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

Bigleaf Magnolia

Posted by Hugh on March 6th, 2022

Bigleaf magnolia (Magnolia macrophylla) is a deciduous, native tree that reaches 30-40 feet tall. This unusual pyramidal tree magnolia is rarely found in the wild, inhabiting a few rich wooded areas in river valleys in the southeastern U.S. (USDA hardiness zones 5-8). With age, the tree develops a spreading rounded crown.

Bigleaf magnolia is a unique landscape feature. This deciduous magnolia bears the largest flowers of any tree in North America. Its enormous-size mature leaves are green above and silvery-gray below that can be up to 36 inches long and 12 inches across. You find the tree growing in cool moist mountainous habitats and in mildly acidic soils.

The cream-colored goblet-shaped blooms open to 8-10 inches across, and emit a delightful fragrance up close in late May. After flowering, the seed pods swell with seeds covered in a protective red seed coat.

Cultivars are rare – ‘Palmberg ’ (with slightly larger flowers) and ‘Purple Spotted’ (flowers with purple stain at their base). For most people the place you see the first bigleaf magnolia is at a regional botanical gardens in the Mid-Atlantic and Southeastern U.S.

The huge flowers are often located far off the ground and are not always easy spotted from the ground. Flowers give way to spherical cone-like fruits which mature to red in late summer, releasing individual red coated seeds attached to slender threads.

Its large foliage limits its use in many urban landscapes. Bigleaf magnolia grows best in moist, organically rich, well-drained loams in full sun to part shade. Generally intolerant of soil extremes (dry or wet) as well as most urban pollutants. Best sited in locations protected from strong winds which may shred the large leaves.

For the patient gardener, the tree likes to get its roots established before adding on lots of vegetative shoot growth. The first blooms may not appear for 12 or more years. Bigleaf magnolia is hard to purchase in the garden marketplace. Search for young seedlings at native plant emporiums online.

Landscape Site: moist woodlands

Ridding Homes Of Camel Crickets

Posted by Hugh on February 26th, 2022

Camel crickets, also known as cave crickets or spider crickets live in dark damp places of the home or garage. They are related to grasshoppers, locusts, and other crickets (insect order Orthoptera) and are six legged as opposed to spiders that have eight legs. Fully grown adults range in size from 1-2 inches long, while the nymphs, the immature stages, have the same body type at a smaller scale, and no wings.

Camel crickets are strong jumpers, thanks to their long hind legs, and do not have wings. Camel crickets do not bite and their chewing mouthparts gnaw on just about anything, including fabrics, wood, cardboard, plants, and other bugs.

Camel crickets are often seen in eastern and Midwest states. These pests dislike the cold damp and tend to make their way indoors when the weather is hot and dry in the summer and fall months. They can breed in your house if the conditions are right, and may be seen any time of year. They will feed on fungi, wood, cardboard, fabrics, and other spider crickets.

Prevention and eradication of spider crickets is to keep them out of your home in the first place. Basements and crawl spaces are popular hangouts for them. Seal around entry doors and basement windows and ground-level doors with weather stripping. Dehumidifiers make room air less damp. Toss away old cardboard boxes and newspapers will also help.

Sticky insect traps are available at home stores. You can make your own from a few loops of duct tape. Place these where walls and floors intersect in basements and attached garages. Shallow bowls of soapy water also make effective traps. Camel crickets will fall in the bowl and drown. The key method of managing these household pests is to reduce the moisture inside your home. They are attracted to water and high humidity.

Use a shop vacuum to suck them up and empty it out immediately. Otherwise, they will crawl out and re-infest your home.

Hardy Zone 6 Camellias

Posted by Hugh on February 21st, 2022

In the Southern U.S., camellias are treasured for their showy flowers in the fall-winter landscape. Their glossy evergreen foliage looks great all year long. Hardy varieties are now available for zone 6 northern gardens (-10 to 0 °F). Essentially, gardeners can raise camellias in Tennessee, Kentucky, Virginia and in most coastal cities along the East Coast. Blooms measure 3-5 inches across with yellow stamens in the floral centers.

Depending on variety, flowering may last for a period of 4 to 6 weeks. Sudden drops of temperatures may injure blooms currently opened and those due to open a few days; hence, flowers in tight bud often survive, swell, and open. Color choices include shades of red, pink, lavender, white and even multi-colored. Varieties vary in size, from 8 -15 feet in height and 6 – 10 feet in spread. Spring pruning can alter plant dimensions.

Camellia likes a well-drained, mildly acidic soil along with adequate soil moisture. In northern areas grow shrubs in a partially sunny location or one with full morning sun and afternoon shade. Established camellias are moderately drought tolerant; irrigate during prolong dry spells in summer and fall. Fertilize camellias in early spring with a product labeled for acid-loving shrubs. Prune camellias after seasonal blooming is over or in mid-spring.

Shishi Gashira camellia is an outstanding flowering shrub. Looks-wise, in leaf and flowering, this camellia mimics our Sasanqua camellias, but is actually Camellia hiemalis. It has a mature compact height of only three feet. and is an ideal choice for smaller landscapes. Foliage is highly glossy and leathery along with gorgeous semi-double, rose-pink blooms. Shishi Gashira is a winter bloomer with great cold tolerance.

‘Cleopatra’ camellia blooms in October – November

Modern day zone 6 camellias are interspecific crosses between C. oleifera, C. sasanqua, C. hiemalis, C. japonica, C. vernalis selections. Some start blooming in early fall into very early winter and a second flower in March and April. Petals are shed and require no dead-heading. In northerly climes, zone 6 hardy camellias should be planted and mulched from early spring up to Labor Day (and no later).

Reward yourself by planting two or more camellia in your garden to flower during the transition period in early fall and in late winter when temperatures are seasonally mild. Here are some favorites:

Fall Bloomers: ‘Snow Flurry’ (white), ‘Autumn Pink Icicle’ (clear pink), ‘Sweet October’ (white / pink tinge), ‘Winter’s Joy’ (pink double), and ‘Long Island Pink’ (light pink), ‘Cleopatra’ (soft pink).

Mid-March/April Bloomers: ‘Pink Icicle’ (shell pink), ‘April Tryst’ (deep red), and ‘April Remembered’ (pale pink-large flower), ‘April Rose’ (deep rose pink).s

Uniqely Different Chinese Quince

Posted by Hugh on February 16th, 2022

Chinese quince (Pseudocydonia sinensis) is an under-utilized small 10-20 feet tall deciduous tree or large shrub with a dense oval crown (USDA hardiness zones 5-8). Initially, it starts out a slow grower for 1-2 years to establish its roots. Throughout the year, it provides several months of landscape charm that includes an attractive form, large edible fruits, and a stunning patchwork bark in fall and winter.

Chinese Quince (Pseudocydonia sinensis) at NC Arboretum Bonsai Collection

The finely edged, oval shaped, 3-4″ dark green leaves emerge in late March and April. The foliage stays blemish-free through summer and turns yellow to red in fall. Showy cup-shaped, fragrant pink flowers (to 1 1/2″ across) bloom in April-May. They resemble the blooms seen on the more popular Japanese flowering quince (Chaenomeles speciosa).

Huge (5 – 5½” wide) oval quince fruits ripen in fall (October) and are sweetly fragrant in aroma. Fruits are edible off the tree and can be made into jams and syrups. Unpicked fruits may become a trashy headache. Ripen fruits fall from the tree, break open, and rot. The decaying fruits emit a foul odor that attract wasps and other insects.

During the remaining autumn and winter season, your eyes will delight at the tree’s patchwork bark. The flakey, sycamore-like trunk exfoliates to expose brown, orange, green and gray hues.

Chinese quince is a good planting choice in small landscape places. It is easily grown in average well-drained soils and in full sun. The tree tolerates poor soils and moderate drought, but prefers fertile, moist, well-drained, mildly acidic loam soil. Site in winter protected locations (southern side of walls) in the northern part of its zone 5 growing range.

Chinese quince is available primarily from specialty nurseries online and generally not sold at local garden centers.

Fireblight can be a serious disease problem in areas of the U.S. in some years.

Japanese Cornel – Notable Cultivars

Posted by Hugh on February 11th, 2022

*Cornus officinalis* at Biltmore Estates in Asheville, NC

Starting in late February, Japanese cornel (C. officinalis) burst into bloom with clusters of yellow flowers (zones 5–8). Native to Japan, China, and Korea, this lovely small tree (or large shrub) is one of a few plants that is an early harbinger of spring. Here are notable cultivars:

‘Sunsphere’ grows 20-25 feet high and is an exceptional heavy bloomer with its bright yellow flowers. Sunsphere was found and named by Mike Stansberry in Knoxville, TN. Flowers are rarely injured by low night wintry temperatures still common in late February and March across the Southern Appalachian region (USDA zones 6 and 7). This small tree can be purchase from Beaver Creek Nursery in Knoxville, TN as well as from other on-line nursery source

‘Kintoki’ Japanese cornel dogwood (Cornus officinalis ‘Kintoki’) is another fine selection. Kintoki grows more as a large shrub than tree-like @ 15 to 20 feet tall and wide. Training this shrub into a small tree is not difficult. Early spring masses of brilliant yellow blooms are followed by stunning red, cherry-like fruit that ripen in late August.

Kintoki is rated as one of the better cornelian cherries in the southeast U.S. The plant is notable for its heavy flowering, exceptional high gloss seasonal foliage, and exquisite exfoliating bark that gets better with the passing of time.

Japanese cornel grows in any average well-drained soil and in full sun to partial shade. Spring-summer foliage is dark green, and autumn colors varying from light yellow to reddish purple before falling. As the grayish outer bark ages, it chips off in tiny strips, exposing the yellow-orange inner wood. In late summer the cherry red drupe fruits have colored up and are consumed by foraging birds.

Eleven Popular Perennials In The U.S.

Posted by Hugh on February 6th, 2022

Today’s most popular perennials are ones asking for low maintenance and have few to no bug or disease problems. Cutflowers may be used in fresh cut and in dried arrangements.

Coneflowers (Echinacea x) – native coneflowers are tough and pretty; flower colors: purple, white, orange, red, yellow. Compact coneflower series (16 to 30 inches tall): Sombrero®, Artisan™, PowWow®, and Cheyenne Spirit® for non-stop blooming June to September; spent flower cones visited by goldfinches or other birds over winter. (Z 4-9)

Black-Eyed Susan (Rudbeckia) – heavy-blooming native perennial from early summer to frost. Highly recommended new cultivar ‘American Gold Rush’ is disease resistant, heavy bloomer, and should not reseed all over your garden. Deer-free and drought- and heat- tolerant. (Z 3-9)

Hostas (Hosta spp.) also known as plantain lily – the leading shade perennial prized for their large, tropical-looking leaves that come in an array of sizes, shapes, and colors ranging from chartreuse to blue-green to bicolor. Floral spikes of white, lavender, or pale purple appear over the summer months. (Z 3-9)

Daylily (Hemerocallis) varieties are available in almost shape, size and color imaginable. Daylilies are exceptionally dependable long-lived perennials. Ask local gardening friends for a list of their regional favorites. (Z 3-9)

Bee Balm (Monarda) aka Oswego Tea – this old-fashioned perennial beloved by gardeners is visited by hummingbirds, butterflies and bees. Flowers come in red, pink and lavender all summer long if deadheaded. Try tall-growing ‘Jacob Kline’ for its 3+ feet high, mildew-resistant, scarlet red flowers and new compact (14-18 inches) Pardon Me® series. (Z 4-8)

Herbaceous Peony (Paeonia) – one of grandma’s favorites and currently enjoying a resurgence in popularity. Flowers are outrageously gorgeous, some varieties measuring 10 inches across. Color range of white, red, purple, peach, and many pink shades. (Z 4-7)

Red Hot Poker (Kniphofia), aka Torch Lilies and Tritoma – prized for their tall, show stopping flower spikes in bright red, orange, yellow, and other colors; full to partial sun and well-drained soil. Cultivar sizes range from dwarf (14 inches) to tall 3 feet tall. Popular series include Pyromania™, Poco™, Popsicle™, and Echo™. (Z 6-9)

Tall garden phlox (Phlox paniculata) stand tall height and invite butterflies to large, fragrant clusters of pink, red, purple or white flowers from mid- to late- summer; select powdery mildew resistant varieties like ‘David’, ‘Glamour Girl’, and ‘Jeana’. (Z 3-8).

Shasta Daisy (Lecanthemum x superbum) – bright white or creamy white daisy blooms such as ‘Becky’, ‘Whoops-a-Daisy’ and ‘Banana Cream ll’ in early- to mid-summer. (Z 5-9)

Lenten Rose (Helleborus x) – winter bloom from late December (H. niger) onward into early April and these evergreen perennials are usually deer resistant. Their single or double flowers welcome pollinating bees back into your garden. (Z 4-9)

Daffodils (Narcissus) – prized for their cheerful yellow/white, trumpet-shaped flowers that herald the arrival of spring. Plant bulbs in fall and they bloom for many springs to come; hundreds of types of daffodils to select from yellow, orange, white, and bicolors. (Z 3-9)

Create A Garden With Four Seasons Appeal

Posted by Hugh on February 1st, 2022

Winter blooming paperbush (*Edgeworthia chrysantha*)

‘Winter King’ hawthorn laden with fruits on a cool February day

Your garden should be a year-round enjoyment and you should design it to reflect that. Many trees and shrubs offer multi-seasonal attraction. Several years back I designed a series of walking paths to network through my garden to capture its 12-month natural beauty.

Planning next year’s garden? Look for calendar gaps in your own landscape and what plants fill that gap of time. Choose an outdoor site where the seasonal enjoyment can be viewed from inside your home. For example, plant Japanese maples, flowering dogwoods and cherries, summer flowering hydrangeas and Rose of Sharons (Hibiscus syriacus), and fall-winter flowering camellias and colorful holly berries within view from a patio window so you may enjoy it seasonally from inside the warmth of your home in winter.

On a frigid wintry day, curl up with a good book indoors while staring out a window at the vee-branch architecture of a clump river birch or crape myrtle, the mid-winter flowering Chinese paperbush (Edgeworthia) that may be enjoyed all four seasons. During February-March, vernal and Chinese witchhazels are blooming; winter aconites (Eranthis) and snowdrops (Galanthus) are in flower, and daffodils, crocuses, and other bulbs are poking through.

What about planting trees and shrubs with brightly ornate fruits over the fall and winter seasons. ‘Winter King’ hawthorn (Crataegus viridis) or winterberry holly (Ilex verticillata) are loaded with ruby red fruits. Plant a tree with attractive winter bark such as redtwig dogwood (Cornus stolonifera), flowering cherry (Prunus x yedoense), or paperbark maple (Acer griseum) nearby a window to be viewed from indoors on a cold or snowy winters day. How about the gray muscular bark of native hornbeam (Carpinus carolinana) or the vertical architecture of ‘Slender Silhouette’ sweetgum.

Enjoy your garden 12-months a year. Invite nature indoors by filling vases with dried flower heads from hydrangeas, various perennials, or ornamental grasses to decorate a table or mantle. How about trekking through the winter garden with hot chocolate in hand. Construct a series of walking paths made from wood shavings, pine needles, chat (fine gravel), or 16-18 inch concrete squares.

Fresh Spring Foliage of ‘Purple Ghost’ Japanese maple

Lacebark Pine

Posted by Hugh on January 28th, 2022

Lacebark pine (Pinus bungeana) (USDA hardiness zones 4-8) is arboreal mid-sized gem is a lovely 3-needle pine. It is a slow-growing pine with an absolutely exquisite exfoliating patchwork bark which becomes more attractive as the tree ages. Some of the best specimens that I have witnessed are planted on the New York Botanical Gardens in the Bronx, NY.

Lacebark pine grows into a 30-50 feet tall pine with narrow upright branching. Gardeners and landscapers may start out planting an affordable 2 – 3 feet multi-branched shrub. The slow growth rate, initially 4-5 inches annually, almost doubles after 4-5 years on-site. The lovely cinnamon-colored candles tip the branches in May, similar to candles decorating a cake. When fully expanded, 3 needle clusters -long bristly needles measure 2-3 inches long and are sharp to the touch.

Lacebark requires no special care other than fertilizing in the early spring and mulching until it is established after 2 years. Plant lacebark in full sun and above-average garden soil that is well-drained. An older tree exhibits moderate drought tolerance.

Bark mottling begins after 8-10 years, but the real show is many more years away down the road. A young patient gardener may opt to prune off a few side branches for a peek of the exfoliating bark pattern within. Young tree bark tends to color olive green and gradually bleaches out to milky white many years hence.

Most potentially serious disease and insect pests may be avoided through wise siting and care. This is a specimen that must be sited. Select a visible landscape location which is frequently visited, such as near a patio, carport, driveway or a window which looks out at lacebark.

Two highly rated cultivars are ‘Rowe Arboretum’ and ‘Compacta’, both known to mature more compact size-wise. A third multi- trunked form is ‘Silver Ghost’; these multi-trunked forms exhibit exfoliating bark green bark color with irregular whitish or brownish patches. The bark is dotted much more white patching than the species.

Lacebark pine and cultivars can be purchased from specialty mail-order nurseries via the internet. Mature height and width of cultivars are 20 feet by 15 feet. Lacebark is a long-term investment, an evergreen that you and future generations will cherish for its exquisite patchwork bark.

More Cool Small Flowering Shrubs

Posted by Hugh on January 23rd, 2022

For many urban gardeners, landscape space is very limited. Here are several showy shrub choices along walkways and perennial border, and in deck and patio containers. Each year the list of dwarf shrubs continues to get longer. They are low maintenance, including very little annual pruning.

Shrub Roses – like Drift™ and Flower Carpet™ roses- are just excellent example. These perfectly shaped tiny roses have mostly clean, healthy foliage that stay under 2 feet in height (zone 4-9). They are moderately resistant to rose rosette virus. Some gardeners grow them as perennials.

Small hydrangeas like Tiny Tuff Stuff and Wee White smooth hydrangeas, Date Night weigela, dwarf chaste tree (Vitex), and several more that are newly introduced. Here are some featured tiny shrubs that you’ll like.

Date Night™ Electric Love’ Weigela – only 2-3 feet tall and 3 feet wide compact and vibrant red flowers and dark green foliage; plant it along a walkway or as the star of a decorative patio pot (zones 4-8).

Fine Wine™ Weigela is a shorter version of the variety Wine and Roses, only 2-3 feet tall and wide, deep burgundy foliage and deep pink spring flowers, that will re-bloom in summer (zones 4-8).

Invincibelle Wee White™ Hydrangea (Hydrangea arborescens ‘NCHA5’) produces large pure white flowers from early summer to frost, held upright on sturdy stems; forms a neat 2-3 feet mound (zones 3-9)

Tuff Stuff™ Hydrangea (Hydrangea macrophylla var serrata ‘MAK20’) grow only 2 – 3 feet high and wide with large, heart-shaped, bright green serrated foliage in spring and summer, that turns rich shades of bronze, burgundy, and carmine in autumn; lacecap pattern of tiny fertile flowers (dark red) in a cluster surrounded by larger, sterile florets (magenta-pink) flowers most of the summer. (zones 5-9).

Bobo Panicle Hydrangea (Hydrangea paniculata Bobo) -3-4 feet tall with white flowers that start blooming in mid-July in Tennessee.

Bellini™ Crape Myrtles (Lagerstroemia indica Bellini™ – compact series that bloom earlier, in a choice of delicious colors; plant near your foundation, or as a low shrub border, or in a mixed garden (zones 6-10).

Blue Diddley™ Vitex (Vitex agnus-castus) – blue summer flowers on a 3-6 feet tall compact plant (zones 5-9).

‘Tiny Wine’ ninebark (Physocarpus orbiculatus) – dwarf 3-5 feet ninebark that is smaller than most ninebarks with dark bronze-maroon foliage spring thru fall and white flowers in late spring (Zones 3-7).

Four Tree Conifers Which Should Be Planted More

Posted by Hugh on January 16th, 2022

Nordmann fir (Abies nordmanniana), aka Caucasian fir, is native to the Caucasus Mountains (USDA hardiness zones 4-6). This dense pyramidal conifer grows to 50 feet tall and 20 feet wide and are typically branched to the ground. Their flat dark green shiny needles (up to 1 ¼ inches long) feature two white bands on the underside. Bark is charcoal gray. Their upright cylindrical dark reddish-brown cones measure up to 6 inches long.

Glossy waxy clean needles of Nordman Fir

Best grown in rich, consistently moist, acidic, well-drained soils in full sun to part shade. Best in full sun. Trees grow poorly in heavy clay soils. Trees are native to cool climates, and are not recommended for planting in the hot and humid summer conditions south of USDA Zone 6.

Korean fir (Abies koreana) is a compact, conical to pyramidal evergreen conifer that slowly grows over time to as much as 50 feet tall. Korean fir is for the landscape in cool summer climates. It is native to the mountains of South Korea (USDA hardiness zones 5-7). Branches are densely clad with short but broad needles (to 3/4″ long) that are shiny dark green above and silver beneath. Purple cones (to 3″ long) are produced when the trees are quite young. As is distinctive with the firs, the cones appear upright on the branches.

No serious insect or disease problems. Occasional insect pests include balsam woolly adelgids, bark beetles, spruce budworms, aphids, bagworms and scale. Spider mites may occur in hot conditions. Trees are not tolerant of urban pollutants.

Hiba Arborvitae (Thujopsis dolabrata) is a conical needled evergreen native to Japan in the cypress family. The bright green densely packed needles provide color and winter interest in the garden. Plant in full sun to partial shade in moist, well-drained, neutral to alkaline soils. This tree does not tolerate dry soils. Its mature size is 30-50 feet tall x 15-30 feet wide. It produces tiny thick brown and violet with white wax ovoid seed cones.

*Thujopsis* on East TN State University campus, Johnson City, TN

‘Nana’ – aka dwarf Hiba Arborvitae, is a compact, mound-shaped evergreen shrub with shiny dark green foliage all season long and good form. It is a great evergreen accent for home gardens. The scale-like leaves remain dark green throughout the winter. Flowers or cones are not ornamentally significant.

Golden larch (Pseudolarix amabilis) is native to coastal mountain areas in southeastern China. Pseudolarix (means false larch) is an attractive large specimen tree with excellent needled foliage and fall color. This deciduous conifer tree grows 30-60 feet tall and is slow-growing and broadly-conical with horizontal branching and drooping branchlets. The soft green foliage turns golden yellow in fall before dropping. Needles (to 2.5” long) appear primarily in tuft-like clusters on spur-like short shoots. Cones (2.5 – 3 inches) stand erect reddish brown fruiting cones. Bark on mature trees is fissured and reddish-brown.

Golden larch on North Carolina Arboretum, Asheville, NC

Golden larch thrives in moist, acidic, organically rich loam feet and in full sun. The tree is tolerant of light shade, but intolerant of full shade. Avoid limestone soils. Best sited in a location protected from strong winds. This tree may struggle summer weather is exceptionally hot and humid, but generally outperforms common larch (Larix decidua). It has no serious insect or disease problems.