularly fuzzy. They bloom from June to July and grow in most U.S. gardens under proper care.

Tennessee Coneflower (Echinacea tennesseensis) are native the state, but their habitat has been in decline over the past half century. Only recently has it been removed from the endangered species list. This mid-summer bloomer grows 2 to 2 ½ feet tall.

Coneflowers perform best in full sun and within a low to moderate range of soil fertility. While good soil drainage and watering during prolonged dry spells are good practice. Keep in mind that most coneflowers establish deep taproots and resent constant irrigation and over-feeding. To insure winter survival, coneflowers should be planted before July 1st.

Inkberry Holly A Worthy Substitute For Boxwood

Ilex glabra 'Densa'

Inkberry holly (Ilex glabra), also called gallberry, is a slow-growing broadleaf evergreen shrub (USDA hardiness zones 4-9). Inkberry grows to 5-8 feet tall and, if not pruned, may spread by root suckers to form colonies. 

Inkberry is native  from eastern Canada to Florida, west to Louisiana.  The dark green glossy leaves (to 1.5” long) have smooth margins and are spineless. Foliage stays attractive in winter unless temperatures dip below 0 °F. Greenish white flowers appear in spring, but are mostly inconspicuous.

Inkberry grows in average, medium to wet, acidic soils and in full sun to partial shade. It is one of few holly species that tolerates wet soils. Inkberries are dioecious (separate male and female plants). Female plants need a male pollinator to produce black,  3/8 inch diameter, berry-like (drupe) fruits that mature in early fall and persist throughout late winter into early spring unless consumed by birds and other wildlife.

Inkberry holly is a popular hedging shrub that tends to grow faster than a boxwood. Prune in early spring before new growth begins. Plants generally need minimal pruning unless used as a hedge. Remove root suckers as they form. Many landscape cultivars do not root sucker as badly as species. 
Leading cultivars are 'Densa', 'Shamrock', and 'Nordic'

No serious insect or disease problems trouble inkberry hollies. Leaf spotting occurs in wet summers. Spider mites may appear, especially during dry spells. In high pH (alkaline) soils, foliar chlorosis (yellowing) may happen.

Mass or group several inkberry hollies as a shrub border, a low foundation planting. Species inkberries will naturalize in moist woodland gardens or near streams or ponds.

Honey derived from inkberry flowers is a highly-rated. It is locally marketed in certain parts of the southeastern U.S. Dried and roasted inkberry leaves were first used by Native Americans to brew "Appalachian tea" a black tea-like drink.

Growing Blueberries In Your Garden

Both highbush and rabbiteye blueberries (Vaccinium spp.) are hardy in most regions of the U.S. Hot humid summers are problematic for highbush varieties and extremely cold winters can be injurious for rabbiteye blueberries.

Blueberry bushes grow 8-15-feet tall, requiring annual pruning. The soil pH should be in the range of 4.2 to 5.5. Their dark green summer leaves turn scarlet red in the fall. Pale pink flowers appear in the spring followed by the berries which start out as pale-green and ripen to dark bluish-purple.

Blueberries are very shallow rooted and must be irrigated regularly over the growing season. Space blueberry bushes 5 to 7 feet apart with rows 8 feet apart. As a base mulch use fabric matt and cover it with an additional 3 to 4 inches of sawdust, wood chips or pine needles. 

Feed each bush annually with a slow release organic-based sulfur-coated fertilizer. A newly blueberry plant starts out with one ounce of ammonium sulfate to a maximum of 8 ounces of ammonium sulfate for a mature bush per year. Bushes reach full production in 5-6 years and should yield annually for 20-30 years.

For northern gardens (USDA hardiness zones 3-7), highbush blueberries ('Duke', 'Bluecrop', 'Bluejay', 'Jersey', 'Blueray' are favorite cultivars) are harvested.
In Southern gardens, rabbiteye blueberries (zones 7-9) yield best. Varieties include: ('Tifblue', 'Premier', 'Climax', 'Powderblue', 'Brightwell',  'Montgomery'). Consult the local Extension office for recommended blueberry varieties for your area.

Acclimated to southern climates (zones 6b-9), rabbiteye blueberries bloom in early spring and may be injured by late spring frosts. Varieties with a high chilling requirement may yield poorly in deep Southern areas.  Both kinds of blueberries require cross-pollination; a few varieties are  self-fruitful.

Birds love ripe blueberries as much as people do. Cover your bushes with netting to protect against birds during harvest time. Blueberries should be pruned annually.

Growing Pentas To Attract Pollinating Bees And Butterflies

Want to attract more butterflies to your garden this summer? Pentas (Egyptian starflower) (Pentas lanceolata) is what you should be planting. Pentas are one of the best pollinator-attracting plants around. Flower colors range from red, pale lavender, pink and white. 

Pentas blooms all summer long, even during the hottest weather conditions. The large clusters of star-shaped blooms attract butterflies, bees and an occasional hummingbird. These annual flowers perform well both in garden beds and in large containers. Keep plants deadheaded and remove any spent blooms to encourage constant flowering.

Pentas plants are annuals in most U.S. climates (zone 10 hardy). The overall habit of these plants is neat and compact. If plants get too long and woody, cut them back by one-half and feed them with a water soluble fertilizer such as Miracle-Gro™, Jacks™, or Schultz™. Tall leggy transplants should be tipped back to develop more branching.

Overall, pentas are very easy to maintain. Newer varieties have improved disease resistance and grow shorter, e.g. more compact in habit. Pentas are troubled by few diseases and should be inspected for insects like aphids (in cool springs) and spider mites (dry hot summer periods).

Pentas prefer to be planted in full sun and in moist, well-drained soil. Pentas will dry out in hot summers and should be irrigated weekly during these times.

Leading cultivar series are Graffiti™ and Kaleidoscope™ (compact growers); Butterfly, Starla, and Northern Lights (taller growing).