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

2023 Triple Crown Winner: ‘American Gold Rush’ Black-eyed Susan

Posted by Hugh on January 6th, 2023

For 2023, three leading organizations, All-America Selections, National Garden Bureau and Perennial Plant Association, have awarded a cultivar of black-eyed Susan their highest plant award in the U.S. For the U.S plant Industry this is the first time ever.

Currently, garden interest in rudbeckias is at an all-time high. All-America Selections judges evaluated ‘American Gold Rush’ for three years and noted how easy it was to grow and is an exceptional perennial as well. The variety was very attractive in the perennial garden with nice full bloom coverage late in the season.

‘American Gold Rush’ is a top garden performer. It is full of flowers by mid-summer and expect a long season of dazzling color right up to autumnal frosts. Its narrow 2-inch wide, hairy green foliage is resistant to Septoria leaf spot – a nasty fungal disease that causes unsightly black spotting and premature seasonal decline on some rudbeckia varieties. It’s a reliable hardy perennial and a stunning focal point in perennial borders and meadows as well as being brilliant when massed in public or corporate landscapes.

In the world of perennials rudbeckias are very easy for TN /VA gardeners to grow. Rudbeckias are native to much of North America. Rudbeckias are pollinator friendly and there are many new varieties to try.

American Gold Rush at Dawes Arboretum in Ohio (Late September)

‘American Gold Rush’ is a compact hybrid cultivar, only 24 inches high compared to the slightly taller ‘Goldsturm’. Bright, yellow-gold flowers cover the plant from July to September and attract lots of pollinators. Black-eyed Susans grow in average, moist, well-drained soils in full sun, although plants will tolerate partial sun (4 hours/day). New plantings prefer supplemental irrigation during dry spells. Established plants are more drought tolerant. Good air circulation is best, so don’t crowd plants together. Deadheading is not necessary as this award-winning cultivar blooms almost continuously into the first fall frost. Plants slowly spread via rhizomes. (Zones 3-9)

Pantone’s 2023 Color of the Year

Posted by Hugh on January 1st, 2023

In case you didn’t already know, Pantone Color Institute has become a worldwide color authority with identifying trendy colors consumers will crave in the New Year. Their Color of the Year selections are often featured in fashion, interior design, outdoor living products and even in landscape plants.

Pantone’s 2023 Color of the Year is Viva Magenta 18-750.

For 2023, Viva Magenta may be more widely used on garden furniture or painting your front door. Perhaps, you may desire to plant magenta colored flowering annuals and perennials on your patio or deck.

Here is a short list of perennials to plant in your landscape that complement the Pantone Color Institute’s 2023 Color of the Year.

Achillea ‘Tutti Frutti Pomegranate’

Agastache ‘Kudos Red’

Coreopsis ‘Lil Bang Red Elf’

Coreopsis ‘Hot Paprika’

Coreopsis ‘Uptick Red’

Crocosmia ‘Lucifer’

Dianthus ‘Fruit Punch’ Cherry Vanilla’, ‘Maraschino’, ‘Pretty Poppers Electric Red’, ‘Paint The Town Magenta’

Echinacea ‘Meteor Red’, ‘Raspberry Beret’

Hemerocallis ‘Double Pardon Me’, ‘Blood, Sweat and Tears’

Heuchera ‘Dolce Cherry Truffles’

Hibiscus ‘Holy Grail’

Hibiscus ‘Mars Madness’, ‘Evening Rose’

Kniphofia ‘Red Hot Popsicle’

Lobelia cardinalis (Cardinal flower)

Monarda ‘Leading Lady Razzberry’

Penstemon ‘Quartz Red’, ‘Cha Cha Cherry”

Phlox paniculata ‘Red Riding Hood’, ‘Starfire’

Sedum ‘Sunsparkler Cherry Tart’, ‘Midnight Velvet’

Spigelia ‘Little Redhead’

Thank You — Nicole Hoonhorst at Walters Gardens & Paul Pilon at BallHort for some plant picks

Raise The Humidity Around House Plants

Posted by Hugh on December 28th, 2022

Tropical plants thrive in a 70-75° F room temperatures during the fall / winter months. Frequently, the central heating system is running at maximum warmth and results in low room humidity. The lush foliage of many tropical plants suffers leaf edge burn and tip dieback caused by low humidity. Here are nine (9) methods listing ways to raise room humidity. You may need to employ two or more methods.

1. Mist Plants Daily

Misting plants is one of the easiest and most interactive ways to raise humidity around your plants. Misting your plants not only raises humidity you’re inspecting them for disease and pest problems and caring for some individually.

2. Place pans and bowls with water nearby your plants

Setting containers of water around plants slowly evaporates water, thereby raising humidity levels.

3. Best Room To Grow Plants

Bathroom, Kitchen, and Laundry are the best rooms to grow house plants. Showering, cooking, washing dishes and drying clothes raise humidity levels on your home.

4. Pebble Trays Boost Humidity

Cafeteria serving trays or old plates and saucers no longer in use, filled with pebbles and small rocks, support pots and plants. The pots do not sit in puddles of water. Excess water between the stones slowly evaporates and raises room humidity. Do not fill too much water in the tray which may lead to root rot.

5. Room humidifier

A room humidifier maintains your apartment or home at a desired humidity level over the fall and winter months. A small portable unit raises a humidity around your plants. You might even be able to set it anywhere in the room to benefit several plant groupings within a large room.

6. Give Tropical Plants Their Weekly Shower

Keeping the bathroom door ajar while showering spreads humidity to adjacent rooms. Also, move plants into a tub weekly and give them a short 3-5 minute shower. It waters the roots, raises humidity, and washes off the dusty leaves

7. Have an aquarium nearby your plants

A nearby fish tank or aquarium sited close to your plants. The water surface gradually evaporates and raises the room humidity levels. Combining a plant collection with an aquarium is a decorative look great looking water plants.

8. Set plants close together

House plants breathe and add humidity to your home. Water evaporates from leaves and soil thereby raising room humidity. Place tropical leafy house plants in close proximity to one another. With certain tropicals, such as orchids and bromeliads, supply higher humidity by employing a multiple of methods.

9. Build a terrarium

A closed terrarium offers an ideal environment to plants demanding high humidity levels. Examples include nerve plant (Fittonia), African violet (Saintpaulia), anthuriums, orchids, and Venus flytraps.

NewGen Boxwoods

Posted by Hugh on December 15th, 2022

Boxwoods (Buxus spp.) are the quintessential shrubs, primarily utilized as a foundation plant, a formal medium hedge, or for low privacy screening. Over the past half century, many new boxwood varieties have been introduced into nursery commerce. Boxwoods work in most landscape situations and are deer resistant. Only a few years ago, boxwood production at U.S. nurseries was greater than for azaleas, hollies, hydrangeas, and arborvitaes.

NewGen Freedom® Boxwoods at Saunders Bros Nursery

Brief History– The impact of boxwood blight (Calonectria pseudnaviculata) on nursery sales has been crippling. Professional landscapers and homeowners could no longer guarantee that the boxwoods they purchased were disease-free. Boxwood relatives, such as Japanese spurge (Pachysandra terminalis), Allegheny spurge (P. procumbens), and Sweetbox (Sarcococca spp.), are also susceptible to boxwood blight.

Additionally, other boxwood diseases and pest problems – namely Volutella canker (Volutella buxii), boxwood leafminer, and midge — have become major concerns here in the U.S. and internationally.

Solution– Plant scientists and nursery growers now have a better understanding about the disease organism that causes Boxwood Blight and how to manage it. The best news is that two highly resistant varieties are now coming to garden centers.

NewGen Independence® Boxwoods at Saunders Bros Nursery

NewGen™ Boxwoods are a new family of boxwoods that offer greater resistance to diseases and pests, as well as incredible landscape performance. After many years of testing in the landscape, production, lab, and trial gardens across the U.S., Saunders Bros Nursery has debuted two boxwood varieties that are Boxwood Blight resistant. This wholesale nursery is located in Roanoke Valley area in central Virginia,

NewGen Independence® (PP28888) is a mid-sized boxwood highly resistance to both Boxwood Blight and boxwood leafminer. It has glossy deep green foliage and a medium rounded growth habit (@ 2 to 4 inches per year, nearly as tall as wide). Size: 15 years (3 feet tall and 3 feet wide) 25 years (4.5 feet tall and 4.5 feet wide). Substitutes for: English Boxwood (Buxus sempervirens ‘Suffruticosa’), ‘Green Beauty’, ‘Green Velvet’, and ‘Green Mound’. (Zones 5b-8).

NewGen Freedom® is highly resistance to Boxwood Blight and to boxwood leafminer. It grows vigorously @ 3 to 6 inches per year along with lovely glossy medium green foliage. Size: 15 years (3.5 feet tall and wide); 25 years (5 feet tall and wide). grows slightly taller than wide. Substitutes for: ‘Wintergreen’, ‘Winter Gem’, ‘Jim Stauffer’, ‘Green Mountain’. (Zones 5-8).

Creating A Tropical Look

Posted by Hugh on December 8th, 2022

Here are some ideas for designing a tropical landscape in your yard. Start with large leafy trees that are hardy in zones 6-7 include catalpa (Catalpa spp.), hickories (Carya spp.), some oaks (Quercus spp.), large leaf maple (Acer macrophylla), American sycamore (Platanus americana), American linden (Tilia americana), and Empress tree (Paulownia tomentosa). In zones 7-9 add Chinese parasol tree (Firmiana simplex), and in zones 8 -10 add Mexican sycamore (P. mexicana).

Enormous leaves of Paulownia (Empress tree) cutback

Big leaf magnolias are also tropical looking. These five underplanted magnolias are highly dependable trees in large landscapes — Bigleaf (Magnolia macrophylla), Ashe magnolia (M. ashei), (M. tripetala), and cucumber magnolia (M. accuminata). Four of five species are U.S. natives.

Large 20+ inch long leaves of *Magnolia macrophylla*

Have a small landscape? Cutback these young trees in late fall and new spring growth will sprout with much larger leaves and will not flower.

Hardy bananas (Musa basjoo) and angel trumpets (Brugmansia) thrive zone 7 hardy and in protected areas of zone 6b. Protect the roots and crowns with a winter blanket of mulch or pine needles. Both species dieback to the ground surface in fall.

GROW TROPICALS AS ANNUALS – Leafy tropical favorites such as papyrus (Cyperus papyrus), caricature plant (Graptophyllum pictum), elephant ears (Colocasia ‘Thailand Giant’), and variegated tapioca plant (Manihot esculenta ‘Variegata’) grow rapidly. Buy young vegetative plants to pre-started in a warm greenhouse @ minimum 60°F temps prior to safely planting outdoors when the frost threat has passed. Some of these tropical plants finish the growing season @ 4-8 feet high and wide and die off with the arrival of a wintry chill (USDA hardiness zones 9-11).

What’s New At Your Local Florist Shop

Posted by Hugh on December 1st, 2022

What’s New At Your Local Florist

Your local florist shop…that is often the first place you think of when gifting something green and flowery to an ailing friend. Besides the standard florist shops, most supermarkets contain a florist department. Check out the recently published USDA Floriculture Crops Report. It lists most of the potted plants and cutflowers available for purchase at florist shops.

Let’s start with the winter holiday gift giving market. Poinsettias are still the the most popular item, available in lots more colors and size categories, followed by kalanchoes, Christmas (Zygocactus) and Thanksgiving (Schlumbergia) cacti, cyclamen, and assorted tropical foliage, all wrapped in decorative ribbon and foil are popular. Shoppes are stocked during the Easter season and Mother’s Day with traditional items–lilies, florist azaleas, begonias, florist potted roses, and hydrangeas, plus spring flowering bulbs (tulips, hyacinths, daffodils, crocus and others).

In the orchid world moth orchids (Phalaenopsis), lady slipper (Paphiopedilum), Dendrobium, Cattleya, Oncidium, and others are available year-round. Next up are seasonal potted items such as spring flowering bulbs (tulips, hyacinths, lilies, daffodils, crocus and others), Easter lilies, combination planters, florist hydrangeas (non-hardy), tropical hibiscus, potted mums, begonias, and florist potted roses.

Other notables flowering plants, more seasonal in nature, are florist azaleas, gardenias, kalanchoe, Gerbera daisy, anthurium and cyclamen. Several potted crops are niches in the florist industry like African violets, cacti, sedums, and mini begonias. Summer sales are taking off with potted sunflower, regal pelargonium, primula and alstroemeria. Notable inventory items include some perennials — dianthus, lavender, salvia, and sedum.

Depending in what region of the country you live in, winter items may include cineraria, exacum, gloxinia, and streptocarpus (cape primrose), calceolaria, Christmas cherry and Christmas pepper, and Fuchsia have moved to the bedding/garden plant segment. Bromeliad, cacti, and succulents, and snake plants (Sansieveria) are now a part of the foliage plant segment.

The cut flower list has recently expanded. It already includes pompon mums, dahlias, gerbera daisies, gladioli, irises, orchids, peonies, roses, snapdragons, sunflowers and tulips, but lisianthus (Eustoma), aster, delphinium/larkspur, protea and wax flowers have been added.

Finally, miscellaneous florist items now include campanula, celosia, and ranunculus. Popular bedding plants also make decorative potted plants: calendula, crossandra, dianthus, gomphrena, ornamental oregano, osteospermum, torenia, and zinnias– complete with foil and bows for gift giving.

Protect Plants from Deer And Other Critters

Posted by Hugh on November 29th, 2022

In many suburban and urban areas, often to their detriment, deer are hungry to eat several of your landscape plants. No two gardens are alike, and deer may browse on different plants in your neighbor’s yard. You must employ your own plan (strategies) to protect landscape trees, shrubs, and perennials from deer foraging.

Fencing is the most effective barrier method to deter deer, but it can be costly. Steel and wooden fences should be at least 8 feet high. Alternative deer fences can be constructed of affordable rolls of plastic or wire mesh. Hungry deer may breach flexible barriers because they don’t like jumping into an area they can’t see.

Some municipalities have passed codes limiting fence heights to 5 feet which many deer will jump over. Choose fencing that is aesthetically pleasing, offers privacy, and can be customized to compliment your outdoor space and the architecture of your home.

There are several ready-made foliar repellents that deter deer and other critters because of their unpleasant odor or taste. However, repellents are only effective short-term and must be reapplied. The chemicals often wash off after heavy snow or rain. Purchase 2-3 different products as critters become accustomed to the same deterrent. Heed proper precautions when applying repellents. Follow the label directions and wear safety goggles and a mask when applying.

You should safeguard young trees and shrubs, particularly those planted over the past three years. Trees need to gain height, trunk caliber, and vigor. Small critters include rabbits, mice, voles, and other rodents. In winter, rodents may gnaw on the thin bark of young trees and shrubs; they love their sugary sap. Corrugated or plastic tree guards and wraps provide good winter relief but should be removed at the start of spring and reapplied in late fall. Otherwise, wood boring insects may nest year-round inside.

Individual tree guards made from biodegradable plastic mesh tubing or loose-fitting plastic sleeves, and chicken wire fencing are effective against rodent damage. In most situations, provide adequate protection to the lower 24 to 36 inches of the tree trunk. If necessary, remove snow buildup from the base of the tree to prevent critters from gnawing upper branches.

Bury the bottom 3 to 5 inches below the ground or pin the fencing with U-shaped anchor pins to prevent rabbits and rodents from burrowing under.

Large Bulbous Alliums

Posted by Hugh on November 21st, 2022

The huge ornamental ball-types flowering onions (Allium spp.) are standouts in the late spring/early summer garden (Zones 5-9). Bulbous alliums are both architectural and colorful wonders. Bulbs are planted in the fall.

Bulbous alliums require full sun for best growth. They make stunning garden borders, beds, and cottage gardens. They have a major visual impact when several are planted en masse. Alliums also tolerate a wide variety of soil and are drought tolerant.

They perform at their best in a soil that is humus-rich, well-drained, moist but not wet, and a porous sandy loam. Soil pH may be acidic, neutral, or alkaline. Ideally, alliums thrive organic rich sandy soil, but do well in clay soil with good drainage.

Let’s take a closer look at 8 popular bulbous allium (listed alphabetically):

Purple Sensation (A. aflatunense) is a crowd favorite (cost effective) for its deep blue, round ball shaped flowers that are small, star-shaped, and rich violet-lilac color. Flower stems grow to a height of 20 to 30 inches. Add to that their sturdy stalks arising the blue-green, strap-like, handsome leaves. The long-lasting blooms from late spring into early summer. As a cut flower, blooms can last for as long as 2 weeks!

Ambassador has large intense reddish purple softball size flowers on sturdy stems 3-4 feet tall.

Gladiator struts lilac-purple florets within softball-size flower heads on stems that stand 2-3 feet tall.

Globemaster (A. christophii and A. macleanii) grows 3- to 4-foot flower stalks that support large 8- to 10-inch diameter flower globes.

Mount Everest has baseball-size white flower-heads consisting of 50 or more flowers. Flower-heads are 5- 6 inches wide, and atop 3 feet tall sturdy stems. Its basal leaves are strap-shaped and grayish-green.

Star of Persia (A. cristophii) grows 24 inches in height, emerging from glaucous, strap-shaped basal leaves. Globular flower heads are rosy-violet in color and measure 8 inches across.

A. schubertii boasts huge globe-shaped 12-15 inch loose, spidery flowers, as many as 100 tiny star shaped flowers which are only 20 inches tall.

Drumstick Allium (A. sphaerocephalon) is a charming species which produces vibrant colored blooms; lime-green flowers gradually transition to crimson to reddish brown in color.

Allium blooms attract honeybees, butterflies and other pollinators depending on variety, select from white, pink, or purple ball-shaped flowers. Maybe best of all — they’re deer resistant.

I find the best selection of bulbous alliums at Brent and Becky’s Bulbs in Gloucester, VA. Visit their website: www.brentandbeckysbulbs.com

Purple Beautyberry

Posted by Hugh on November 14th, 2022

Purple beautyberry (Callicarpa dichotoma) is a compact, deciduous, woody shrub with showy ornamental fruits that may last long after the shrub has dropped its leaves in fall. Beautyberry is among the finest ornamental fruiting shrubs and easy to care for.

Purple beautyberry is a native of China, Japan, Korea, and Vietnam and is in the mint family (Lamiaceae). Several other species of Callicarpa are found worldwide. (Zones 5-8). In cold USDA Zone 5 winters, stems may die back to the ground with new growth emerging from the shrub base in spring. Plant several for adequate cross-pollination and more numerous fruits.

Purple beautyberry with heavy fruit load

This Asian form typically grows 2 to 4 feet high and 4-5 feet wide. Beautyberry prefers full day sun to guarantee lots of flowers and fruits. Under too much shade, branches become leggy and less fruitful. Plant in well-drained soil and irrigate during seasonal dry spells. Beautyberry becomes quite drought tolerant after its initial planting year.

Clusters of pink to lavender flowers emerge in late spring and summer on new wood, followed by clusters of lilac-violet berries that ripen in September through October. In late winter or early spring prune to the desired shape and size. An alternative pruning step is to cut all stems back to 6 inches in late winter, particularly if winter has been unusually harsh.

Leaves are smaller, aligned closer together on branches and fine-textured compared to large coarse-leaved American specie (C. americana) — that is also taller-growing. Compact growing Asian beautyberry makes a better fit for growing in large patio containers.

When properly sited and cared for, disease and insect problems are rarely observed. Otherwise, fungal leaf spot, mildew, stem cankers, and black mold may become troublesome.

Beautyberry flowers attract bees and butterflies, and birds and small mammals are attracted to the fruits. It is also deer resistant.

Four of the Finest Cultivars:

‘Early Amethyst’ grows to 3-4 feet tall and 4-5 feet wide. Light pink flowers are followed by large clusters of bright, glossy, 1/8 inch wide, amethyst-purple fruits earlier (late August -November). Fruits often persist into winter and can be a prolific seeder (weedy?).

Pearl Glam™ (C. dichotoma x C. kwangtungensis) is an upright growing form with dark purple foliage and an early fruiting display. This compact plant grows to a mature height of 4 feet tall and 3 to 4 feet wide.

‘Issai’ grows to 2-3 feet high and bear lilac-violet fruits earlier.

‘Duet’ (f. albafructus) – 6 feet tall and wide deciduous shrub bearing medium green foliage with creamy yellow margins and an eye-catching display of pure white berries.

Caution: American beautyberry is a better choice in States that list C. dichotoma as invasive.

Poison Ivy

Posted by Hugh on November 4th, 2022

“Leaves of three, let it be”. Parents teach their young children about this green plant menace — Eastern poison ivy (Toxicodendron radicans). The plant is familiar to hikers and gardeners alike.

Poison ivy is native throughout the United States and much of southern Canada and can be found in a wide variety of places from woodlands, fence rows, roadsides, and home landscapes. Contact with any part of the plant- leaves, stems and roots can produce an insanely itchy rash or skin swellings that can be linger over 3-4 weeks.

In sunny areas poison ivy can appear as a bushy, erect or trailing landscape shrub or as a climbing vine in the woods. As a woodland vine, it can attach tree trunks and climb via aerial rootlets. Poison ivy contains a toxic oil called “urushiol” that causes a skin allergy (dermatitis) to most humans and some pets. Infection can occur from direct contact with the plant, indirect contact (e.g., dog, rake, or shoes) or from breathing smoke from a fire of plant material. Some humans seem to be immune.

As a woody shrub, it can reach 6 feet high and upwards of 60 to 100+ feet tall attached firmly by rootlets to trees, walls, or fences or trail along the ground. Birds, reptiles, deer, and amphibians can eat the plant and its berries and use the plant as shelter. A variety of insects feed on the flowers of poison ivy too – from beetles to flies, bees, wasps, ants, and butterflies.

Each compound leaf is arranged in groups of three. The middle leaflet is longer than the outer two. Their shape and size may vary from smooth, rounded edges to serrated edges to shallowly lobed edges. Poison ivy leaves are shiny and bright green in spring, green and less glossy by late summer, and turn red or reddish yellow in fall. Plant may be mistaken for Virginia Creeper (Parthenocissus quinquefolia).

Virginia Creeper Mistaken for Poison Ivy

Poison ivy can be removed by either mechanical means– such as by repeated mowing or pulled with gloved hands. An alternative is to apply specific herbicides to freshly cut stumps (within 36 hours). Herbicides are most effective in late summer and multiple applications may be needed. Read and carefully follow the label as these chemicals are harmful to many nearby landscape and garden plants. Here is a short listing:

Roundup (Glyphosate) – kills poison ivy and many other herbaceous and woody weeds; shield nearby desired plants.
Weed-B-Gon (2, 4-D) – kills many broadleaf weeds including poison ivy but does not injure grass.
Spectracide Weed Stop (2, 4-D, MCPP, & Dicamba) – apply against broadleaf weeds; will not injure grasses.
Weedazol (Amitrole) – available in either liquid form or a wettable powder.

Do not burn poison ivy as the fumes are as toxic as the oils that get on skin. Also, avoid weed wacking. Wear work clothes that protect legs and arms and safety goggles over eyes. Launder all work clothes separately from other garments.
MT Cuba Center in Greenville, DE lists the benefits of poison ivy…more than 60 species of birds eat its fruit, and many pollinators frequent its blooms.