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

2022 Perennial Plant Of the Year – Little Bluestem

Posted by Hugh on January 6th, 2022

The Perennial Plant Association (PPA) has named its 2022 Perennial of the Year — Little Bluestem (Schizachrium scoparum) (USDA hardiness zones 3-9). This ornamental grass was chosen because it is suitable for a wide range of growing climates, is low maintenance, and offers multiple-season interest.

Seasonal Transition in Color (Hoffman Nursery, Inc.)

This North American prairie native grass is adaptable to many growing conditions. It is a warm season clumping grass that features blue tones in its summer foliage and a beautiful array of fall colors.

Little bluestem thrives in fall sun to partial shade and in average to poor dry soils. It is also a larval host to some species of butterflies and moths. It grows 3-4 feet high and around 1-2 feet wide. Avoid wet soils. Resistant to deer & rabbit browsing.

PPA board members selected several outstanding cultivars based on plant habit, foliage, and fall color well in several regional areas of the U.S. including: ‘Jazz’, ‘The Blues’, ‘Standing Ovation’, ‘Blue Heaven’, and ‘Carousel’. The cultivars were bred to be bluer in color and more upright in form.

This ornamental perennial warm-season, clumping grass has silvery-blue stems (particularly at the base) and leaves, making it an attractive addition to the landscape.

Little Bluestem is an excellent plant for wildlife. It serves as the larval host for several skipper butterfly species including Dusted Skipper, Cobweb Skipper, Ottoe Skipper, Indian Skipper, Swarthy Skipper, and he Crossline Skipper. Other insects that feed on Little Bluestem include grasshoppers, Prairie Walkingsticks, the leaf-mining beetles, thrips, spittlebugs, and leafhoppers. The seeds of this grass are eaten by songbirds. Little bluestem provides necessary overwintering habitat and food sources for many insects and birds. Female bumble bee queens nest at the base of bunch grasses, like Little Bluestem, where they are protected until they emerge in the spring.

Planting ideas: a lovely grassy texture for the middle of a perennial border, to soften the edge of a garden pond, or wind it through a naturalistic planting.

Information sources: Perennial Plant Association and American Horticulture SocietyW

‘Standing Ovation’ little bluestem

2022 Perennial Plant Of the Year – Little Bluestem

Posted by Hugh on January 3rd, 2022

2022 Perennial Plant Of the Year – Little Bluestem

Summer/Fall Photo credit: Proven Winners

The Perennial Plant Association (PPA) has named its 2022 Perennial of the Year — Little Bluestem (Schizachrium scoparum) (USDA hardiness zones 3-9). This ornamental grass was chosen because it is suitable for a wide range of growing climates, is low maintenance, and offers multiple-season interest.

This North American prairie native grass is highly adaptable to several landscape situations. Little bluestem is a warm season clumping grass that features blue tones in its summer foliage and a beautiful array of fall colors.

Little bluestem thrives in fall sun to partial shade and in average to poor dry soils. It is also a larval host to some species of butterflies and moths. It grows 3-4 feet high and around 1-2 feet wide. Avoid wet soils. Resistant to deer & rabbit browsing.

PPA board members selected several outstanding cultivars based on plant habit, foliage, and fall color well in several regional areas of the U.S. including: ‘Jazz’, ‘The Blues’, ‘Standing Ovation’, ‘Blue Heaven’, and ‘Carousel’. The cultivars were bred to be bluer in color and more upright in form. Select the variety that best performs where you garden.

This ornamental perennial warm-season, clumping grass has silvery-blue stems (particularly at the base) and leaves, making it an attractive addition to the landscape.

Little Bluestem is an excellent plant for wildlife. It serves as the larval host for several skipper butterfly species including the Dusted Skipper, Cobweb Skipper, Ottoe Skipper, Indian Skipper, Swarthy Skipper, and the Crossline Skipper. Other insects that feed on Little Bluestem include grasshoppers, Prairie Walkingsticks, the leaf-mining beetles, thrips, spittlebugs, and leafhoppers. The seeds of this grass are eaten by songbirds. Little bluestem provides necessary overwintering habitat and food sources for many insects and birds. Female bumble bee queens nest at the base of bunch grasses, like Little Bluestem, where they are protected until they emerge in the spring.

Planting ideas: a lovely grassy texture for the middle of a perennial border, to soften the edge of a garden pond, or wind it through a naturalistic planting.

Information sources: Perennial Plant Association and American Horticulture Society

After The Holidays Poinsettia Care

Posted by Hugh on December 26th, 2021

The gift of a poinsettia means you should enjoy the beauty over the next three months or more. Your poinsettia should be warmly wrapped to protect from chilling outdoor temperatures from the garden shop to your home or apartment.

If applicable, carefully unwrap the protective sleeve around your poinsettia to prevent injury to leaves and bracts and set it in a well-lighted winter that receives 4-6 hours of bright light daily. Keep the plant from cold or drafty windows.
Keep poinsettias away from warm radiators, air vents, and open doors. Poinsettias perform at their best in daylight temperatures of 60 to 70°F and night time temperatures around 55°F. High room temperatures will shorten plant life. When possible move the plant to a cooler room at night.
Check the soil (potting media) daily. Be sure to punch holes in pot foil so water will drain into a saucer or gravel tray. Water thoroughly when soil is dry and discard any excess water after 2-3 hours.
Mist the plant with room temperature tap water daily to raise the room humidity.
Start feeding your poinsettia within a month after purchase with any houseplant fertilizer. Or use a water soluble fertilizer such as Miracle-Gro™ or Peters™ @ one teaspoon per gallon of water. Continue to fertilize every 3-4 weeks through March.

True flowers in center surrounded by colorful bracts

With proper care, a poinsettia should continue to be colorful in your home to late February and into March. Snip off the dead or dying once colorful bracts.

Poinsettia Care

Posted by Hugh on December 21st, 2021

Poinsettias (Euphorbia pulcherrima) have become a symbol of Christmas and the winter holidays. Their colorful bracts (most people call them “flowers”) are actually modified leaves. Red remains the most popular color, but select from white, pink, burgundy, marbled, speckled and new “tropical shades”.

Buy a healthy poinsettia! The small yellow flowers in the center of the bracts (called “cyathia”) are fresh and not dried out or turning brown. If the cyathia have dried out, do not purchase. Once the flowers start to age, the colorful bracts soon decline. In the room do not set the plant close by a heat source or cold window. Pick up the pot — if it feels light, then water it.

Inside the typical home or apartment, poinsettia only needs water every 5-7 days. Before watering your poinsettia, remove the decorative pot covers or foil that most poinsettia varieties are packaged in. The pot cover can hold too much water, something a poinsettia does not like. Punch holes in the bottom of the covers and set on a saucer. Do not leave your plant pot(s) sitting in water over 3 hours as it may injure the roots.

Place your poinsettia near a sunny south- or east- facing window of your house or apartment. Room temperatures should be between 65 – 75 °F. Poinsettias thrive in a well-drained soil-less media (potting mix).

Feed the plant every 2-3 weeks with a water-soluble garden or house plant fertilizer @ one-half the rate on the package directions. Your poinsettia should continue to look pretty into the early days of spring.

Poinsettia Tree at Atlanta Botanical Garden

Poinsettia plants are NOT poisonous – The white sap is not toxic to humans, dogs and cats. Some people and pets may be sensitive to the plant’s sap which may cause a skin irritation. Some veterinary medicine websites state that poinsettias can be mildly toxic to dogs and cats and can cause vomiting, drooling, and, rarely, diarrhea.

Bird Friendly Trees And Shrubs

Posted by Hugh on December 16th, 2021

Birds visit trees, shrubs, and vines for five things: fruits (berries), sweet nectar (flowers), insects (particularly caterpillars), nuts and seeds, and shelter. This list is a compilation from the North Carolina and Tennessee chapters of the Audubon Society of ornamental plants common in the Southern Appalachian region.

Trees and Shrubs (26)

Maples (Acer spp.)

Downy Serviceberry (Amelanchier arborea)

River Birch (Betula nigra)

Beautyberry (Callicarpa americana)

Hickories (Carya spp.)

Dogwood (Cornus florida)

New Jersey Tea (Ceanothus americanus)

Hawthorns (Crataegus spp.)

Winterberry (Ilex verticillata)

Virginia Sweetspire (Itea virginica)

Eastern Red Cedar (Juniperus virginiana)

Spicebush (Lindera benzoin)

Sweetbay Magnolia (Magnolia virginiana)

Crabapples (Malus spp.)

Blackgum (Nyssa sylvatica)

Pines (Pinus spp.)

Wild Plum (Prunus americana)

Cherries (Prunus spp.)

Sweet Azalea (Rhododendron arborescens) – at higher elevations

Pinxterﬂower (Rhododendron periclymenoides)

Oaks (Quercus spp.)

Willows (Salix spp.)

Elderberry (Sambucus canadensis)

Sassafras (Sassafras albidum)

Arrowwood Viburnum (Viburnum dentatum)

Smooth Witherod (Viburnum nudum)

Woody Vines (3)

Trumpet-creeper (Campsis radicans)

Cross-vine (Bignonia capreolata)

Coral honeysuckle (Lonicera sempervirens)

Raked Leaves Improve Garden Soil

Posted by Hugh on December 9th, 2021

Don’t rake and send fallen leaves to urban landfills. In a recent poll, nearly one-third of weekly disposable materials are composed of yard waste, newspapers, and food waste. Many of your neighbors are sending bags of “nutrient gold” to landfills. Improve your gardening skills and save money.

Adding fallen leaves back into the garden is one of the most ecofriendly solutions that gardeners can adopt. Fallen leaves are free mulch. They’re gathered by raking, blowing, or a lawnmower with a bag attachment. A mower with a bag shreds the leaves – eventually creating a uniform leaf mold (mulch). The final product also creates a tidier look in your garden.

Put shredded leaves around the base of trees and shrubs, pile them up several inches over annual flowers or vegetable beds. A loose layer of shredded leaves can be about 3 to 5 inches thick that aids in controlling weeds. Alternatively, if you prefer the uniform darken look of store-bought mulches, start with free freshly fallen leaves as a base layer, and add a topping of purchased mulch. Over winter the fallen leaves and mulch break down and supply nutrients to the soil.

Get ahead of spring mulching chores by adding 2-3 additional inches of chopped leaves each season. October thru December is the interval when most deciduous and evergreen trees lose their leaves. Some oak and beech trees wait until late winter to lose theirs, giving rise to another wave of free mulch creation.

Mulch (composed yard waste) available at Local Garden Center

Fall leaf collecting and adding them to your compost pile greatly increases the quantity of ready for use soil conditioner in the spring. This will reduce gardening costs (think less fertilizer and lime) and improve the health of your garden plants. Oak leaves and pine needles tend to create an acidic mulch which is ideal around acid-loving azaleas, rhododendrons, mountain laurels, gardenias, hollies, to list a few.

Leaf compost provides all the nutrients that winter/early spring wildflowers such as trilliums, Virginia bluebells, winter flowering aconites, snowdrops, hardy cyclamens, and so many others need.

Empress Tree (Paulownia)

Posted by Hugh on November 26th, 2021

Empress tree (Paulownia tomentosa) is a fast-growing shade tree, in some years adding 4-5 feet of new growth, eventually to reach heights of 40-50 feet and width of 20-30 feet in less than 20 years.

Paulownia Planting at Longwood Gardens in Kennett Square, PA

In the first 3-4 years, juvenile trees develop enormous size leaves. Once trees start producing flowers (adult stage), leaves are alot smaller, although still bigger that most oaks or maples. Some gardeners create the tropical foliage appearance by cutting back young trees every 1-3 years to maintain enormous sized leaves. By doing so, they avoid flower formation which results in seeds and lots more sapling trees in the neighborhood.

Showy upright clusters of lavender flowers measure 14 or more inches across and are beautiful, although most are hidden within the bulky spring foliage. The large, velvety looking leaves resemble catalpa tree leaves.

Individual 1.5-2 inch long tube-like blooms are vanilla scented and edible. Woody brown seed capsules follow in the fall; the capsules split open to reveal winged seeds.

Paulownias are not recommended for landscape planting as they are considered short-living weedy trees. They survive in a range of soils including low fertility and high acidity sites, and either in partial to full sun. As a shade tree, it forms a wide canopy of dense shade, creating too much competition for most ground covers to survive. Paulownia is resistant to most urban air pollutants.

Insects, Diseases, and Other Plant Problems: Frost damage to early spring flower buds is possible. Plant experts rate paulownia trees as weedy, messy, weak wood and invasive species. Seed heads form in summer and the ripened seed fall in late October. According to University of Tennessee forestry experts: “some 90% of paulownia seeds are not viable, yet many states list the tree as invasive”.

In Asia, paulownia wood is manufactured into paper, veneer, hand-carvings, clogs, musical instruments, furniture, rice pots, water pails, bowls, and spoons. Some U.S. growers export the wood to Asia. It has also some medicinal uses in Asia.

Prepare For Storm Damage

Posted by Hugh on November 22nd, 2021

A snow/ ice storm is both a beautiful and horrific scene in a landscape. Costly tree/shrub breakage, downed power lines, and subsequent utility shutoffs may be staggering results. Don’t feel powerless! Prepare and take action. During the storm, do nothing / “hands off”. Working near an active electrical line is deadly.

After the storm you should immediately assess the landscape damage. Contact your insurance agent and hire an ISA* certified professional arborist to fit your property into his/her schedule. After a storm, arborists are likely much too busy with emergency callers.

Inspect your trees BEFORE storms are predicted. First on your list should be those large trees not pruned in many years. Old trees are likely to shed diseased, pest ridden, and structurally weak limbs. Notorously weak wooded deciduous trees are silver maple (Acer saccharinum), sycamore or planetree (Platanus spp.), Bradford pear (Pyrus calleryana), poplars (Populus spp.), and willows (Salix spp.). They generally drop small twigs to large branches all the time. Large evergreens like white pine (Pinus strobus), Southern magnolia (Magnolia grandiflora) and leyland cypress (Cupressocyparis x leylandii) frequently loses branches and twigs during high winds and ice buildup.

Ironically, the trees suffering the worse damage are those topped by “Landscape Pros”, neighbors, and utility companies. The re-growths on topped trees are very weak and snap off when the snow and ice loads reach a critical mass. Properly pruned trees ride out most ice storms. Take care of your trees and trees will continue to beautify and cool.

2020 Evaluation of Russian Sages By CBG

Posted by Hugh on November 16th, 2021

Russian Sage (*Perovskia atriplicifolia*)

Russian sage (Perovskia spp.) is a popular garden and landscape plant valued for its lavender-blue flowers and long bloom period. Leaves are silvery green leaves. Long cultivated as an herbaceous perennial, Russian sage is technically a subshrub, a plant with a woody base that produces herbaceous stems. Perovskia spp. has recently renamed Salvia yangii and is a member of the mint family (Lamiaceae). Leaves and stems are pungently aromatic when crushed. Despite of its common name, Russian sage is not native to Russia, instead native to southwestern and central Asia.

Chicago Botanic Garden (CBG) (USDA Hardiness Zone 5b, AHS Plant Heat-Zone 5) recently completed an eight-year comparative trial of Russian sages in October 2020. Five cultivars earned five-star excellent ratings for their superior floral displays and consistently strong habits: Blue Spritzer, ‘Blue Jean Baby’, ‘Blue Steel’, ‘Little Lace’, and ‘Denim ‘n Lace’.

Russian sages are prized for their fuzzy lavender-blue flowers and silvery-filigreed foliage on upright, sturdy stems from mid-July to mid-October.
Most new introductions are chosen for their shorter, more compact habits. Bees and other insects were constant visitors during the long bloom period. No diseases or pests trouble this low maintenance perennial. Foliar chlorosis was a minor issue observed on all varieties, observed in high pH soils.

‘Blue Spritzer’ (‘Balperobritz’) has a bushy, vase-shaped habit—30 inches tall and 36 inches wide along with lighter lavender-blue flowers on airy spires and purple calyces. Blue Spritzer featured egg-shaped, silvery green leaves with entire margins; some leaves are occasionally serrated.

‘Blue Jean Baby’ is a compact bushy variety just under 30 inches tall and 32 inches wide. From early July to October, a profusion of lavender-blue and purple flowers; sage green, deeply dissected leaves.

‘Blue Steel’ is a seed cultivar that compared favorably to vegetative cultivars; 32 inches tall and 34 inches wide; airy dark lavender-blue flowers from July into mid-October; ovate, bluntly serrated green leaves with wavy margins and citrus-scented.

Little Lace (‘Novaperlac’) provided an impressive flower show from early July into early October; compact bushy plants—32 inches tall and 38 inches wide; deeply incised gray-green leaves and airy lavender-blue flowers.

‘Denim ’n Lace’ flaunt densely clustered, upright sky blue flower panicles from mid-July to mid-October; above high pollinator activity; 33 inches height and 48 inches width.

Read the entire research report on the Chicago Botanical Garden website.

Enormous Leaves On Sapling Trees

Posted by Hugh on November 11th, 2021

Some fast-growing trees like Royal Empress tree (Paulownia tomentosum) smoketree (Cotinus coggygria), and basswood linden (Tilia americana). There are lots more arboreal candidates. Keep the young tree saplings vegetative by practicing “Renewal Pruning”.

To create an accent tree, single or multi-stemmed, wait until the plant has been in the ground for a few years, then begin to limb up the shrub. Select one to three stems that will become the dominant 1 or more trunks of your small tree and remove all other branches. Continue to shape this way until you arrive at the desired look. Again, snip off lower and interior branches that may develop.

Several Cotinus cultivars produce colorful seasonal foliage such as: ‘Royal Purple’ has burgundy foliage that changes to brilliant red in fall; ‘Grace’ struts huge, maroon leaves and deep salmon pink fall color; ‘Golden Spirit’ (Ancot) has chartreuse leaves that turn yellow in autumn.

If your goal is colorful foliage, cut the stems back garden in winter to 6 to 8 inches. The following spring enormous size leaves develop on vigorous growth from the ground. This is classified as hard pruning or renovation pruning and can be done every year. Just cutback last year’s woody shoots and start over. Fertilize annually and irrigate during long summer dry periods.