Thermonasty – What Is It?

Rhododendron catawbiense – partial thermonasty following a series of cold TN nights in winter 2010

How cold did it get overnight? Perhaps you should check out your rhododendrons outside. The leaves of some rhododendron species (Rhododendron spp.) and Redneck Rhody (Daphniphyllum macropodum) droop down and/or curl up during really cold nights. Plant scientists believe that this reaction may be a plant’s way of reducing water loss through stomata cells on the undersides of leaves. This phenomenon is called “thermonasty” or “thermotropism”.

Rosebay rhododendron (R. maximum) also respond to thermonasty and Catawba rhododendron demonstrate a partial response. (USDA hardiness zones 6b-9). Most rhododendron species do not display this trait.

Scientists do not fully understand this plant tropism. It is thought to have something to do with leaf cell hydration. Thermonasty may also protect leaves during periods of high irradiance by sunlight. It may protect certain plants from cold temperature injury during daily thawing and re-freezing.

Thermonasty on R. maximum

Essentially, the leaves are a type of natural thermometer. When temps dip below 20°F, leaf margins curl inward leaves roll up and droop. During periods of exposure to extreme cold, reducing surface area helps to protect the leaves. On most days, leaves unfurl to their full natural position the next morning if temps rise above 32 °F (0°C).

Tropisms are useful adaptations with several important benefits. Leaves that are particularly susceptible to damage from desiccating winter winds—tightly curled leaves — ensure surface area is reduced, thereby mitigating this threat. Broad leaf positioning to maximize sunlight collection during dark winter days may be a liability when it comes to snow loads. Narrow, drooping, needle-like leaves shed snow that may otherwise accumulate and break branches.

Thermonasty response on Daphniphyllum

Caveat– gardeners may need to irrigate evergreen shrubs every 2-3 weeks if natural rainfall and snowfall levels are more than 60% below traditional seasonal amounts.

Russian arborvitae (Microbiota)

Russian arborvitae (Microbiota decussata) – spring/summer appearance

Russian arborvitae, aka Siberian cypress (Microbiota decussata), is a conifer ground cover that originates from frigid Siberia; it is exceptionally cold hardy to -40° F (USDA hardiness zones 2-7). Microbiota prospers in the cooler parts of the Mid-South (Kentucky, East Tennessee, Virginia, and Western North Carolina). Growth rate is slow to medium.

This amazing groundcover shows off its beautiful feathery green needle foliage from spring thru early fall. In fall it changes to coppery bronze in fall. It is utilized as a ground cover for banks and slopes. Microbiota takes a purple to bronze needle cast in late October and a brownish cast in winter. Spring warm-up restores its green needle color. It is more shade tolerant than and is an interesting alternative to ground cover junipers in northerly zones.

It forms a shrubby ground cover to 8-18 inches tall and may spread 10-12 feet wide. Feathery, soft-textured, scale-like (infrequently awl-shaped) foliage is arranged in flat, fan-like sprays reminiscent of arborvitae (Thuja). In appearance, it resembles the growth habit some of the horizontal junipers. Fruits are tiny, spherical, berry-like cones (to 0.25” diameter) with woody scales.

A well-drained soil is key to avoiding root rot, or plant in a dry location with a couple of hours of morning sun or light shade all day long. While exceptionally cold hardy, microbiota does not tolerate summer heat, drought, and high humidity. Alternatively, microbiota prefers good soil moisture drainage and cool temperatures, and tolerates windy exposed sites once fully established after two years. Deer and most disease and insect pests do not trouble it. 

Celtic Pride® is the leading cultivar

Celtic Pride® Siberian cypress is the leading microbiota cultivar selected for its uniform growth and resistance to tip dieback that plagues conventional varieties. Celtic Pride transforms areas into a lush evergreen carpet. It is intolerant to poorly drained soils, and hot and humid summers. Root rot may develop in excessively wet areas.

Microbiota is utilized as a specimen ground cover for banks and slopes, a ground cover for rock gardens, shrub borders, a costly lawn grass alternative around building and home foundations, and a shade alternative to ground cover junipers.

Although not commonly sold at local garden centers, microbiota may be purchase from online specialty nurseries in the U.S. and Canada.

Winter-blooming Snowdrops

Window box planting containing snowdrops at Brandywine Cottage outside Philadelphia, PA

Snowdrop (Galanthus spp.) are grown in both cold and moderate winters. In the U.S. snowdrops thrive where winters are cool (USDA hardiness zones 3-8). There are about 19 species of Galanthus – in the amaryllis family (Amaryllidaceae). They’re native to the cool woodland and mountainous regions of southern Europe and Asia Minor. They tend to struggle in warm climes in the U.S. like south Texas and southern California.

Snowdrops are among the first spring flowers to bloom, often around mid-February into early March. Purchase bulbs in fall and plant immediately after you receive them. Do not buy the bulbs too far ahead of time as they may dry out and lose viability. Space bulbs 3 – 4 inches apart. These tiny plants require very little maintenance. Snowdrops grow in a variety of garden spots.

Plant snowdrop bulbs 2-3 inches deep in soil that is prepared and ready for planting. Set bulbs with the thin end (tip) facing up. Feed with any commercially labelled bulb fertilizer to get the snowdrops off to good start. Each year in late fall, spreading 1-2 inches of well-refined organic mulch or compost should provide nutritional support to the snowdrop bed.

Snowdrop planting

Snowdrops are a collector’s dream. Try some of these favorites:

  • G. elwesii – “giant snowdrop” and grows to be twice as tall as G. nivalis.
  • G. nivalis ‘Flore Pleno’ produces double flowers.
  • G. nivalis ‘Sam Arnott’ – large flowered, vigorous and fragrant.
  • G. nivalis ‘Viridi-Apice‘ has prominent green blotch on its petals.
  • G. ‘White Dream’ has a white stripe on leaves.
  • G. woronowii – “green snowdrop” – broad green leaves and little green mark on inner floral tepals.

Numerous other cultivars are listed. One authority lists over 500 cultivars – most primarily available in Europe. Snowdrops can be mixed with other early blooming bulbous beauties such as Glory-of-the-snow (Chionodoxa), Winter aconite (Eranthis hyemalis), and Crocus (Crocus spp.).

Snowdrops prefer full sun (at least 6 or more hours of direct sunlight daily). Grow snowdrops in a loose, well-drained soil with lots of humus added. They don’t thrive in heavy clay soil. Once snowdrops have finished blooming, allow the foliage to yellow naturally and wither away.

Snowdrops come up every year, and multiply and spread over time; in fact, they are easy to naturalize. Every few years lift and divide the bulbs when you wish to propagate snowdrops.

Snowdrops are disease, insect and deer resistant, and critter-proof. They are toxic to animals and humans; keep pets and children away.

Snowdrop collectors, called “galanthophiles”, attend winter snowdrop meetings to buy new plant variants and other minor bulbs. Snowdrops and many minor bulbs are hard to find at garden shops. Brent and Becky’s Bulbs, an online

Snowdrop collectors, called “galanthophiles”, attend winter snowdrop meetings to buy new snowdrop variants and other minor bulbs. Snowdrops and other minor bulbs are hard to find at garden shops. Brent and Becky’s Bulbs, an online bulb emporium in Gloucester VA, is a personal favorite.

Summer Snowflakes (Leucojum)

Leucojum aestivium ‘Gravetye Giant’

Summer snowflakes originate from Europe and northern Africa and are carefree spring-blooming bulbs. They belong to the Amaryllis (Amaryllidaceae) botanical family and are critter proof. (USDA hardiness zones 4-8). Flowers and foliage are similar to snowdrops, but snowflakes grow twice as tall and bloom about 2-3 months later, usually just after most daffodils. Pure white, nodding, bell-shaped flowers are decorated with lime green spots. Blooms dangle in clusters from arching stems. Bulbs are reliably perennial and bloom reliably every spring for years to come.

Don’t be mistaken by its common name “Summer Snowflake”. They flower in mid-spring (April into early May) and bloom over 2-3 weeks. Summer Snowflakes (Leucojum) look a lot like snowdrops (Galanthus) which grow a lot smaller and bloom in mid to late winter. Whereas the three outer petals of Galanthus are larger than the three inner petals, all six floral petals in the Leucojum genus are the same length.

A flowering stem of summer snowflake is likely to bear more flowers—up to 6 or 7 per plant. Fewer than 2-3 flowers appear on a flowering stem, is an indication that plants are not receiving adequate sunlight. Primary snowflake species are:

  • L. vernum, a plant of about the same size as the giant snowdrop (1 foot tall), is called the “spring snowflake.” It blooms in mid-spring.
  • L. aestivum is similar in size to L. vernum, but blooms slightly later in mid-spring.
Leucojum naturalized with Green and Gold (Chrysogonum virginianum)

Plant the bulbs 5 – 6 inches deep and 5 – 6 inches apart on center. Design for a natural look by planting snowflakes along a woodland path or a rock garden in groups of 10 or more bulbs. Give them at least half-day sun and they flower at their best under limbed up small trees or large shrubs. Let the foliage remain to rebuild the bulbs before summer dormancy sets in.

Snowflakes adapt well to most soil types and bulbs are soil pH insensitive. Bulbs require moisture during the early growth season and are moderately drought tolerant during their summer dormancy period.

Container Design – List Of Spillers

Dichondra argentea ‘Silver Falls’

Spiller plants are species that trail over the edge of the pot with a cascading growth habit. Combined with erect-growing “thriller” plants as the focal point in container gardens, spillers bring texture, color, and visual interest to the rest of the pot. Trailing plants provide a “full look”, draping over edges of hanging baskets and containers.

‘Snow Princess’ alyssum (Lobularia)

Below is a list of 24 trailing plants (spillers) that compliment any container garden. This is not a complete plant listing.

Calibrachoa basket
  1. Dichondra (Dichondra spp.) has blue-green or silver foliage that spills over the edge of containers. Grow in full sun and moist well-drained soil. Highly recommend D. argentea ‘Silver Falls’ (Z 10-11).
  2. Licorice plant (Helichrysum petiolare) is grown for its small, a soft blue-gray leaves. Also, variegated leaf varieties are available. Grow in full sun and moist well-drained soil. (Z 9-11).
  3. Joseph’s Coat (Alternanthera dentata) is colorful foliage plant group that spills with charm. Grow in full sun and moist well-drained soil (Z 10-11). 
  4. Bidens (Bidens ferulifolia) are covered with small, daisy-like flowers available in yellow, pinks, white, and orange that drape over the sides of a window box or hanging basket. Best in full sun and is drought tolerant. (Z 8-11).
  5. Sweet Potato Vine (Ipomea batatas) thrive in large containers. Choose from heart-shaped or oakleaf-like foliage, available in many colors from green, chartreuse, to almost black; dwarf-leaf varieties are also available; grow in full sun and moist well-drained soil. (Z 9-11).
  6. Tradescantia ‘Zebrina’ has a 9-inch trailing plant with multi-colored lance-shaped leaves. Rose-like flowers appear in spring. (Z 8-12)
  7. Poppy Mallow / Wine Cups (Callirhoe involucrata) is a stunning spiller (trailing) plant that produces vibrant cup-shaped flowers in shades of pink, purple, or white. (Z 4-8)
  8. Batface cuphea (Cuphea llavea) grows 20-30 inches tall and wide, covered with 1-inch tubular flowers with a purple calyx and a pair of red ear-like petals that resemble the face of a bat; attract hummingbirds and butterflies; best in full to partial sun and moist well drained soil. (Z 9-12).
  9. Mexican heather (Cuphea hyssopifolia) produces abundant purple flowers on a versatile, tidy, compact annual with finely textured, glossy, bright green foliage. In bloom continuously, well into fall. (Z 8-11).
  10. Firecracker plant (Cuphea x llavea) grows 18-28-inch-wide green stems with abundant yellow orange flowers all season long; pollinator and hummingbird fav. (Z 8-11).
  11. Tradescantia ‘Zebrina’ is a 9-inch trailing plant with multi-colored lance-shaped leaves and rose-like flowers in spring. (Z 8-12).
  12. Poppy Mallow or Wine Cups (Callirhoe involucrata) is a stunning spiller (trailing) plant that produces vibrant cup-shaped flowers in shades of pink, purple, or white. (Z 4-8).
  13. Nasturtium (Tropaeolum) form a mounding tumble of lily pad–like leaves and bright, cheerful flowers. Grow in partial sun, moist well-drained soil, and a cool site is preferred. (Z 9-11).
  14. Plectranthus (Plectranthus argentatus) is beloved for its silver-gray foliage. Varieties ‘Mona Lavender’ and ‘Silver Shield’ bear attractive, fuzzy, gray-green foliage with spiky sprays of lavender blooms from late summer to fall. (Z 8-11).
  15. Sweet Alyssum (Lobularia maritima) is a sweetly fragrant blooming annual that drape over the edges of containers, in the garden, or to fill nooks and crannies on walkways and walls. Favorite variety- Snow Princess™ (Z 7-10).
  16. Fan Flower (Scaevola) is an evergreen tropical plant with deep green leaves and odd little flowers that have petals only halfway around their center disks, giving them the look of a fan. Grow in full to partial sun and well-drained soil. (Z 10-11).
  17. Black-Eyed Susan Vine (Thunbergia alata) has tiny five-petal flowers in yellow, peach, or white. Grow in full to partial sun and moist well-drained soil. (Z 10-11). 
  18. Verbena (Verbena peruviana) is grown as an flowering annual in full sun and moist well-drained soil. They are also very heat tolerant. (Z 8-11). 
  19. Madagascar Periwinkle (Catharanthus roseus), aka annual vinca, is often used as a flowering ground cover that trails over the sides of containers. Grow in full to partial sun and well-drained soil. Recommend ‘Pacifica’, ‘Cora’, ‘Soiree’. (Z 10-11).
  20. Wave petunias (Petunia x hybrida) grows in full sun and moist well-drained, acidic soil; pinching and deadhead flowers in mid-summer for renewed flowering. (Z 10-11).
  21. Million Bells®, Super Bells® (Calibrachoa x) is a smaller flower cousin to petunias with same growing needs. (Z 10-11).
  22. Narrowleaf Zinnia (Zinnia angustifolia) are small-flowered spreading zinnias with much improved powdery mildew resistance. Profusion® and Zahara® series are highly rated. (Z 8-10).
  23. Creeping Jenny (Lysimachia nummularia) has a viny trailing plant habit along with vibrant chartreuse leaves that rapidly in containers; considered invasive plant in garden areas. Grow in full sun and moist well-drained soil. (Z 4-9).
  24. Creeping Zinnia (Sanvitalia procumbens) forms a lush green mat covered in yellow flowers in summer that drape over sides of containers. Grow in full to part sun and moist well-drained soil. Z 2-11).
Batface cuphea (C. llavea)

Native Sedum (Three-leaved Stonecrop)

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

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.

Seven-son flower (October bloom)

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.

Exfoliating, tan-colored bark
  • 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

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

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)

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).

Cyclamen hederifolium

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).

Nerine (Guernsey Lily)

Toad Lilies Shine In The Autumn Garden

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.

Tricyrtis hirta ‘Miyazakii’

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.

Nice bed of toadlilies

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 stemsMany 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.