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

Update On Perennial Ironweeds

Posted by Hugh on October 2nd, 2026

*Vernonia* in bloom at University of Tennessee Gardens, Knoxville, TN

U.S. native ironweeds (Vernonia spp.) develop a broad visual swath from the mid-Atlantic to the Midwest and from Minnesota south to Texas. Vernonia spp. is in the aster or daisy family (Asteraceae). Their abundant purple-hued flowers brighten the autumn landscape from late summer into autumn. Ironweeds serve as an important food source for pollinators. Scores of bees, butterflies, and numerous other insects feverishly work the flowers.

In general, wild ironweeds grow too tall in most gardens. Recent breeding efforts by Dr. Jim Ault (now retired) at Chicago Botanical Garden has resulted in a number of improved hybrid selections. Late-season bloomers such as sunflowers (Helianthus spp.), goldenrods (Solidago spp.), and big bluestems (Andropogon gerardii) are stellar garden companions.

Mt. Cuba Center near Wilmington DE conducted a four-year trial that evaluated 45 different Vernonia species and cultivars in full sun from 2020-2023. Their focus was on their ornamental and ecological value of ironweeds. Fungal diseases including rust and powdery mildew were common in this trial, although some selections remained virtually free of infection. MT. Cuba Center is located near Wilmington, Delaware and is within USDA hardiness zone 7a.

The largest ironweed in the MT. Cuba trial was V. gigantea ssp. gigantea ‘Jonesboro Giant’ which topped 12 feet in height; flowers 7-10 days earlier than other varieties; dark burgundy rigid stems stand boldly upright into October; heavy bloomer, massive 12″ wide inflorescences of ¾-inch-wide purple flowers.

The soft, needle-shaped leaves of V. lettermannii ‘Iron Butterfly’ is a popular at many garden centers in late summer; grows 2.5 – 3 ft. tall in a mounding habit; purple flowers are highly floriferous; less prone to splaying in the center in heavy rain. Powdery mildew and rust were rarely an issue.

‘Southern Cross’ (photo credit: Brent Horvath)

‘Southern Cross’ – dark green, willow-like foliage is slightly wider than many ironweeds along with a bronze cast to the terminal leaves and purplish stems; bright purple 1-inch-wide flowers from mid-August to late September; stems sturdy erect with bushy habit (40″ tall x 33″ wide); foliage mildew resistant and rust susceptible. (Brent Horvath introduction at Intrinsic Nursery).

‘Summer’s Surrender’ grows 4 ft. tall and 6-6.5 ft. wide with a densely broad habit resembling ‘Southern Cross’; large clusters of dark purple flowers; foliage resistant to powdery mildew and rust. Bred by Dr. Jim Ault and selected the 2027 Perennial Plant of the Year.

Vernonia ‘Summer Surrender’ (2027 PPOY) – Dr. Jim Ault introduction

‘Summer’s Swan Song’ (a hybrid cross of V. lettermannii and V. arkansana) has the bushy habit of V. lettermannii and larger plant size of V. arkansana; olive-green linear foliage. (Jim Ault introduction).

Ironweeds put on an impressive show in native and naturalistic landscapes, meadows, and formal gardens. Powdery mildew and rust can infect foliage in late summer or fall—some species are more susceptible than others. Disease levels can be severe in some years on native populations. The bitter-tasting leaves keep most grazing mammals including deer away.

Heleniums Are Nothing To Sneeze At

Posted by Hugh on September 25th, 2026

Helenium Helenium autumnalis), aka sneezeweed, is a cheerful, daisy-like perennial wildflower that lights up moist meadows and stream banks across nearly all of North America with masses of golden-yellow flowers from late summer through fall (USDA hardiness zones 3–8).

It has an unfortunate common name – “Sneezeweed”— which refers to a historical use of dried flower heads as snuff to induce sneezing. Fortunately, at least for humans, helenium has no allergy-causing properties. Helenium is a member of the aster (Asteraceae) family is a beautiful native wildflower species for wet-site gardens and prairie plantings. Quizzically, its scientific genus Helenium supposedly is said to honor Helen of Troy??

Heleniums grow 2 to 5 feet tall with an upright, branching habit and produces abundant clusters of distinctive flowers. Floral heads measure 1-2″ across, with 3-lobed ray petals that curve downward. The brightly colored flowers, with brown-gold button centers or “cones”, bloom from August – October.

Leaves are alternate, lance-shaped, 2 to 6 inches long, with toothed margins and a distinctive feature: the leaf bases extend down the stem as “wings,” giving the stems a winged appearance. Dark green foliage is slightly rough-textured. Lower leaves may be larger and more broadly lance-shaped than upper ones.

This U.S. native is found from coast to coast, growing naturally in wet meadows, stream banks, moist prairies, ditches, pond margins, floodplains. Helenium thrives in full sun — at least 6 – 8 hours of direct sunlight daily. In shade, plants become leggy, floppy, and produce far fewer flowers. It thrives in moist to wet soils and tolerates heavy clay, loam, and even slightly sandy soils as long as moisture is consistent. The species struggles in dry, well-drained sites.

Plant in spring or fall, spacing plants 18 to 24 inches apart. Sow seeds in fall for natural stratification, or cold-stratify for 30 days and sow in spring. Seeds require light for germination, so tamp them lightly into the soil without covering them. Nursery transplants establish quickly and typically bloom the first year.

Pinch or cut back stems by half in early summer (June) around “Chelsea chop” time to promote bushier growth that won’t grow tall and floppy. Deadhead spent flowers to extend blooming. Cut to the ground in late fall or early spring. Divide clumps every 3–4 years in spring to maintain vigor. It grows alongside species such as Joe-Pye weed, boneset, blue lobelia, cardinal flower, swamp milkweed, and many others.

Helenium grows in moist, low-lying meadows or at the edges of soggy woodsy areas. Over the years plant breeders have expanded helenium varieties to include several shades of gold, orange, red, and bicolors. Helenium flowers attract butterflies in late summer and fall. Numerous cultivars are available in festive, warm colors like ‘Mardi Gras,’ ‘Salsa’, ‘El Dorado’, ‘Butter Pat’, and ‘Siesta’.

Helenium is valued as a late-season nectar and pollen source for native pollinators. Seeds are sort after by goldfinches, sparrows, and many foraging birds. Winter dried stems offer shelter and forage for overwintering insects and birds to feed upon. Vegetation can be toxic to cattle, horses, and sheep if consumed in large quantities. Helenium is also highly deer resistant.

Tis The Season For Hardy Cyclamens

Posted by Hugh on September 18th, 2026

Two species of Hardy Cyclamen fill a void in autumn and late winter garden. Your choices include fall-blooming Ivy-leaf Cyclamen (Cyclamen hederifolium) and spring flowering Hardy Cyclamen (C. coum). Leaves of several varieties are splashed with silvery designs. Hardy Cyclamen fill a void in autumn and late winter in a shady woodland garden, I decided to try a different species. Leaves of several varieties are splashed with silvery designs.

These are not the cyclamens you know as florist or house plants (C. persicum). Hardy cyclamen grow to 4-6-inches in height and produce white to varied pink floral shades that are 1-2-inches long with swept-back petals from September to October (USDA hardiness zones 5-9). While the flowers are the main attribute, decorative foliage is up next. Ivy-shaped leaves have dark green centers bordered with lighter green and silver patterns. Plants produce leaves after the flowers. The foliage remains through winter before going dormant in spring.

Punishing heat and drought does not trouble dormant cyclamens in summer. Return of rain and cool temps in late summer into fall awakens these shallow planted tubers. Single white or pink flowers on slender stems push up through the leaves. More and more flowers soon followed.

Hardy cyclamen grow best in moist, well-drained soils that are rich in organic matter. They prefer dappled to moderate shade, particularly in the afternoon. Hardy cyclamens are generally long-lived and increase in numbers over the years. At first, newly-planted cyclamen generate a few flowers. Over the years, well-established clumps produce lots more.

Plant them in bunches for best show as in dry shade groupings, and in containers, and rock gardens. The colorful tiny cyclamen flowers and patterned leaves have their own charm. Success after a few years is measured when loads of seedlings colonize in a clump.

Mottled foliage in early spring of C. hederifolium

Cyclamen hederifolium grow well in containers in the garden. Cyclamen tubers are planted shallow – two inches deep and six inches apart in partial shade in well-drained, humus-rich fertile soil. Plants are tolerant of acidic, clay, loamy, and sandy soil. Good soil drainage is absolutely essential. Tubers will rot in wet, heavy soil. Moderate shade and long summer dry periods is key to the fact that they need no water in summer. By the time they break dormancy in fall, we’ve entered our rainy season that lasts through spring.

Cyclamens are deer resistant. Be on the lookout for field mice (voles) and squirrels that may be attracted to them. Important Note: plants and tubers may be toxic to cats and dogs.

*Cyclamen coum* f. *pallidum* ‘Maurice Dryden’

Availability: check online at Brent & Becky’s Bulbs in Glouchester, VA. Pine Knot Farms in VA, Edgewood Gardens, Exton PA, and Plant Delights Nursery in Raleigh, NC. Some are online sales only.

Winter Berries For Birds

Posted by Hugh on September 12th, 2026

Spring-summer flowers lead to an attractive & bountiful harvest of berries in your landscape. In the cool autumn and snowy frigid winter months, our feathered wildlife feast on colorful berries that range from purple, red, pink, white, or blue. Listed here are 12 berry-licious plants.

1. Winterberry (Ilex verticillata) is a deciduous holly native to eastern North America. Once its leaves drop in fall, the bright red berries puts-on a spectacular winter show. Standout fruit-bearing female choices are ‘Winter Red’, ‘Sparkleberry’, ‘Berry Heavy’, and ‘Berry Poppins’. Also add ‘Winter Gold’ for its yellow berries. Don’t forget to plant a matching male pollinator like ‘Southern Gentleman’ or ‘Jim Dandy’. (Zones 3-9).

2. American Holly (Ilex opaca) is a U.S. native, 15-30 feet upright, pyramidal, evergreen tree; eventually may reach 50 feet tall with spiny, thick, leathery, green leaves and bright red berries. Its berry-laden boughs define the Christmas holidays. Bright red or orange, 1/4 – 1/2″ diameter fruits ripen in fall on pollinated female trees that persist through winter. (Zones 5-9). Other Ilex spp are also decorative.

3. Flowering Dogwood (Cornus florida) is a small 15–30 feet tall and wide native tree that blooms in early spring (April) with showy, white, 3-4” wide, 4-petaled flowers (bracts). Bright red drupe fruits are relished by birds and other wildlife when they ripen in early fall; berries often persist into late December. (Zones 5-9).

4. Red-twig Dogwood (Cornus sericea) produces blue fruit in summer and bare red stems in winter give this shrubby dogwood. Tiny, fragrant, white flowers appear in flat-topped 2.5” wide cyme floral clusters in late spring. Flowers give way to clusters of whitish (sometimes with a bluish tinge) fruits. Every 2-3 years cutback shrub hard to a foot or less in late winter to rejuvenate bright red winter stems. (Zones 3-7).

5. Crabapple (Malus spp.) is a popular spring flowering small to medium sized ornate tree. Depending on the choice of cultivar, loads of colorful fruits (reds, yellow, orange, green) ripen in early fall; birds prefer crabapple varieties bearing fruits less than 2 inches in diameter. Choose crabapple cultivars for their foliar disease resistance. (Zones 4-7).

6. ‘Winter King’ Hawthorn (Crataegus viridis ‘Winter King’) is a popular disease-resistant cultivar that blooms profusely, bears heavy crops of fruits, silvery-barked stems, and foliage with attractive purple and scarlet fall color. (Zones 4-7). Several other hawthorn species may also be listed here.

7. American Beautyberry (Callicarpa americana) produces tiny pinkish blooms in mid-summer followed by traffic-stopping clusters of luscious small purple berries. While this native form is preferred, other species are also stunning in autumn. (Zones 5-8).

*Symphoric*arpos orbiculatus ‘Proud Berry (photo from Proven Winners)

8. Coralberry (Symphoricarpos orbiculatus) is an under-utilized native shrub. Small, yellowish summer flowers turn into purplish-red fruit clustered along arching stems beginning in October. Highly recommended is cultivar Proud Berry®, 3- to 4-foot plant that is loaded with plump, dark pink berries that intensify with cold weather. (Zones 2-7).

9. Snowberry (Symphoricarpos albus) is native shrub with arching branches that bear beautiful clusters of white berries that last well into winter. It bears small white and pink flowers in summer that attract butterflies and hummingbirds; it is a host plant for the Sphinx Moth. (Zones 3-7).

10. Chokeberry (Aronia melanocarpa) produces black autumn berries and has attractive purple/red fall color. They excel in wet soggy ground areas, sucker, and form mass colonies. White spring flowers are followed by glossy summer leaves and brilliant red fall foliage and loads of fruits. (Zones 3-8).

11. Serviceberry (Amelanchier x grandiflora) is a graceful, multi-stemmed large shrub or small 12-15 feet tall tree native to eastern North America; closely related to A. arborea. Spring leaves emerge with a distinctive attractive bronze to purplish-red color. White flower clusters open in early spring as the last snows of winter are leaving your region. Edible berries, called Juneberries, ripen to deep purple-black in late spring and are often used in jams, jellies and pies. Leading varieties: ‘Autumn Brilliance’ and ‘Princess Diana’. (Zones 3-9).

12. Viburnums (Viburnum spp.) represent a broad group of spring flowering shrubs that produce loads of colorful red, pink, black, and blue berries in late summer and fall. Some of the best native viburnums for feeding birds: smooth witherod (V. nudum), possumhaw, cranberrybush viburnum (V. trilobum), arrowwood viburnum (V. dentatum), nannyberry (V. lentago), and blackhaw (V. prunifolium). (Zones 4-9).

Care tips: Prune fruit-bearing shrubs at the proper time, which results in heavy flowering and seasonal fruit loads to follow. Keep landscape plants neat by removing dead branches and basal suckering. Cutting back may also spur on a new growth flush and abundant berries to follow.

‘Winter Gold’ deciduous holly -fruit set in mid-October

Add Chinese Pistache To Your Landscape

Posted by Hugh on September 3rd, 2026

Chinese pistache tree (Pistachia chinensis) is a 25–40-foot small to medium landscape tree in the Botanical family known as Anacardiaceae. Branching habit is slightly upright that creates a narrow tree profile that is ideal for a small patio or a curb-side street tree. The bark of a young tree is silvery gray with a more rugged blocky pattern as an adult. (USDA hardiness zones 6-9).

This lovely small tree is indigenous to China, Taiwan and the Philippines (USDA hardiness zones 6-9). Tree grows 1-2 feet a year It is related to the edible pistache nut tree (Pistachia vera) but without producing any messy nuts. A variety of birds and yard wildlife consume the nutlets, which are not very tasty to humans.

Foliage consists of dark green, alternatively arranged pinnate compound leaves to 10 inches long, each leaf typically having 10-12 lanceolate leaflets to 4 inches long. Tree displays a fine leaf texture, and the small leaflets are easy to rake up in the fall and incorporate as a mulch in a flower or veggie bed. Foliage is aromatic when bruised. In some years autumnal leaf color can be an eye-catching crimson red, bright orange, and occasionally yellow.

Chinese pistache is dioecious, e.g. a single tree is either male or female. Pistache blooms in April but go relatively unnoticed compared to more showier spring blooming shrubs and trees. Female flower clusters are nearly twice as wide as males. The non-edible ¼ inch diameter drupe fruits turn red in summer before ripening to bluish-purple in late fall. Berries are a food source for birds. Gray-brown bark on older trees peels to reveal salmon colored inner bark.

This tree grows in moist, compost-rich, well-drained soils and in full sun. It can also handle full-day part shade. This a low-maintenance tree is tolerant of drought, heat, and heavy clay soils. In most landscape situations Chinese pistache is free from serious pests and disease. Verticillium wilt may become a serious disease in poorly drained soils. Annual pruning in early years is essential to develop a desired symmetrical tree with good form.

A small specimen is suitable for patios and gardens. If you are concerned about berries dropping on walkways, select a fruitless male clone, P. chinensis ‘Keith Davey,’ a 35-foot-tall tree with a crown diameter of 30 feet. Female variety ‘Sarah’s Radiance’ produces lovely red fruits and nutlets in the fall. ‘Pearl Street’ is a very fast-growing seedless variety with an upright form.

Chinese pistache is rarely sold at local garden centers but can be found at e-commerce on-line nurseries.

Late Blooming Swamp Azalea

Posted by Hugh on August 28th, 2026

Native to the southern and eastern U.S., swamp azalea (Rhododendron viscosum) is a deciduous shrub in the Ericaceae (blueberry) family. This shrub generally grows 3 – 8 feet tall and nearly as wide. It is a spreading shrub that spreads slowly via underground stolons and is most at home in a moist humus-rich soil that is moderately drained. Swamp azalea prefers part shade and will tolerate morning sun. Direct afternoon sun will likely scorch leaves.

This shrub has very fragrant, sticky, white (occasionally pale yellow) tubular flowers. It is indigenous to swamps, bogs, stream margins, and wet lowlands from southwestern Maine to northeastern Ohio south to Florida and Alabama. Flowers bloom from May to July which attract hummingbirds, bees, and other pollinators.

Their sweet, clove-like scented, sticky, white fluted flowers are wonderful from May to July and attract hummingbirds, native bees, and other pollinators.

In naturalized landscapes pay careful attention to its growing requirements. Its fall foliage colors are variable — yellow, burning orange, red, and burgundy. The shrub spreads by stolons to form dense, colony-forming thickets that provide excellent cover and nesting habitat for wildlife. Include swamp azalea as a specimen in a native garden or an understory shrub in woodland planting.

Several native azaleas, including swamp azaleas, are susceptible to Phytophthora root rot—this leads to leaf loss, reduced vigor, branch dieback, and wilting.

*R. viscosum* ‘Lemon Drop’ – fragrant pale-yellow flowers in early summer & glossy green leaves turn dark pink-red and yellow in fall (Weston Nurseries, Hopkinton, MA)

Avoid planting near roots of a black walnut or butternut tree which produce toxic juglones that typically damage or kill rhododendrons/azaleas growing within or close to the tree drip line. It is best sited in a location away from strong winter winds. This shrub has a shallow, fibrous root system (do not cultivate around the shrub); instead, mulch with wood chips, bark or pine needles) for moisture retention, cooling soil temperatures, and winter protection.

Wonderful native azaleas are available from e-commerce nurseries. Best time to shop for them is in late winter and early spring. In Tennessee, East Fork Nursery (Sevierville), Beaver Creek Nursery (Bybee), and Gro-Wild Nursery (Fairview) are excellent sources. Add Plant Delights Nursery in Raleigh, NC, Carolina Native Nursery in Bernsville, NC, Weston Nurseries in Hopkinton, MA, and Broken Arrow Nursery in Hamden, CT.

Buttonbush

Posted by Hugh on August 11th, 2026

Buttonbush (Cephalanthus occidentalis), aka honeybells, pond dogwood, and swampwood, is a highly prized native shrub. Yes, in small landscapes, buttonbush tend to grow big @ 6-12 feet tall and wide. Their fragrant white orbital blooms are uniquely out of this world. Botanical member of the Rubiaceae (USDA hardiness zones 5-9), flowers appear from spring to fall.

Buttonbush is a fast-growing hardy deciduous shrub. For best results plant buttonbush in moist humus-rich soils in full sun to partial shade. Nature has created this unusual out of this world white, spiky flowers with fragrant aroma. Buttonbush grows best in wetlands or near rivers and is often utilized for erosion prevention. The shrub requires full sun but may tolerate some shade.

Buttonbush needs consistently moist to wet, rich soils in standing water up to 3 feet. It is adaptable to various soil types, except for dry ones, and is tolerant of heat and soil compaction. Flowering is poor in the shade or in dry ground. It is multi-stemmed with a rounded to irregular crown and needs little pruning.

Seedling buttonbush is usually grown as a 6-12 feet tall and 8 feet wide shrub. Occasionally, you may see it trained into a 20 feet tall shrub. Small, fragrant, white, tubular flowers appear in June to September. Fruits turn reddish-brown in late summer and persist into winter. Buttonbush has exceptional wildlife benefits, attracts a variety of pollinators to gardens, along with waterfowl, songbirds and mammals. The foliage of buttonbush is toxic to humans. Browsing by deer is generally uncommon.

Buttonbush is available via on-line nurseries in spring and rarely sold at local garden centers. However, dwarf cultivars are entering the garden marketplace which should increase the shrub’s popularity.

Buttonbush growing at Morris Arboretum in Philadelphia PA

Buttonbush thrives in 6-8 hours of sun along with moist humus-rich soil. Plant buttonbush in soil that is neutral to slightly acidic pH of 6.8 to 7.2 and avoid alkaline soils. Feed with a slow-release fertilizer like Osmocote in spring.

New compact forms are great options for smaller gardens, rain gardens, and foundation beds where scale matters. ‘Sugar Shack’ buttonbush was selected as the 2023 North Carolina Wildflower of the Year and was awarded the Pennsylvania Horticulture Society Gold Medal Shrub in 2024.

Current Popular Varieties:

‘Bailoptics’ a small variety only reaching about 6 feet high and wide.
‘Bieberich’ – grows up to 12-15 feet high and wide; pale pink or pinkish-white blooms rather than the usual white flowers; bronze leaf color in fall.
Sugar Shack^®– dwarf dense foliage shrub that grows up to 5 feet high and wide; burgundy fall foliage and red fruit in winter.
‘Sugar Shack 2.0 – compact 3-4 feet tall and wide its spherical white blooms, resulting round seeds (nutlets); fabulous fall color of both nutlets and foliage.

Gold And Silver Chrysanthemums

Posted by Hugh on August 3rd, 2026

Gold and Silver chrysanthemum (Ajania pacifica) is a shrubby herbaceous flowering perennial in the aster family (Asteraceae). This groundcover is native to central and eastern Asia. It is a mound-forming, rhizomatous perennial that is grown for its attractive variegated foliage from spring thru autumn. This groundcover is used seen more in Southeast gardens. Its dense foliage mounds up to 18-24 inches tall that spreads over time via rhizomes to 36 inches around.

Gold and Silver chrysanthemum thrives in full sun but tolerates partial shade. Some afternoon shade is beneficial in hot summer beds. Plants may appreciate winter protection in where winter temps are colder (USDA hardiness zones 5-9). It grows well in all types of soil as long as drainage is good; it performs poorly in soggy ground. It appears to be soil pH insensitive and thrives in all types of soil. Feed with a slow-release fertilizer in spring. In mid-June, lightly shear back growth 1-2 inches to spur additional flower buds in fall.

This perennial ground cover reaches its full mature size in 2 -3 years and is easy to keep under management. Over several years it can span 3 feet wide. Pinch or shear back tall stems in June or July to maintain a dense, bushy growth. Irrigate during long dry spells but do not over-water. Propagation is easy via stem cuttings or by dividing the root ball in spring.

Scallop-edged, blue green 1.5 – 2-inch leaves are etched with ornate silver margins. Undersides are covered by a silvery down. A nice groundcover mum bears the clusters of tiny yellow buttoned flowers in late fall, perhaps the last chrysanthemum to bloom. Its long bloom period is from mid-October thru November, often with mid- 20’s temperatures that don’t faze it.

No significant disease or insect pests bother this mum. Wet damp soils in winter will lead to root and crown rot. Deer pay this mum relative much attention. This ground cover mum deserves to be planted more as a fall season extender.

One cultivar: ‘Pink Ice’ is another color choice with 3.5 to 4-inch-wide short pale pink petals and light-yellow centers.

Happy Summerific™ Hibiscus Week 2026

Posted by Hugh on July 27th, 2026

Hibiscus (‘Cookies and Cream’) – low compact grower (Walters Gardens (WG) photo)

Rose mallow (Hibiscus moscheutos) is a truly versatile perennial. Hardy from Minnesota to Florida (USDA hardiness zones 4-9), rose mallow bears some of the largest flowers compared to most other perennials. Blooms of some cultivars measure a huge 7-9 inches across. In addition, dwarf compact growing types are being developed that make perfect fits in containers.

Summerific® Hibiscus from Walters Gardens, Inc. produce varieties that bloom up and down the stems, not just at the top. Flowers last three times longer and produce 3 times the number of buds.

Hibiscus ‘Cherry Choco Latta’ – (WG Photo)

Four Growing Tips:

First – give clumps room to grow. Tall varieties grow 4-6 feet tall and wide and dwarf varieties are planted at least 3 feet apart. Do not crowd them next to other perennials for space.

Second – water, water and more water is key to successfully growing rose mallow. Plant on a site that is nearby a hose or sprinklers. Whether your soil consists of clay, sand or something in between, do not let the plant wilt and dry out. You’ll know it is not getting enough water if it becomes scraggly looking and drops its lower leaves and flower buds.

Third – plant them where the sun shines the most, if not, all day long. Rose mallow loves hot, humid, sunny weather, and foliage and flower colors look best in full sun. You’ll have more flowers too. If your garden spot is in partial shade (less than 4 hours of sun), expect fewer flowers; varieties with purple foliage will appear more greenish.

Fourth – Mark the garden spot where you planted them. Use a weather-proof 4-season marker. Why: rose mallows are late rising perennials. When other garden perennials are showing signs of life in early spring, rose mallows are still fast asleep. Shoots emerge often in early to mid-May, grow rapidly, and start blooming in July and August, depending on variety and garden zone.

In spring, before you see the new foliage appears, prune or lop off the old woody stems to the ground. New spring growth emerges from the stubble of last year’s plant.

In spring apply a balanced slow-release plant food such as Osmocote™ around the plant base to nourish it for several weeks. Water-soluble plant fertilizer such as Miracle-Gro® or Miracid® in early summer just as its flower buds are beginning to form to help the plant have energy to produce lots of flowers.

Final tip is to label the cultivar, save the label as new varieties appear at garden centers every year. Expect that your garden collection will grow. Disease and pest problems are minimal. Be watchful for hibiscus sawflies and Japanese beetles. Deer may nibble on new shoots, but once established, deer browsing becomes less of a concern.

Recent Releases In the Summerific® Hibiscus series:

‘Holy Grail’ – 8-9-inch-deep red flowers; bright green center calyces; compact 4.0 to 4.5 feet tall and 4.5 to 5.0 feet wide with near black foliage.

‘Cherry Choco Latta’ – 8–9-inch-wide white flowers with deep pink veining & large red eye; compact 3.5 x 3.5 feet tall and wide; dark olive-green foliage.

‘Cookies and Cream’ – 6-7-inch-wide pure white flowers (incl. eye); compact 2.5 -3.0 feet tall to 3.5 – 4.0 feet wide with matte black foliage.

‘Garnet Globes’ – 7-inch-wide dark garnet red flowers; compact 3 feet tall and wide with dark olive-green foliage.

‘Evening Rose’ – 8-inch-wide puckered magenta flowers with green calyces; near black foliage.

Dwarf Vitex Cultivars

Posted by Hugh on July 22nd, 2026

‘Shoal Creek’ vitex in container at Atlanta Botanical Garden

Chastetree (Vitex agnus-castus) is an 8–10-20-foot deciduous shrub or tree form. Branching habit is dense and vase-shaped (upright). Without question, ‘Shoal Creek’ is a very popular Vitex variety that measures around 20 feet tall and 15 feet wide (USDA hardiness zone 6 – 8). So… so many varieties that grow large and should not be planted in small gardens. Read further!

Vitex blooms off and on through much of the summer –June thru late August. Its 12-18 inch long blue-violet flower spikes and leaves emit a pleasant, sweet fragrance. From personal observations, cold hardiness of some varieties is better than others. The May-June palmately compound foliage has a pleasant dusty bluish cast and summer foliage color is grayish green. Pointed finger-like leaflets are dusty on the surface with pubescent hairs. Its disease resistant foliage and butterfly/bee magnetism rates chaste tree in a class on its own. Foliage is highly deer resistant.

‘Blue Diddley’ – early summer bloomer; blemish-free foliage

Vitex prefers full sun but will tolerate part sun (with lower flower count). Plant in loose, well-drained soil and keep adequately watered during the first year. Vitex adapts to problem soils and demonstrates exceptional drought tolerance.

Following is a list of dwarf Vitex shrub forms:

Blue Diddley^®– Blue summer flowers on a compact plant (3-6′ high and wide).
Blue Puffball™ – 3- 6′ shrub; 4-5″ blue flower spikes.
Delta’s Blues™ – 8-10′ tall and wide shrub with glossy green foliage and rich blue green foliage.
Featherman^® – sterile flowers, compact grower (3-5′ tall x 2-3′ wide), ideal for containers. (z 5b-9).
‘Galactic Pink’ – 6-8′ high and wide shrub; pink flowers from June to October; dark green foliage.
‘Pink Sensation’ – 10′ high x 15′ wide with pink flowers in early summer.
Rock Steady^®– 4-12′ height x 4-6′ wide; light purple blooms.
‘Salina’s Pink’ – 15′ high and wide with pink flowers emerge in summer and fall.