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

Bloodroot Is Wonderful Woodland Beauty

Posted by Hugh on August 27th, 2015

Bloodroot Emerging Through Leaf Litter In Spring

Bloodroot in Early Spring

Bloodgood (Sanguinaria canadensis) is a long-lived rhizomatous native woodland wildflower. All plant parts exude a bright reddish-orange sap when cut, hence the common name. Indians utilized as a dye and sap is antibacterial, antifungal, and antiviral. Roots are poisonous if ingested (USDA hardiness zone 3 -9).

In very early spring white or pale pink flowers with bright yellow stamens rise 6-10 inches tall. Multiple flower stalks, containing solitary 8-10 petaled blooms, emerge wrapped around by a deeply-scalloped, grayish-green palmate leaf. Single flowers measure 2-inches across and open up in early morning and close at dusk; it lasts only a few days. Scalloped leaves, some 9 inches across, continue to grow in size after flowering is over and remain attractive through early summer when the entire clump dies back (dormant) until late next winter.

Bloodroot is best planted in a humus rich, well-drained soils in part to full shade. It also performs in 1/2 day morning sun, and in dry woodland soils (not initially, but once fully established). In early spring (late winter in the South), large pure white flowers arise atop 6-10 inch tall plants. If site location is ideal, bloodroot self-sows and forms small colonies in woodland shade.

Early fall or late winter are ideal planting times to insure that roots will establish before winter arrives. Potted plants have become more available at garden centers for those who shop for these woodland beauties early spring.

Bloodroot is not troubled by disease or pest problems provided soil is well-drained. Deer, rabbits, moles, voles, and other critters usually leave bloodgood alone. Over the past ten years bloodroot, along with other woodland perennials, have been appearing at local garden centers and specialty native plant emporiums. You should check with Barry Glick at Sunshine Farms in WV or Andrea Sessions at Sunlight Gardens in Andersonville, TN.

Crape Myrtles With Awesome Bark

Posted by Hugh on August 24th, 2015

Light Creamy Bark of ‘Apalachee’

L. ‘Townhouse’ at JC Raulston Arboretum

Trunk Bark of L. fauriei ‘Fantasy’ at JC Raulston in Raleigh, NC

Many cultivars of crape myrtles are hybrids that combine the large, colorful flowers of common crape myrtle (L. indica) with the mildew-resistance and cold hardiness of Japanese crapemyrtle (L. faurei). Many U.S. National Arboretum hybrid releases excel with beautiful year-round ornamental bark.

Among the tree forms are ‘Natchez’ (my favorite), ‘Apalachee’, ‘Lipan’, ‘Muskogee’, and Tuscarora’. Natchez possesses extraordinary cinnamon brown winter bark and is rated among the hardiest in USDA hardiness zone 6.

Some intermediate shrub crape myrtles also exhibit extraordinary bark that is often passed over by landscapers. Gardeners should remove the lower lateral branches to catch a full view of these better forms: ‘Acoma’, ‘Hopi’, ‘Sioux’, and ‘Tonto’. Wait 5 to 6 years to properly evaluate these and other shrub types.

According to Dr. Gary Knox, University of Florida crape myrtle authority, ‘Acoma’ and ‘Lipan’ exhibit near white to creamy brown bark. This trait is desirable in the deep South where white bark birch species (Betula spp.) do not tolerate the intense summer heat and humidity.

Japanese crapemyrtles (L. fauriei) possess some of the best winter bark color. These multi-branched trees grow taller, 40 feet or more in height. On the grounds of the J.C. Raulston Arboretum is a 50 foot tall specimen of ‘Fantasy’ with exquisite cinnamon brown flaking bark. Nearby is another outstanding L. fauriei beauty ‘Townhouse’, with a darker brown bark. White flower spikes in early summer tend to be smaller but very abundant. Japanese crapemyrtles bloom only once a season.

Seven Step Lawn Renovation Program

Posted by Hugh on August 21st, 2015

New fall renovated lawn the following spring

Fall (late August to mid-October) is the “springtime” for lawn care. Most weeds have stopped growing and the cooler weather is a more comfortable time to work outdoors. If your home lawn is in horrible condition, now (not spring) is the best time of the year to take on lawn renovation.

First, here are a few guidelines before you get started. The information is useful for homeowners who reside in temperate areas of the U.S. (USDA hardiness zones 3-7). You will be sowing cool season grasses such as tall fescues, bluegrass, red or chewing fescues, and perennial ryegrasses. Most seed companies package seed blends containing 3-4 varieties. Consult your local Extension office or State Unversity website for additional information.

There are seven basic steps in renovating a lawn:

Apply non-selective herbicide such as glyphosate (Roundup™) that eliminates all vegetation. Follow package directions and use the high rate.
Wait at least seven days for the herbicide to work; it needs to penetrate the foliage and move (translocate) down to the roots to effectively kill plants. Weeds and old lawn grass may still appear green and are essentially killed.
Rototill the soil to 4-5 inch depth.
Broadcast fertilizer and lime (if needed); a soil test prior to starting may be of value, but proceed nonetheless..
Lightly rake to smooth (level) the soil surface, break up large soil clods and remove large debris such as rocks, thatch, twigs, and most fallen tree leaves.
Spread seeds uniformly over the surface and lightly rake the surface a second time to insure soil to seed contact. Previously, you should have measure out the area (length x width) to be seeded, calculated the area square footage, and weigh out amount of seed needed for complete coverage. Do not over apply seeds
Spread clean straw (not hay) over the surface (1-2 bales per 1,000 square feet) to keep moist and hasten seed germination. It also covers the seed to prevent birds from feeding. Additional irrigation to provide grass seedlings water.

Calamint: Tough Reliable Perennial Ground Cover

Posted by Hugh on August 18th, 2015

Variety ‘Marvelette Blue’

C. nepeta ‘Blue Cloud’

Calamint (Calamintha nepeta subsp. nepeta) is low mounding subshrub or perennial native to southern Europe; its primary use is as a low growing ground cover (USDA hardiness zones 4 to 8). It is a member of the Lamiaceae family. Foliage grows only 15-18 inches tall. The subspecies, var. nepeta, is the preferred choice because it produces more flowers per inflorescence.

Calamint tolerates most soil types that are well-drained, and is at its best in full sun with good air circulation.Blooms are white (buds lavender-pink). Airy plumes of small pale blue or white flowers fill their garden spot from June- October. Foliage emits a minty or oregano fragrance when stroked or brushed. Calamint blooms for multiple weeks in the summer and attracts lots of butterflies and bees. Its scent keeps deer away.

Calamint does not spread aggressively around the garden like regular mint. Clumps may be easily divided in early spring. Calamint is popular in Northeast and Midwestern U.S gardens. Calamint tends to languish in warm and humid climates like the southeastern U.S. Snip back plant by one-third in late July to repair its ragged appearance and spur new flowering.

Treat this herbal perennial as short-lived, 3-4 years at most. It is frequently substituted for sometimes iffy baby’s breath (Gypsophila spp.), plus add the aroma of calamint. It is excellent for edging a border along a pathway or plant it in containers. It also makes a great rock garden plant. In the kitchen crushed leaves may be used to flavor favorite pasta dishes.

Purple Heart Tradescantia

Posted by Hugh on August 15th, 2015

‘Purple Heart’ Setcreasia at Ohio State University Gardens

Cobweb spiderwort (T. sillamontana ) at Dallas Arboretum

Purple Heart tradescantia (Setcreasea pallida ‘Purple Heart’), formerly Tradescantia purpurea), is an annual trailing groundcover with purple stems and violet-purple foliage. This flowering vine is primarily grown for its vibrant foliage. Purple Heart is utilized in garden beds, large containers or hanging baskets. By summer’s end individual plants may grow 8-12 inches tall and spreading 16 inches wide.

Purple Heart grows best in full sun to light shade. Its foliage color is darkest in bright sunlight and purple hue diminshes under lower light levels. Colorful leaves may reach 7 inches in length, most often 3-5 inches.

Over the first 4-6 weeks pinch growing tips to encourage better branching and bushier plant habit. Note: pinched cuttings root easily. Small 3-petalled, pale pink flowers appear in late summer. Cut back flowering stems in late summer after blooming to improve plant density. Water frequently and fertilize to establish plant(s). Feed monthly with water soluble fertilize such as Miracle-Gro™, Nature’s Source™ or Schultz™. Plants become very drought tolerant in late summer.

Purple Heart is easily propagated from vegetative cuttings. Stick 3- to 5-inch long tip cuttings in a loose, airy soil mix of medium grade perlite, or gritty sand, or water. Cuttings root quickly, usually within 2-3 weeks. Pot them up to start other container(s) or add to existing garden bed in spring and summer.

Viruses, aphids, spider mites may be occasional problems. Discard virus infected plants immediately.

In mid-autumn frugal gardeners collect cuttings and grow Purple Heart indoors over winter. New cuttings can be started in spring and moved into back to the garden in mid- to late spring.

Others spiderworts to consider:

‘Cobweb’ spiderwort (T. sillamontana) is a wonderful plant collector’s oddity. Native to the mountains of northern Mexico (zones 7b – 10), it remains evergreen in zone 8b and further south. Gray-green leaves and thick stems are covered with white hairs (“cobwebs”). It sports deep pink three petal flowers.

S. pallida ‘Blue Sue’ is a passalong plant sold by Plant Delights Nursery in Raleigh, NC (zones 7b – 10). The 2-inch wide x 5 inch long bluish gray leaves clasp upright dark purple stems; forms an 18 inches tall x 5 feet wide patch over 10 years. Small diurnal lavender flowers appear in late June (NC). Tony Avent recommends it as a groundcover around open branched shrubs, including roses.

Rebloomers Need Your Help

Posted by Hugh on August 12th, 2015

Rebloomer daylily (Hemerocallis ‘Stella D’Oro’)

Iris ‘Immortality’ at NC Arboretum in Asheville, NC

Re-bloomers are specific cultivars that bring on a repeat floral show – two and sometimes three in one season. In my garden re-blooming iris and re-blooming daylilies return for another round of bloom in late summer and fall. Also, deadheading some perennials will cause them to flower again.

You, the gardener, must supply needed soil moisture and nutrition (primarily nitrogen) as these plants should not struggle through an environmentally stressful summer. Plant vigor gets recharged by frequent irrigation and adequate fertilizing. In some situations you may need to monitor and treat disease and insect problems.

As plants finish blooming in “prime time”, remove all spent flower heads to prevent seed formation. For iris prune off old flowers in late May, daylilies in late June and July.

Deadheading: some perennials re-bloom a second and third time when old spent flowers are promptly removed, and plants are properly nurtured. Here are a dozen of easy to re-bloomers: yarrow (Achillea), blanket flowers (Gaillardia x grandiflora), perennial salvia (Salvia x nemorosa), tickseed (Coreopsis verticillata), coneflower (Echinacea purpurea), redhot poker (Kniphofia), gayfeather (Liatris spicata), summer phlox (Phlox paniculata), Shasta daisy (Leucanthemum x superbum), blackeyed Susan (Rudbeckia fulgida), Stokes aster (Stokesia) and speedwell (Veronica spp.).

Note: not all daylily and iris varieties are re-bloomers.

Blackberry Lily

Posted by Hugh on August 9th, 2015

Orange spotted flowers

Blackberry (Belamcanda chinensis) at Yewdell Gardens, Louisville, KY

Blackberry lily (Belamcanda chinensis), aka leopard lily, is native to Central Asia, China, Japan and India (USDA hardiness zones 5-9). It derives its name from clusters of shiny black seeds clearly in view as individual seed capsules split apart as they ripen. Its common name is misleading as it is not a lily, but instead a member of the Iris family (Iridaceae).

The sword-shaped leaves mimic those of gladiolus, also members of the Iris family. The medium green leaves measure up to 10 inches length. Plants grow 2 to 3 feet tall and bloom in mid to late summer (depending where you live). Flowers average 2 inches across, comprised of 6 orange colored petals splashed with red dots. Floral sprays stand on wiry, naked stems, typically 2-3 feet above the flat fan foliage. Heavy rains tend to topple floral stems which do not pick themselves back up.

Two species of blackberry lilies: 1. orange-colored flowers (B. chinensis) are most common; 2. unspotted yellow flowers of B. flabellata (‘Hello Yellow’). Latter species wants for more shade and water. Individual flowers last only a day. Decorative seed capsules are utilized in dried floral arrangements in fall.

Blackberry lilies thrive in average moist well-drained soils and light exposures from partial (4-5 hours) to full day sunlight. Plants may be started from seed or from rhizome divisions. In late summer or fall, before capsules fully open, collect seed and sow in a prepared bed about ½ inch deep. Seedlings emerge in late spring and usually bloom the first year. Blackberry lilies fail planted in poorly drained ground.

Clumps slowly expand via creeping rhizomes and usually not long-lived. They tend to seed-in readily, rarely becoming invasive.

Blackberry lily requires little maintenance. Few potential diseases and pests are troublesome. Iris borers may attack plant rhizomes. Some plant parts are poisonous, if ingested; keep away from young children or pets.

Beware! Yellow Jackets

Posted by Hugh on August 6th, 2015

Paper wasp (photo by Dr. Frank Hale, University of Tennessee Entomologist

Most humans fear and hate yellow jackets. They are actually wasps and important predators of several harmful insects. They’re easily identified by their distinctive markings along their abdomen. They tend to dart about rapidly, in a side-to-side flight pattern. Female yellow jackets are the ones capable of stinging.

Wasps (Vespula spp.) are not bees; they’re brightly colored “cousins” of ground bees. In late summer, while most ground nesting bees are storing up food for the winter, wasps begin to emerge. They had constructed their nests in cool spots such as old rodent burrows, ground holes, under roof eaves, and in mortar cracks between bricks of buildings.

Yellow jackets are social insects. They are not pollinators, but do prey on other pollinating insects and nectar. They scavenge on animal wastes and foods high in protein or sugar. Wasps are highly aggressive and are easily provoked by humans. Favorite places to forage include waste receptacles, soda cans, and picnic foods which they carry back to their nest.

The aggressive behavior of yellow jackets, coupled with their tendency to attack as a group, makes them formidable pests to deal with. When outdoors follow these few wasp avoiding tips. Keep all liquids covered. Don’t swat or crush yellow jackets as this may incite other yellow jackets to attack. If you get too near a nest, backoff slowly. Do not wear bright colored clothes or heavy perfumes.

Call a professional exterminator who has the knowledge, safety clothing, and proper pesticides to find and destroy nests close by your home or patio. Otherwise, leave these mostly beneficial insects alone.

List Of Conifer Reference Gardens In Southeastern U.S.

Posted by Hugh on August 1st, 2015

American Conifer Society Reference Gardens in the Southeastern Region

March 2015

Platycladus orientalis ‘Franky Boy’ at UT Gardens, Knoxville, TN

Pinus wallichiana ‘Zebrinus’ on ETSU Campus in Johnson City, TN

Want to learn about which evergreen and deciduous conifers grow well in your area. The American Conifer Society (ACS) has established a reference garden network across the U.S. If you are developing dwarf conifer collection and want to know their growth rates, visit a reference near you. These public arboretums and botanical gardens are also wonderful vacation destinations.

At this writing eleven (11) gardens have been designated in the Southeastern U.S. Here is the current list:

Gardens of the Big BendUniversity of Florida

155 Research Road

Quincy, Florida

University of Tennessee – JacksonWest TN Research and Education Center Gardens

605 Airways Drive

Jackson, Tennessee

Atlanta Botanical Garden1345 Piedmont Avenue NE

Atlanta, Georgia

University of Tennessee GardensUniversity of Tennessee

2431 Joe Johnson Drive

Knoxville, Tennessee

Lockerly Arboretum1534 Irwinton Road

Milledgeville, Georgia

Al Gardner Memorial Conifer GardenJ. Sargeant Reynolds Community College

1851 Dickinson Road

Goochland, Virginia

Smith Gilbert Gardens2382 Pine Mountain Road NW

Kennesaw, Georgia

Lewis Ginter Botanical Garden1800 Lakeside Avenue

Richmond, Virginia

State Botanical Garden of Georgia2450 S. Milledge Avenue

Athens, Georgia

Norfolk Botanic Garden6700 Azalea Garden Road

Norfolk, Virginia

Hatcher Garden and Woodland Preserve820 John B. White, Sr. Blvd.

Spartanburg, South Carolina

State Arboretum of Virginia400 Blandy Farm Lane

Boyce, Virginia

South Carolina Botanical GardenClemson University

150 Discovery Lane

Clemson, South Carolina

Baker Arboretum4801 Morganton Road

Bowling Green, Kentucky

East Tennessee State University ArboretumEast Tennessee State University

Johnson City, Tennessee

JC Raulston Arboretum4415 Beryl Road

Raleigh, North Carolina

Memphis Botanic Garden750 Cherry Road

Memphis, Tennessee

All About Thistles

Posted by Hugh on July 30th, 2015

Weedy Thistle In Flower Garden

Weedy Thistle flowers

Some weeds are very nasty and on top of my list are the dreadful thistles. Learn the lifecycles of those in your region and the proper method to eliminate them.

Canada thistle (Cirsium arvense) is a perennial species found in many areas of the eastern U.S. Other thistles in my region are bull and Russian thistles that are biennials. Male and female flowers of Canada thistle are found on separate plants, while flowers of other thistles are on the same plant.

Thistles often get their start in abandoned city lots and in uncultivated farm fields. When ready, ripe seed pods may release hundreds of windblown seeds that land in your garden or mine. One Russian thistle (Salsola tragus) plant may produce over 200,000 seeds. In residential areas it usually is an uncaring neighbor or absentee landowner who allows thistles to spread.

If you do not catch them early on, it may take years to get rid of them. Here are four methods of managing thistle infestations:.

Method #1: Never Let Them Seed. Prevent thistles from forming flowers. Cut them off with a mower, hoe, or weed whacker. Frequent mowing prevents mature seed heads from forming. This is particularly effective against biennial species.

Method #2: Dig out the root. If only a few thistle plants, dig up the entire root system which may extend deep into the soil. Broken secondary roots can produce new plants. This method is impractical for large infestations.

Method #3: Herbicides. Apply a non-selective broadleaf herbicide to the entire area. Warning: all vegetation (good and bad) will die. This method is most effective against large infestations.

Apply herbicides when thistles are actively growing, when outdoor temperatures are between 65 and 85º F.
Phenoxy herbicides include these ingredients: MSMA, dicamba, MCPA, and 2,4-D. Tradename products like WeedB-Gone™ and Trimec™, containing 2 or 3 ingredients, work best with multiple applications every 2-3 weeks.
Glyphosate (Roundup™) may be applied to individual thistle plants by swabbing with a paint brush or sponge.

Method #4: Pasture Management. Let horses, goats and sheep to graze on certain thistle species.

Additional notes: Some thistle species are listed as invasive in parts of the U.S.. Canada thistle is a valued nectar food source for larvae (caterpillars) of the Painted Lady butterfly.