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

Precise Care For Calatheas

Posted by Hugh on January 24th, 2023

Calatheas, also called Peacock plants, are among the most beautiful of foliage house plants, but their care can be challenging. Plants prefer low to medium bright spot in your home and look their best away from direct sunlight. The key to success is high room humidity and are best paired up with similar tropical favorites like philodendrons and Phalaenopsis orchids.

Select plastic, terra cotta, or ceramic containers. The pot should be two inches wider than the one it was purchased in. Grow calatheas in a humus-rich peat /bark /perlite growing media that retains moisture. The soil needs to be moist much of the time to permit roots to breathe. Calathea roots love moist soil but resent overwatering or letting pots set in saucers of water over long periods; this often leads to root rots and eventual loss of the plant.

Houseplants need a regular dose of fertilizer to look their best. The best time to fertilize is when the plant is actively growing; for most plants that means fertilizing in the spring and summer (mid-March to mid-October).

*Calathea lancifolia* (Rattlesnake Plant)

Feed calatheas a weak solution of fertilizer and be careful not splash fertilizer on their sensitive foliage. Calathea leaves are highly sensitive to chemical burn. Similarly, over-fertilizing your Calathea could cause the roots to burn, and this will slowly kill the plant.

Calatheas are susceptible to few pests, principally spider mites and mealybugs. Inspect plant(s) regularly and treat pests is to clean the leaves with a mixture of water and dish soap in a spray bottle. As houseplants calatheas are not harmful to pets and young children. Pruning-wise, remove old worn leaves that have lost most of their decorative color(s).

Plants hobbiests are currently witnessing a calathea renaissance. Some leading varietes are: C. lancifolia (Rattlesnake plant), C. orbifolia, C. ‘Roseopicta’, C. veitchiana ‘Medallion’, and C. zebrina (Zebra plant).

Propagate your plant by separating the plant’s root mass with a sharp knife.

Calatheas are not harmful to pets and young children.

Growing Jewel Orchids

Posted by Hugh on January 12th, 2023

Jewel Orchids (Ludisia discolor) are native to the tropical forests of Southeast Asia. Compared to the tree-climbing epiphytic Phalaenopsis and Cattleya orchids, Jewel Orchids are terrestrial plants that grow on tropical forest floors. Jewel orchids are grown primarily for their spectacular dark and colorful veined ovate foliage and secondarily for their flowering.

Jewel orchid at Biltmore Estates in Asheville, NC

Jewel orchids grow in low light and high humid environs; their roots grow in soil-less media containing sphagnum peat moss or coarse bark. Consider them as low light house plants in 80%-90% shade. Leaves feel velvety and are quite decorative with red-white or golden veins; leaf colors are burgundy to maroon to richly green.

Jewel orchids bloom once yearly, primarily in winter. Plants produce clusters that rise up on long floral spikelets above the dark exotic foliage. Jewel orchids grow well in well-drained, slightly damp soils. You need to lightly fertilize every 2-3 weeks during the spring-summer growing season and half that in late fall and winter months.

Flowering is something to look forward to. Small white flowers appear on long spikes that shoot up. Flowers may lack fragrance, but the bloom stalks are lovely over 4-5 weeks.

Common growing problems are twofold: 1. root rot, likely caused by overwatering or poor media drainage, and 2. brown, curling leaves caused by low humidity or excess light. Foliage spotting is an early symptom; follow up immediately to alter the plant’s environment.

Jewel orchids are not commonly available local garden centers but are sold at on-line plant sources. Two genera – Ludisia discolor and Macodes petola – are popularly listed online. L. discolor ‘Alba’ – leaves are bright green with white veins and white flowers.

There are other genera of jewel orchids to collect: Ludochilus, Anoectochilus, Dossinochilus, and hybrids thereof. Lightning Bolt Jewel Orchid (Macodes petola (velvety leaves / silver veins) and Lava leaf orchid (M. sanderiana x limii).

Jewel orchids are fast growing and make terrific terrarium plants. Repot the plant annually to refresh the soil.

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