What Grows There :: Hugh Conlon, Horticulturalist, Garden Advisor, and Photographer

Shorter Version Of Six Landscape Shrubs

Posted by Hugh on June 11th, 2021

Sugar Shack™ Buttonbush (Cephalanthus occidentalis Sugar Shack™) – Full Sun (6+ hours), Part Sun (4-6 hours), Full Shade (up to 4 hours). 3 to 4 feet tall and wide. cut the size in half and added colorful red fruit and glossy foliage. Add in cool looking, fragrant white flowers and you’ve got a delightful plant that shines from spring to fall (zones 4-10).

Hummingbird Summersweet shrub (Clethra alnifolia ‘Hummingbird’) – native summer blooming shrub with showy, wonderfully fragrant flowers that attract bees, butterflies and hummingbirds; attractive, glossy dark green leaves set off pure white summer flowers. Plant it near the deck or patio to enjoy the sweet scent in mid-summer; extra large blooms with equally large individual florets; deer-resistant (zones 4-9).

‘Little Henry’ Virginia Sweetspire (Itea virginica ‘Little Henry’) – a lovely compact, late spring native shrub. Beautiful display of fragrant white flowers over 2-3 weeks; glossy green disease-free spring/summer foliage; stunning garnet-red in fall; deer resistant (Zones 5-9).

Pugster Butterfly bush (Buddleia x) – compact plant just 2 feet tall and 2-3 feet wide, large full flowers in three color choices: Pugster Blue®, Pugster Amethyst®, and Pugster Pink®. Full sized long-blooming true-blue or pink fragrant flowers from mid-summer into fall; no deadheading needed; drought tolerant; blooms attracts bees, butterflies and hummingbirds; deer and rabbit resistant (Zones 5-9).

Low Scape Mound® aronia (Aronia melanocarpa) – tough, low-growing native groundcover shrub, providing beauty from spring through frost (zones 3-9). It forms a low 12-24 inches high by 18-24 inches wide shrub and ground cover. Leaves are glossy green. In spring, it’s covered in hundreds of dainty white flowers, and in autumn, the leaves turn brilliant red to contrast with dark purple-black fruit. It thrives almost anywhere: cold climates and hot ones, wet soils and dry ones, sun and part shade.

Double Play® Candy Corn™ Spirea (Spiraea japonica Double Play® Candy Corn™) – an eye-catching 18-24 inch tall compact shrub; new leaves start out brilliant red, later orange, eventually summer foliage turns sunny yellow with new leaves emerging orange; rich purple flowers in late spring make this spirea the most flamboyant member of the Double Play® Series. (Zones 4-7).

Three Cool Sedges (Carex)

Posted by Hugh on June 6th, 2021

*Carex* ‘Everillo’ at NC Arboretum, Asheville, NC

Over the past decade Japanese Sedges (Carex spp.) have become popular in U.S. gardens. Uncertain which ones to plant – here are three that are easy to grow and require little maintenance. The following three clump-forming evergreen Japanese sedges flaunt arching, green and white variegated grass-like foliage. Tiny insignificant, brown flower spikes arise on long stems in summer. All three are hardy in zones 5-9.

‘Everillo’ (Carex oshimensis) is one of seven varieties in the Evercolor® Carex series. Plants form a cascading mound of bright, lime-green leaves that turn yellow-gold as they mature. More sun intensifies the yellow, while the foliage turns chartreuse with increasing shade. Plants average 12-15 inches high x 24 inches wide and elegantly bright golden weeping foliage.

1 Year old planting of *Carex morrowii* ‘Ice Dance’

‘Ice Dance’ (Carex morrowii) enlivens the landscape with vivid deep-green centers and creamy-white margins on half-inch-wide leaves. Ice Dance spreads via slow to medium growing rhizomes into a grassy groundcover. Plants average 10 – 16 inches in height and 18 – 24 inches in spread. As an added bonus, Ice Dance maintains its cool color in winter in mild growing zones and and is semi-evergreen in colder climes.

‘Feather Falls’ (C. oshimensis) is recognized for its fountain-like green and white variegated leaves that hold its rich green color over the coldest of winters. Feather Falls sedge is new in the marketplace and may be hard to purchase at this time. The plant is a standout either grown by itself or in mixed container on a patio or deck. Feather Falls grows 16 inches high and 24 inches wide.

These clump forming perennial sedges thrive in sun and or moderate shade. Plants don’t grow much when it is hot. Plants stay evergreen where winters are mild. As previously stated, no clipping is needed. However, a rough winter may injury the foliage; if so, clip back the plant accordingly.

Divide cool season grasses in spring or early fall. Plant sedges in spring, thru summer, but no later than early October so plants don’t heave out of the ground. Feed sedges with a slow-release fertilizer (Osmocote™ or Nutricote™) at planting time and in early spring. Irrigate during dry summer periods. Sedges are deer resistant planted in garden beds, borders, woodland gardens, and containers.

Growing Cosmos

Posted by Hugh on May 26th, 2021

Cosmos are native to Mexico. In the U.S. these old-fashion annuals bloom throughout the summer months and attract birds, bees, and butterflies to your garden. They produce colorful 2- to 4-inch wide daisy-like flowers that sit atop 3-5 feet tall slender stems. Cosmos make excellent cut flowers and dwarf forms are ideal in containers.

Annual cosmos grows in average well-drained soils and in partial to full sun. To avoid staking cosmos, tall varieties are best in full sun and in poor, fairly dry soils. Over-watering and over-fertilization can lead to plants with fewer flowers. Shelter cosmos from strong winds. Plant taller plants close enough for plants to support one another. Deadhead spent flowers to prolong bloom, but just enough flower heads for self-seeding.

Cosmos are low-maintenance annuals. Summer medium green leaves are deeply cut into threadlike segments. Floral colors range from red, pink, orange, yellow, white, and bi-colors. Cultivars feature single, semi-double or double flowers that range in height from dwarf (1.5 feet) to tall (6 feet). Floral heads may be flat or cup–shaped.

Two species are commonly listed in plant and seed catalogs. Cosmos bipinnatus come in pink, red, white, lavender, and bicolors. C. sulfureus come in yellow, orange and scarlet orange, and bicolors. Some varieties produce semi-double flowers. Deadheading dead or faded flowers encourages more flowering and better branching by pinching out the central shoots or stem tips. Some varieties grow very tall and may require staking. Mostly trouble-free, powdery mildew, stem cankers, aphids can be occasional problems.

Gardeners may opt to direct seed cosmos. For earlier flowering start the seeds indoors 6-8 weeks before the late frost forecast in your region. Cosmos self-seed readily. Either purchase seeds at garden shops or collect dried seeds late in the fall to sow next year. Know that seeds from hybrid varieties may not “come true” to the parent plant.

Varieties: C. bipinnata ‘Radiance’ (wine red), ‘Candy Stripe’, ‘Daydream’, ‘Sensation’, ‘Sunny Red’.

C. sulphureus ‘Bright Lights’, ‘Cosmic Orange’, ‘Lemon Twist’, ‘Klondike’ (orange).

Little Leaf Linden

Posted by Hugh on May 21st, 2021

Littleleaf linden

Littleleaf linden (Tilia cordata) is highly praised as an excellent urban shade tree. The species reaches 60 to 70 feet tall and spread of 30 to 40 feet. The foliage tolerates several urban pollutants. This durable tree is often utilized as a street and park tree because of its environmental adaptability. Two year old established are moderately drought-tolerant. It is easily grown in an average, well-drained, moderately acidic soil and in full sun (USDA hardiness zones 3 to 7).

Three-inch-long, shiny, dark green, ovate to cordate leaves persist through autumn. Fall leaf color turns pale yellow-green and is rarely remarkable. Tree blooms abundantly in June and the unusual, early summer flowers are both showy and fragrant. Small clusters of creamy yellow flowers form dangling cymes.

Flowers morph to become single winged nutlets through summer as they ripen in late summer. Flowers attract butterflies and bees and linden honey is highly rated.

Littleleaf linden seems not to be troubled by significant insect or disease issues. Injury from Japanese beetle feeding is often temporary and new aftergrowth masks leaf feeding. Pesticide applications over the first three years is recommended.

There are a number of cultivars available on the market, each with slightly different ornamental or size characteristics. Indigenous to Europe, all kinds of lindens are popular as tall hedges and windbreaks.

‘Chancellor’ grows more compact than the species, to about 50 feet high; the upright, habit of young trees becomes more pyramidal with maturity.

‘Greenspire’ is a shorter version of the species, grows 50 feet tall and develops a neat pyramid shape.

Shamrock® (T. cordata ‘Baileyi’) is similar to Greenspire, with a more open crown, spreading 30 feet wide.

Summer Sprite® (T. cordata ‘Halka’) is a compact selection with a rounded shape, reaching only about 20 feet high and 15 feet spread.

‘June Bride’ grows 30 to 45 feet tall and 25 to 30 feet wide; displays a slower growth rate with a dense pyramidal to oval crown.

Ashe Magnolia

Posted by Hugh on May 16th, 2021

Ashe magnolia (Magnolia macrophylla subsp. Ashei) is a small 10-20 feet tree with enormous leaf and flower sizes (zone (5)6-9). Anindividual white flower measures 6- 12 inches across with a purple blotch at the base of 3 inner petal-like tepals. Ashe magnolia blooms in late May – early June in Tennessee. Many of the white blooms may be hidden within the large tropical-like foliage.

Within the large leaf magnolia species, Ashe magnolia is the shortest — the runt of the litter. Its deciduous leaves are 10-16 inches long and 12+ inches wide. Leaves are wider near the tip than at the stem, green on the upper surface and whitish beneath. When fully open, the citrus-scented white blossoms reveal a purple blotch in center that is up to 6 inches long and about half as wide. Ashe magnolia blooms at an early age, usually when only 4-6 feet tall. A seedling may bloom as early as 3 years from seed.

Ashe magnolia is an understory tree, growing in day-long dappled sunlight or morning only sun. Allow Ashe magnolia plenty of room to grow, adequate light, and humus-rich, moist, well-drained soil. Don’t crowd other plants up around the tree. Lightly mulch around the tree to a depth of 3 inches. Over the active growing season, water the tree weekly over the 1-2 years until established.

Ashe Magnolia rarely needs to be fertilized unless growing potted. In a container, apply a slow release fertilizer such as Osmocote® or Nutrikote®. Life in a standard 5- gallon container is only 2-3 years and then it needs to planted in the ground or bumped into container 15 gallons or larger. For container-growing, dig a hole as deep as the container with a diameter to three times the width of the container. Fill the hole, water, and feed with a water soluble fertilizer like Miracle-Grow™ or Peters™.

Young Ashe Magnolia on East Tennessee State Univ. Campus in Johnson City, TN

Ashe magnolia does not thrive in hot and dry environs. The grand champion tree is 44 feet high in Montgomery County in Pennsylvania. In Florida, a tree grows in limestone-rich sandy or clay soil compared to a humus rich North Carolina clay soil. Sheltered sites are best since strong winds can shred the papery leaves and break the brittle branches.

Flower buds may be hurt by late-spring frosts in northern climes such as in New England. Prune in late winter or late summer to prevent bleeding of sap. Constructive pruning may be needed after storm damage and to maintain its desired tree framework.

Ashe magnolia is a tree that a plant collector will love. It is primarily available from a specialty e-mail nurseries. Request the tree’s seed provenance before purchasing. Select from a northern seed source if you garden in zones 6 or 7. The Florida Department of Agriculture lists the Ashe magnolia as endangered, due to its small population and restricted range.

Elephant Ears In The Garden

Posted by Hugh on May 11th, 2021

If gardeners want to add some tropical punch to the garden, elephant ears (Colocasia esculenta) and a close botanical cousin (Alocasia) are one of the first plants that I recommend (USDA hardiness zones 7b-10). Also called ornamental taro, plants take off and grow rapidly after spring planting (when all threats of freeze injury have waned). In the deep South, elephant ears are a garden fixture for 9-10 months before declining for a short winter dormancy nap.

Over the years I have grown the smaller (up to 6 feet tall) varieties in my small garden like ‘Black Magic (black matte finish), ‘Mojito’ (dark green /dark mottled patches), and ‘Tea Cups’ (cupped leaves that fill and spill water during rains).

For larger spaces Colocasia ‘Diamond Head’, ‘Black Coral’, and ‘Kona Coffee’ are striking for their dark leaf color and Colocasia ‘White Lava’ and ‘Maui Gold’ (chartreuse-gold blend) for their bright cheeriness. The largest Colocasia is C. gigantean ‘Thailand Giant’ that support leaves that grow 2-4 feet long.

Colocasia is a tender perennial that cannot survive winter months in many places. In USDA Zones outside of 7b-10, either use this tropical plant as an annual or dig up the tuber after the first frost and overwinter it in a cool dry area (possibly in dry wood shavings or peat) where the temperature does not fall below 45°F. The tuber should then be replanted again in late April. An easier method is to treat Colocasia as a container plant and move the container inside during the winter, given that you have space for such a large container.

Colocasia/Alocasia plants grow best in partial shade to partial sun. Full sun exposure, especially in warm areas, may damage these plants. They grow rapidly during the warmest days of summer. Feed plants with a slow-release fertilizer like Osmocote™ or Nutricote™ or a water soluble fertilizer like Miracle-Grow™ or Peters™. Don’t forget to irrigate –frequent watering, Plants prefer soils that drains well and does not stay soggy. In particular, Alocasia planted in very wet locations for extended periods is prone to root rot. Colocasia, on the other hand, grows best with full sun exposure and thrives in wet soil or in standing water.

Elephant ears can be grown in garden beds and in containers. Sources to buy include independent garden centers, mail order, and local nurseries.

Warning: Alocasia leaves are very poisonous plant. Keep the plant away from children and pets and call your doctor, or vet if someone or a pet ingests the plant leaves.

Mountain Laurels – A Native Shrub Many Gardeners Forget To Plant

Posted by Hugh on May 6th, 2021

Mountain laurel (Kalmia latifolia) is a U.S. native broadleaf evergreen shrub (USDA hardiness zone 5 – 7(8)). Whether you are hiking through area woodlands or driving through Biltmore Estates in Asheville, NC, flowering mountain laurels dominate the May-June landscape in Northeast Tennessee or Western North Carolina. Mature shrub sizes range from 5 feet (dwarf cultivars) to 12 feet in height and spread.

Over the past 30 years, mountain laurels have so improved, thanks to the breeding efforts of Dr. Richard Jaynes*. He has released several dozen cultivars, including dwarf forms and very colorful flowers. Some favorite varieties include ‘Carol’, ‘Sarah’, ‘Tinkerbelle’, ’Bullseye’, ‘Minuet’, and ‘Olympic Fire’.

Flowers open over a two week period beginning in mid-May here in the Southern Appalachian region (USDA hardiness zones 6 and 7). In the wild, mountain laurel tends to grow near a woodland clearing. In the garden, plant in a spot capturing partial day sunlight. Mountain laurel prospers a cool, moist, acidic (pH 6 or below preferred), compost-rich well drained soil. Established shrubs tolerate droughty soils after two years; otherwise, apply 2-3 inches of pine bark or pine needle mulch. Avoid exposure to high wintry winds.

Pruning is best performed within a few weeks after flowering is finished. Prune to shape, to limit shrub height and width, and to remove dead or diseased twigs and branches. Feeding shrubs with an acidic water soluble fertilizer such as Miracle-Gro®, Hollytone® or Schultz® spurs new growth and flowering for next spring.

Mountain laurels tend to perform more reliably than rhododendrons. They grow poorly in poorly drained soils and are susceptible to lace bug damage on the spring/summer foliage. Roots are susceptible to Phytophthora root rot. Worth repeating, mountain laurels grow best on compost–rich acidic soil

*Dr. Richard Jaynes’ book: “Kalmia: Mountain Laurel and Related Species”, 3rd ed. (Timber Press). Used copies available from Amazon Books online for under $20..

Mountain laurel (Kalmia latifolia) is a U.S. native evergreen broadleaf shrub (USDA hardiness zone 5-7 (8)). Whether you are hiking through area woodlands or driving through Biltmore Estates, flowering mountain laurels dominate the May-June natural landscape in Northeast Tennessee and Western North Carolina. Mature shrub sizes range from 5 feet (dwarf cultivars) to 12 feet in height and spread.

Over the past 30 years, mountain laurels have so improved, thanks to breeding efforts of Dr. Richard Jaynes*. He has released several dozen cultivars, including those with dwarf forms and with highly colorful flowers. Some favorite varieties include ‘Carol’, ‘Sarah’, ‘Tinkerbelle’, ’Bullseye’, ‘Minuet’, and ‘Olympic Fire’.

Flowers open over a two week period beginning in mid-May here in the Southern Appalachian region (USDA hardiness zones 6 and 7). In the wild, mountain laurel tends to grow near a woodland clearing. In the garden, plant in a spot receiving partial day sunlight. Mountain laurel prospers a cool, moist, acidic (pH 6 or below preferred), compost rich soil which is well drained. Mountain laurels tolerate droughty soils after two years in an pinebark or pine needle mulched site. Avoid exposure to high wintry winds.

Pruning is best performed within a few weeks after flowering is finished. Prune to shape, to limit shrub height and width, and to remove dead or diseased twigs and branches. Pruning and feeding with an acidic water soluble fertilizer such as Miracle-Gro®, Hollytone® or Schultz® invigorates new growth and flowering the next year.

Mountain laurels tend to perform more reliably than rhododendrons. While several plant maladies are possible, mountain laurels grow poorly in poorly drained soils and lace bug damage on the spring/summer foliage. Their roots are susceptible to Phytophthora root rot. Plants grow best on compost–rich soil

*Dr. Richard Jaynes’ book: “Kalmia: Mountain Laurel and Related Species”, 3rd ed. (Timber Press). Used copies available from Amazon Books online for under $20..

New Compact Anise Hybrid Shrubs

Posted by Hugh on May 1st, 2021

Scorpio Anise Shrub (Photo from Dr. Tom Ranney, NCSU Mountain Research Lab, Mills River, NC)

Two new hybrid anise (Illicium) shrubs have been released by the NCSU Mountain Crop Improvement Lab in Mills River, NC. These new star anise shrubs, bred by Dr. Tom Ranney, are hybrids between Illicium floridanum and I. mexicanum. These native evergreen shrubs are low-maintenance and adapt to a wide range of growing conditions (USDA hardiness zones 6b-9a – hardy in zone 6a in a protected landscape area).

These new anise hybrids grow 3 feet high x 5 feet wide in either full sun to part shade and moist, well-drained, moderately acidic @ pH 6.0 soil. Anise shrubs tolerate shady, damp, and wet sites as well.

Anise shrubs have two main bloom seasons, first in April-May and bloom sporadically in September -November. Flowers are solitary and mostly outward-facing to nodding. Individual blossoms last 5-10 days and emit a slight anise fragrance.

‘Orion’ (White) and ‘Scorpio’ (Red) Anise Shrub (photo from Dr. Tom Ranney)

The evergreen leaves are smooth (glabrous), moderately shade tolerant, and highly disease and deer resistant. These dense, well-branched shrubs exhibit lateral branches ranging between 7.5 and 18 inches in length. Green fruits, less than one inch wide, ripen greenish yellow late in the year.

‘Scorpio’ bears large 1-3 inch wide bright burgundy red flowers that bloom in spring with secondary flowering in early fall. This moderately growing shrub is compact, 3-5 feet tall and wide along with handsome evergreen foliage.

‘Orion’ bears large 1-3 inch wide yellowish-white flowers with numerous strap-shaped, radial petals, averaging 22 in number. Blooms heavily in spring and sparsely in early fall. This compact 3-5 feet tall and wide shrub has handsome evergreen foliage.

Planting A Tropical Look In Your Temperate Garden

Posted by Hugh on April 26th, 2021

This summer, whether you garden in Florida or Michigan, you can enjoy the tropical look in your garden with these 5 leafy plants, which are classified as “foliage annuals” because they are hardy in zones 10-12.

Caricature Plant (Graptophyllum pictum) in its natural tropical habitat grows 6-9 feet tall, typically 4-5 feet tall in zone 7. It is renowned for its colorful variegated foliage.

Elephant Ears (Alocasia/Colocasia), aka taro, are tropical perennial herbs with huge green or purple, heart-shaped, prominent veined leaves (zones 7b-9). Best sited in moist, organically-rich soil and adjacent to pools, ponds, and other water features. Mulch and irrigate during dry periods.

Hardy bananas (Musa basjoo) are rated hardy to northerly zone 6 and tropical Abysinian banana (Musa ensete) are winter hardy in USDA Zones 10-11. ‘Maurelii’ (red Abyssinian banana) is loved for its lush green foliage splashed with maroon-red tints and reddish leaf axils. Both grow 6-10 feet tall in temperate areas. Propagate by division.

Tapioca Plant (Manihot esculenta ‘Variegata’) is grown for its attractive palmately, 3-7 parted lobed, bright green foliage with variegated yellow midrib veins. Also called bitter cassava, this milky-sapped tropical shrub grows 6-10 feet high. Leaf lobes expand to 3-8 inches long. Small, apetalous, greenish-white flowers in short terminal panicles bloom through the summer season. (Zones 8-9). Propagate by stem cuttings.

Canna – many varieties including ‘Pretoria’ (aka ‘Bengal Tiger’) – 4-6 feet tall plant with bright orange flowers atop lush green / gold veined leaves; ‘Australia’ – huge deep red flowers atop long, burgundy-black stalks with lush chocolate brown/ silver banded foliage; ‘Tropicanna’ – tangerine flowers atop striped red, pink, yellow, gold, and green foliage. Shorter seed-produced canna varieties are also available. Deadhead old canna blooms to force reblooming.

General Care: Tropical plants are best grown in organic-rich, moist, well-drained soil in full to partial sun. Some plants tolerate part shade. Fertilize plants regularly during spring and summer. Canna bulbs are extremely heavy nutrient feeders. Site plants to protect from strong winds which can severely tatter the large leafy foliage. No serious insect or disease problems if sited and properly cared for.

Tropical plants can be grown in the ground or in containers. They are overwintered indoors for winter dormancy @cool 40°F or grown inside a heated greenhouse. Vegetative divisions or cuttings may be started in the fall.

Annuals To Plant In 2021

Posted by Hugh on April 21st, 2021

I spend spring, summer, and fall months visiting public gardens mostly in the eastern and southeast U.S. (Ohio/Pennsylvania south to Florida with camera in hand). I get ideas of new flowers to plant in my garden next year. Here are five flowering annuals that caught my attention.

Begonia ‘Canary Wing’ – this golden leaf plant along with bright red flowers lights up any shady patch in your garden. Canary Wing is a upright/mounded begonia with golden-to-chartreuse leaves and bright salmon red flowers. Leaf scorching, curling, and/or reddening of the foliage is a sign that ‘Canary Wing’ is receiving too much light.

Catharanthus (Vinca) ‘Kawaii Soiree’ bloom non-stop from spring planting to first frost in autumn. These compact growing annual vincas grow 6-10 inches tall and 12-18 inches wide and perform best in well-drained, humus-rich garden soils or in containers. Six colors in these compact growing vincas are available and more colors are coming: white, pink, coral, lavender, peppermint, red, and light purple. In general, vincas despise cool wet soils.

Gomphrena ‘Truffula™ Pink’ bloom nonstop from the first day after planting and fill their spot in the garden with a hot pink flowers until hard frost. Truffula^™ Pink performs best in hot, humid climates where it blooms all season long. Approximately 22-26 inches tall and wide, the blooms make ideal cut-flowers with a long vase life.

Henna Coleus (Plectranthus scutellarioides ‘Balcenna’) is noted for its serrated foliage. This tender perennial boasting chartreuse to copper-pink leaves complemented by dark burgundy undersides. attractively toothed, chartreuse to copper foliage. Grows 14-28 inches high.

Rockin’™ Golden Delicious (Salvia elegans) – grown for its great yellow-green (chartreuse) foliage. Grows 12-24 inches high and 15-30 inches wide. The more sun the foliage receives, the brighter the chartreuse color. Leaves may sunburn in very high light. In areas with strong sun this plant may benefit from afternoon shade. In northern areas it is valued as a foliage plant only. Red flowers arrive in late summer in zones 6 and points south. It is exceptionally heat and humidity tolerant and reliably hardy in the southeast U.S. (Zones 8-11). Golden Delicious is resistant to downy mildew resistant.