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

Native Sedum (Three-leaved Stonecrop)

Posted by Hugh on November 2nd, 2024

Three leaved Stonecrop (Sedum ternatum), aka mountain stonecrop, whorled stonecrop), is a small, spreading, Eastern U.S. perennial (USDA hardiness zone 4 to 8). In its natural habitat, this native sedum is found in damp sites along stream banks, bluff bases and stony ledges. Stonecrops are in the Crassulaceae family. Mountain stonecrop grows 2-6 inches high and spreads by creeping stems which root at the nodes. Stems break away and die in winter, leaving newly rooted plants separated from the mother plant.

May ’24 in Brookside Gardens in Wheaton MD

Mountain stonecrop features small, rounded, fleshy, succulent-like leaves (to 3/4″ long) grouped in whorls of three, giving rise to its common name “three leafed sedum”. Clusters of tiny white, star-like flowers (to 1/2″ wide) with purplish stamens appear on erect stems above the foliage in April and May.

Plant 6 to 12 inches apart in a site with partial to full shade in well-drained soil. It does tolerate full sun, seldom needs watering, and will grow in moist soils with good drainage. The plant tolerates shade and moist soils better than most other sedums as well as drought and heat, rocky and poor soils.

It is a low maintenance, easily grown groundcover ideal in average, medium, well-drained soils in full sun to part shade. Mountain Stonecrop matures to a 6-inch-high plant with a 1 foot spread and four-parted white flowers. Stems creep along the ground or over rocks, forming dense mats. A single flowering branch, 4 to 8 inches high, rises along with many shorter, leafier, non-flowering branches. Stems break away and die in winter, leaving newly rooted plants separated from the mother plant. Leaves tend to fall off easily; fallen leaves can be used to propagate new plants.

Mountain sedum (foreground) in shallow rocky soil

No serious insect or disease problems. Botrytis is an occasional problem. Although it spreads by creeping stems, unwanted plants are easy to remove with a hoe. Purchase plants at native plant nurseries.

Stems and leaves may be eaten raw when very young and tender. As stems and leaves age, but before the plants flower, the edible parts may still be eaten if they are briefly cooked. The sap can irritate the skin of some people and the leaves, eaten in quantity, can cause stomach upsets.

Temple of Bloom® Seven Son Flower

Posted by Hugh on October 21st, 2024

Seven-son tree with white petalled blooms in September at Kingwood Center, Mansfield, OH

Few woody plants can matched for year-round beauty of Seven son flower. Temple of Bloom^® is an outstanding selection from Proven Winners™ (PW) is a beautiful, easy to grow this deciduous small tree or large shrub. It grows 10 -20 feet tall and 6-10 feet wide. In spring, the handsome leaves emerge, each sporting dramatically deep veins that make the plant stand out in the landscape. As the season progresses, the leaves grow larger and develop a long, twisting tip. (USDA plant zones 5-9).

Temple of Bloom seven-son flower is just coming into its own as a landscape specimen in August. Large bud clusters of fragrant white flowers open that bees, butterflies, and a few hummingbirds. It is a good source of nectar for butterflies, esp. monarch butterflies and other insect pollinators in the fall. The flower show lasts for weeks into late September before the white petals fall gracefully to the ground. Days and a few weeks later, the floral green sepals (calyx) change to vivid dark pink (bracts). Neighbors will believe that it has bloomed twice different colors in the same year. With winter’s arrival, seven son’s elegant frame stands out, fully revealing its amazing light tan peeling bark.

Plant seven-son in a special spot in your landscape where it can be seen and appreciated year-round. Seven son flower is available in limited numbers at upscale garden centers mainly in the spring – early summer.

Seven-son flower asks for little care. This moderately fast grower thrives in a range of soils from poor to rich while preferring not to dry out completely. This member of the honeysuckle (Caprifoliaceae) family is not an aggressive self-seeder. It is not troubled by serious disease and pest problems.

This unique tree from China flowers twice in late summer and fall when most other plants are winding down. Its trunk and branch bark peels off in thin strips year-round, although this feature is especially noticeable in the fall and winter months. Tan bark exfoliates to reveal attractive brown inner bark, which provides good winter interest. Leaves are narrow, shiny, ovate-oblong and medium green. This plant, native to China, is rare and its wild populations are vulnerable to extinction. It is becoming increasing in popularity as an ornamental shrub, though it may be difficult to find.

Temple of Bloom® is a compact, early blooming selection of seven-son flower. The fragrant flowers appear in dense clusters from mid-summer into early fall, which lengthens the period of time the showy, pink calyces can be enjoyed.

Verticillium Wilt, a fungal pathogen that also damages Maples, Ash, Eastern Redbud, and Smokebush, can attack Seven Son Flower.
Suckers may be a frequent problem for young trees.
Seven Son Flower trees don’t tolerate extreme cold or heat. Seven-son Tree is currently facing the threat of extinction in China due to loss of the plant’s natural habitat.

Triggering Holiday Cactus To Bloom

Posted by Hugh on October 12th, 2024

Thanksgiving cactus at home with other house plants

Thanksgiving and Christmas cacti are not desert plants. They’re indigenous to the tropical rain forest environment in South America. Holiday cacti thrive in bright indirect sunlight along with other house plants. Set them near an east-facing window when indoors over fall and winter or shaded under trees outdoors in the spring and summer months.

Indoors, mist plants daily or set near a shallow tray of water for humidity. Holiday cacti do not tolerate dry soil and require regular watering. Overwatering is a huge mistake. The major symptom of too much water is leaf drop, leaf rotting, and spotting.

October’s shortening daylengths and 50-55° F night temperatures spur plants to naturally develop flower buds. Avoid overnight temps below 50° F. Moving the plant to an unheated garage and setting the plant in an east-facing window is usually adequate in plant zones 5b-7a.

Scheduling the holiday cactus is simple. In northerly climes, simulate flowering 6-8 weeks before Christmas, place the plant in a completely dark space in a cool temp room around 55° F dark period such as in a closet or garage to simulate a 6 week/12- hour night period. Some gardeners place a box over the poinsettia plant at night and remove it in the morning. Each and every day, do not interrupt the 12-hour night (dark) regime. Water your soil every 7-10 days. If you don’t recall when you last watered, DON’T. Wait another 3-4 days.

Inexpensive starter plant at a local garden center are great holiday gifts

A few weeks after the flowers have faded, prune stems back to encourage new growth. To propagate your Holiday cactus, cut off several at least 3-stem segments and place them into a small pot of potting soil. Bury at least one segment in the media and water. Mist the cutting(s) daily until they have taken root (usually in 4 to 6 weeks).

Fall Blooming Bulbs

Posted by Hugh on October 8th, 2024

Most fall-planted bulbs bloom in late winter or spring. Correct? Actually No. Some bulb species bloom in Fall. These seven (7) fall-blooming bulbs are planted and will flower weeks later. Most Important – bulbs should be planted in the early days of September. To assure blooming occurs in the current year, purchase bulbs and plant immediately when package arrives. All should be long colorful additions to your landscape.

Fall Colchicums at Kingwood Center in Mansfield, Ohio

Autumn Colchicum (Colchicum spp.), wrongly called “autumn crocus”) is not true crocus. In fact, it is not in the same botanical family. Colchicum belongs to the Colchicaceae family (formerly part of the lily family, Liliaceae), while Crocus is in the iris family (Iridaceae). Approximately 65 species of colchicums are found worldwide. Colchicums bloom in late August through October. They wait to produce their foliage in following spring. Each bulb (corm) have 3-8 leaves on shoots 8-14 inches tall. As the weather begins to warm in late spring and early summer, leaves and stems die back. Fall blooming last about 2 weeks and are usually light pink; some cultivars are white. Colchicums grow best in well-drained soils in full sun to partial shade. (Zones 5-9).

Autumn crocus (Crocus speciosus) is a small corm that grow 6 inches tall. The 6-7 inches tall goblet-shaped crocus flowers are violet blue to mauve colored. The late-blooming crocuses multiply (perennialize) readily. Autumn crocus also produces its foliage in early spring, then die back as seasonal temps warm. (Zones 5-9).

Saffron crocus (Crocus sativus) is probably the most known fall-blooming crocus. This is the plant that the spice saffron comes from. Plants grow 4-6-inches tall and have lilac-purple flowers that open a few weeks after autumn crocus. Each flower produces three reddish-orange stigmas that are harvested and dried to create saffron. Grow crocus in a sunny, well-drained soil in your garden. (Zones 6-9).

Ivy-leaf Cyclamen (Cyclamen hederifolium) grows 4-6-inches tall. Tubers produce pink to white flowers that are 1-2-inches long with swept-back petals from September into October. While the flowers are the main attraction, the mottled foliage is highly ornate. The ivy-like heart-shaped leaves have dark green centers bordered with lighter green and silver patterns. Plants produce leaves after it flowers. The foliage stays around through winter before going dormant in spring. Grow best in moist, well-drained, humus-rich soil and in partial to full shade that are high in organic matter. Be patient as young plants generate only a few flowers in the first 1-2 years, but well-established clumps produce lots more. (Zones 5-9).

Winter daffodil (Sternbergia lutea), also called “autumn daffodil”, are lovely crocus look-alikes that have bright yellow crocus-like flowers produced in September to October. Flowers are 1.5 inches wide, and flower stalks are typically around 6-inches tall. Its narrow, lance-shaped foliage may reach 12-inches in length and persist through the winter, especially in warmer climes; otherwise, dying back in fall. Sternbergias are essentially pest- and disease-free. (Zones 6-9).

*Sternbergia lutea* – photo by Brent Heath

Guernsey lily (Nerine spp) is spring-planted bulbs. It produces a stunning display of pink, red, or white lily-like flowers in September and October, a time when most other plants are finishing up. A cluster of strappy, glossy green leaves emerges in summer followed by 18-24-inch-tall bloom stalks which burst open with colorful wavy-edged flowers. Its exquisite six petalled blooms stand atop slender, sturdy stems. Native to Southern Africa, they thrive in full sun and well-drained soil. Nerines are excellent for cutting, singly or in groups, and grown in containers. Three species are N. bowdeni, N. sarniensis, and N. undulata. (Zones 8-10).

Toad Lilies Shine In The Autumn Garden

Posted by Hugh on October 3rd, 2024

Toad lilies (Tricyrtis spp.) are late season flowering perennials in the shade garden. Most summer perennials have finished blooming as their flower buds are just forming. They’re native to moist woodsy environs of eastern Asia and are botanical members of the lily (Liliaceae) family (USDA hardiness zones 5-9). When properly sited, toad lilies are long-lived and require little extra attention.

The plant name – “toad lily” – refers to the speckled flower colors. Flowers are borne in the axils of the leaves. Depending on species, plants grow 1.5 – 3 feet tall. Select star or bell-shaped spotted flowers in an array of colors. Many resemble orchid flowers.

Toad lilies prefer part to full shade, and moist humus-rich garden soil. Under ideal conditions plants need little or no fertilizing. Plants should be protected from wind particularly in hotter areas of the U.S. Otherwise, feed plants once or twice in summer with a water-soluble fertilizer such as Miracle-Gro™ or Jack’s™. Mulching keeps the soil moist and suppresses weeds. Divide roots of toad lilies every 2-3 years in early spring; space plants 18-24 inches apart.

Four species of toad lilies, T. hirta, T. latifolia, T. macropoda, and T. formosana are very popular; they produce abundant purple-and-white blooms on 36 inch and taller stems. Many new hybrid forms are finding their way into garden centers. ‘Miyazaki’ hybrids are known for their superior flowering, vigorous growth, hardiness, and disease resistance. T. hirta ‘Miyazaki Gold’ has gold-edged green leaves and ‘Moonlight’ has entirely golden leaves. T. macropoda ‘Sinonome’ and ‘Tojen’ have dark green foliage and lavender and white flowers; ‘Lightning Strike’ displays green and gold leaves and speckled flowers on arching stems.

No serious insect or disease trouble toad lilies; slugs and snails are occasional pests. Anthracnose leaf spotting may pop up in wet summers. If so, clean up all leaf debris and discard in late winter. Deer may or not eat toad lilies? Rabbits may also be troublesome.

To repeat: Site selection is highly important. Toad lilies excel in moist well-drained soils and an early to mid-morning sun-dappled shady garden spot. Irrigate during dry spells. The beauty and detail of the small flowers need to be visually appreciated close up. Snip flower stems for a autumn table arrangement.

American Beautyberry

Posted by Hugh on September 26th, 2024

American Beautyberry (Callicarpa americana), also called French mulberry, is a fast-growing deciduous shrub native to the southeastern U.S. It grows 4-6 feet tall and has an open branching form with arching branches. The genus name Callicarpa comes from Greek words meaning “beautiful fruit”. Starting in July, the plant bears clusters of small, pale pink flowers along the squared stems. These flowers attract lots of pollinators like butterflies and bees. Flowers develop into tiny drupes, a type of fruit, that become bright magenta as they mature in the fall.

The ovate to elliptic, oppositely arranged leaves are coarsely toothed; they range from 3-8 inches in length and 1-3 inches in width. The small, light pink to purple or blue tinged flowers are arranged in dense, axillary clusters along main branches in early summer and develop bright, lavender to violet ¼ diameter fruits in September. White-berried varieties are available.

Beautyberry is widely adapted to moist, well-drained soils containing lots of organic matter. It is not finicky as to soil type as long as drainage is adequate. Mulch first year planted shrubs to conserve soil moisture. Irrigate during prolonged periods of hot, summer drought to prevent early fall defoliation.

Optimum fruiting occurs in full sun, although beautyberry does tolerate part shade and do poorly in deep shade and is less fruitful. Prune in late winter to encourage more bushy, compact growth. Plants can be cut as far back as 1-2 foot from the base or maintain the natural open shape of the shrub. Remove any deadwood in spring.

This shrub is perfect for attracting wildlife to the landscape while offering a marvelous pop of color in the fall. Beautyberry requires little maintenance and can grow in full sun to part shade. The best time to plant this shrub is in the fall and winter. Try planting many together to create an attractive native screen or hedge. An unusual cold harsh winter may result in stem dieback, but pruning back damaged shrubs will regenerate vigorous new shoots. Summer flowering and autumn fruiting will be unaffected.

Beautyberry is relatively disease and pest free. A member of the mint family (Lamiaceae), Lamiaceae, the sap from crushed leaves of beautyberry can repel mosquitoes and biting bugs both on livestock and human.

Leaf spots are possible but usually not a serious problem. Green leaves emerge in mid-spring on upright arching stems. Clusters of small lavender pink flowers bloom during the late spring and early summer. Clusters of purplish to bluish berries size and color-up in August through October. A pink-fruited and several white-fruited forms are available (see below).

ts colorful fruits are edible to humans as well, although some may be quite astringent. Fruits can be processed into jellies and wine. Their amazingly beautiful fruits are also very valuable to many types of wildlife as armadillos, foxes, opossums, raccoons, squirrels, and deer as a source of food with high moisture content. Over 40 species of songbirds eat the fruits which may persist into early winter.

Shrub size and its loose open form relegates American beautyberry to the back of a shrub border. In large landscapes mass several beautyberry shrubs together for a maximum fall berry show and winter wildlife habitat.

Cultivars

‘Welch’s Pink’ blooms in late spring into early summer and form beautiful pink berries in September that last into winter; grows 4-6 feet tall and wide, smaller than the species; initially found in east Texas and rated winter hardy in zones 7-11. A winter damaged shrub in zone 6b should roar back from the ground in spring.

Pearl Glam® is a hybrid form in which one of its parents is C. dichotima. What sets it apart is its unique dark purple foliage, bright white flowers, and loads of orchid-pink berries in autumn; space-saving growth habit at 4-5 feet tall and 3-4 feet wide.

f. ‘Albofructa‘ produces white berries in the fall.

Obedient Plant – A Native Autumn Favorite

Posted by Hugh on September 20th, 2024

Obedient plant (Physostegia virginiana) is a member of the mint family (Lamiaceae), and like garden mint, it spreads easily by rhizomes and easily self-seeds; the plant is not “obedient” in behavior. It is called “obedient plant” because each tubular flower will, upon being pushed in any one direction, stays in its new position. It grows in sunny, wet poorly drained sites. Plant this pink or white flowering beauty in a rain or prairie garden. It is also known as “false dragon head”. (USDA hardiness zones 3-9).

‘Miss Manners’ Obedient Plant (*Physostegia virginiana*)

This native perennial blooms from July into late September obedient plant. Tubular, two-lipped pink (or white) flowers form in upright terminal spikes (each to 12-18 inches high) atop stems rising 3 to 3.5 feet high and 1 to 2 feet wide. Bees and butterflies love the blooms as well.

Obedient plant (the species) tends to seed-in and also spreads prolifically by rhizomes. The leading cultivar is a non-spreading form appropriately named ‘Miss Manners’. Its deep green, glossy foliage will please as will its snapdragon-like rose pink flowers. The seedling was chosen by Darrell Probst and is a shorter grower @2 to 2.5 feet high and 2 feet wide. Plants display a clumping habit with some secondary branching. Obedient plant promptly reblooms when deadheaded. Miss Manners tends not to seed-in and it grows on sturdy stems. ‘Summer Snow’ is a white flowering cultivar.

Full sun and/or low fertile soil is an ideal garden spot. Otherwise, plants tend to flop and require staking in light shade or in rich fertile soils. Prune back plants by half in late spring for increased branching and to minimize floppiness. Plants should be divided every 2-3 years to keep beds neat and not overcrowded.

Obedient plant has no serious disease or pest problems, and deer generally avoid it. In wet summers rust disease may be troublesome. Periodically, inspect plants for aphids and spider mites. Include flowers in floral arrangements as the flowers “obediently” hold in almost any position you desire.

Harlequin Glorybower

Posted by Hugh on September 11th, 2024

Harlequin Glorybower (Clerodendron trichotomum) is a rambling 15-foot-tall rambling shrub which can be easily shaped into a multi-stemmed 10-to-20-foot small tree. Glorybower shines in the late summer and early fall landscape. Its sweetly scented, very showy flowers attract the attention of gardeners as well as hummingbirds and butterflies. (USDA hardiness zones 7-10).

Where I garden in Northeast Tennessee (USDA zones 6-b and 7), glorybower is at its northern cold hardiness limit. An occasional harsh winter will bring on lots of pruning repair. here, some winters do not treat glorybower kindly. Significant reconstruction may be needed. Moderate pruning in late winter repairs most ills with fast growing glorybower looking great by summer.

Sweetly fragrant, white flowers smother the plant from July through August. Flowers are arranged in wide 6 – 9-inch clusters, comprised of individual white 1½ inch blooms and are borne on current season’s wood. Next up, in mid-September, the metallic looking topaz-colored fruits with beet red calyxes provide quite a show. Flowers are initiated on current season wood.

Foliage texture is bold with broad 4- to 9-inch-long dark green leaves providing cooling shade to a nearby deck or patio. Its pale-yellow autumnal leaf color offers little interest. Glorybower is rated disease, insect, and deer resistant. Expect to observe a few hummingbirds fluttering around summer flowers.

Glorybower grows in a moist well-drained average soil and in full to partial (minimum 6- hours) sunlight. A 2-year old established tree is only moderately drought tolerance and requires irrigation during long dry spells.

On a recent trip to Portland, Oregon, glorybower serves as a yard and street tree. Interesting fact: leaves when crushed emit a peanut butter aroma. Native of Japan and China this under-planted tree is sold primarily by on-line specialty nurseries.

Surprise / Resurrection lilies

Posted by Hugh on September 4th, 2024

The beautiful colorful large flowers of Spider lilies (Lycoris spp.) pop up overnight in summer (July and August). In the Southeast and mid-Atlantic states, Spider lilies are popular passalong plants. They are known by a number of colloquial names such as “surprise lilies”, “resurrection lilies”, “hurricane lilies”, “Equinox Lily”, and “naked ladies”. They are members of the Amaryllis family. Bloom time coincides with the summer hurricane season, hence the name “hurricane lily”. (USDA hardiness zones 6-10).

Bloom time is relatively short, their unique flowers are beautiful and are outstanding addition to almost any garden. Floral colors range from red to white to yellow. Flowers last 5-7 days, and decline. Bloom clusters may last two weeks or longer if protected from wind and sun. In Southeastern states, almost 2-3 months later, strap-like green leaves emerge in fall. In northerly climes, leaves emerge early the following spring and grow into late June and disappear.

Spider lilies prefer rich, well-drained and slightly alkaline soils and prefer a part sun/part shaded site. Plant bulbs 12 inches apart with the pointed end up and their necks peeking slightly above the soil surface in fall or early spring. If bulbs are planted too deep, they may not flower.

Spider lilies perform best with summer watering, but may resent being flooded. Their leaves and roots are toxic, so deer and rodents pass them by, Flowers attract butterflies, some bees, and an occasional hummingbird. They are relatively resistant to diseases and pests.

Over the years, numbers of blooms may decline which may be a sign of overcrowding. Divide and separate bulbs every 3-5 years. Carefully dig bulb clumps in late spring after leaves begin to decline or wait until after the summer blooming period when they are dormant.

Red spider lily (L. radiata) produces 4-6 orange-red flowers on long stamens that curl upward, offering a spider-like floral appearance; grows best in partial shade and not in direct sunlight.

*L. squamigera* in a Johnson City TN Garden

Pink Surprise Lily (L. squamigera) blooms mid- to late-summer; leaves are broader and emerge in late winter and are gone by the time flowers emerge in summer.

Electric Blue Spider Lily (L. sprengeri)is a broadleaf deciduous perennial bulb / corm / tuber with. In fall and summer blue and pink flowers emerge. Grows well with sun and regular water. Prefers to be dry when dormant. Does well in average, rich and well-drained soil.

Where To Buy: Plant Delights Nursery in Raleigh, NC maintains one of the largest collections of spider lilies in the world. Brent and Becky’s Bulbs in Gloucester, VA list them in their spring catalog; bulbs are dug and shipped in May and should be planted as soon as they’re delivered. Newly purchased spring bulbs may not bloom the first season.

Summer – Fall Care Of Oakleaf Hydrangeas

Posted by Hugh on August 25th, 2024

‘Snowflake’ Oakleaf hydrangea in mid-August

Oakleaf hydrangea is an upright, multi-stemmed, deciduous shrub that is native in the Southeastern U.S. (USDA hardiness zones 5-9). Oakleaf hydrangea should be planted in a sheltered location and winter protection (e.g., mulch, burlap wrap) in northerly areas USDA Zone 5, particularly when not fully established. Oakleaf grows in moist, fertile, well-drained soil in sun to part shade. Shrub appreciates a 3–4-inch layer of organic mulch to conserve soil moisture and lessen weed pressure.

Fall foliage color is attractive—its leathery leaves turn purple, orange-bronze, or red. The peeling, exfoliating branches also provide winter color and texture. Shrub may lose significant numbers of flower buds or die to the ground in harsh winters (temperatures below -10°F), thus lessening or totally destroying all blooms the coming year. Attractive peeling cinnamon-color bark adds winter interest after the foliage has dropped.

Shrubs bloom occurs on old wood. Prune, if needed, immediately after flowering in June – July. Usually, little pruning is required other than to limit the shape (height/width) of oakleafs. Flower buds are formed in late summer into early autumn. Winter is NOT the time to prune oakleafs except to clean off dead or damaged stems.

Favorite varieties include ‘Ruby Slippers’, ‘Munchkin’, ‘Gatsby Girl’, and ‘Snowflake’. For a small postage stamp garden and in containers, plant Gatsby Gal^® or ‘Sike’s Dwarf’, both dwarf @3-4 ft. tall (and wide) cultivars. Leaves and flower panicles are smaller, tough reliable growers that require very little annual pruning.

Prune to remove old (spent) flower clusters, particularly those that are no longer attractive. Clip off attractive floral trusses to add to decorative arrangements. The old, dried cones are included in the winter holiday wreaths and swags.

Oakleaf hydrangeas have no serious insect or disease issues. Some susceptibility to leaf blight and powdery mildew. Aphids and spider mites are occasional pests. Like all hydrangeas, oakleafs are toxic to humans, dogs, cats, and horses. Unfortunately, they’re only slightly deer resistant.