Tips On Growing Sourwood Trees

Awesome Fall Color Of Sourwood In Western North Carolina


Sourwood (Oxydendrum arboreum) is one of the most beautiful flowering trees in the U.S. Trying to establish one in your landscape can prove quite challenging. In the wild sourwood grows in shallow soils on steep craggy or rocky ground. Dry ground seems to be the rule. It grows either multi-stemmed (shrub-like) to 20-30 feet or tree form to 35-40 feet and half that in width.

Sourwood is a pioneering species. Tiny dehiscent seeds are dispersed into the wind and blown like dust over many acres of land. Tens of thousands of seedlings germinate each spring on new ground that may have been previously clear cut for reclamation. If available, supply water intermittently over dry periods the first two summers. Established trees tend to better cope with heat and dry soils.

For a home gardener the challenge seems to be getting one established. Site them in the type of soil and environmental conditions which rhododendrons and mountain laurels enjoy. They prefer a loose, gravelly, acidic soil containing some organic matter and excellent drainage. A newly-planted sourwood prioritizes by establishing its root system first.

Purchase primarily nursery container-grown trees, if you can find them. Plant in well-drained soil and prune the new tree or shrub back to 6-12 inches from the ground in early spring. Essentially, you are starting over with 100% root system and 10-15% top (shoot). What comes up is your new tree, more vigorous than one not pruned.

In nature sourwood seem to prefer the eastern facing slope of the woodland where they receive midday sun. Young transplants respond to fertilizing; older well-established trees do not. Sourwood requires little pruning and has few serious insect or disease problems.

Prune to Rejuvenate Old Foundation Shrubs

Old fashion Nandina in Desperate Need of Pruning

Eventually, old foundation shrubs around your home grow too tall and spindly and need to be started over. Rather than digging them up, most deciduous and a few broadleaf shrubs respond to rejuvenation pruning. Sorry, evergreen conifers do not respond to this form of pruning.

Get started with a sharp pair of pruning loppers or tree saw for the large cuts and hand pruners for smaller cuts. February and March are good times to rejuvenate old shrubs.

Before getting started with pruning, understand what you’re about to do. You desire a low, dense-growing multi-stemmed shrub. Pruning reduces shrub size and redirects new growth from surface roots and above-ground shoots. 

Remove the tallest and thickest woody shoots to the ground. Cutback pencil-thick shoots to 12-18 inches from the ground. Remove all weak or dead stems flush to the ground.

After pruning, feed the shrubs, applying 1-2 handfuls of 10-10-10 (or equivalent) granular fertilizer in a 1-2 feet wide circle around each shrub. Disperse no fertilizer closer than 6 inches from the shrub base.

Rejuvenated shrubs should vigorously re-grow in the spring and summer months. Summer flowering shrubs likely will not bloom the first year after pruning.

Caveat: pruned shrubs must be in good health before attempting to rejuvenate them. If they have not re-grown by late May, a trip to the garden center to purchase new plants is in order.

Give Edgeworthia A Try In Your Winter Garden

Paperbush (Edgeworthia) in Bloom in mid-March Garden


To begin, I must thank South Carolina nurseryman, Mr. Ted Stephens, who gifted me a Chinese paperbush (Edgeworthia chrysantha) 12 years ago. Most plant authorities rate its winter hardiness to USDA zones 7 and 8, but no one told this to my edgeworthia in zone 6-b. People who see it blooming in my early March garden like it and ask what it is. While paperbush may struggle its first winter before becoming fully established, it never disappoints.

Paperbush will become a joy waiting for you on a cool March day. Six months later (mid-autumn), its unique nodding floral buds are clearly visible on branch tips. Paperbush is a close botanical relative of the daphnes. Up close, the small tubular flowers are very fragrant!

Flowers are light yellow on the inside and white on the outside. Over the years roots may sucker new plants, eventually developing into a small plant colony. If your plant reaches suckering stage, congratulations, it is happy in your garden.

Paperbush is a multi-stemmed shrub, and new shoots are covered with reddish brown hairs. The 4-5 feet tall and wide plants have attractive greenish blue summer foliage.

Paperbush should be planted in partial shade away from high winds and direct summer sun. Plant in compost-rich, well-drained, acidic soil. Fertilize in early spring with slow-release Hollytone™, Nutricote™, or an equivalent product.

According to Plant Delights Nursery in Raleigh, NC, the species E. chrysantha is more winter-hardy (below 0 °F) than E. papyrifera. Paperbush is a collector’s plant and is sold on-line by e-commerce nurseries.

New cultivars abound including ‘Red Dragon’ with pale reddish-lipped tubular florets and ‘Snow Cream’ with pale yellow florets.

‘Thunderhead’ Pine

'Thunderhead' Japanese black pine at UT Gardens, Knoxville, TN

‘Thunderhead’ Japanese black pine at UT Gardens, Knoxville, TN

Thunderhead Japanese Black Pine (Pinus thunbergii ‘Thunderhead’) is a dwarf compact form of Japanese black pine (USDA hardiness zones 5b-8). Expect this slow-growing conifer to reach 5 feet high and 4 feet wide in 10 years. Whereas Japanese black pine grows 60 to 80 feet tall, Thunderhead matures to 20 to 25 feet in height and 15-20 feet in spread after many years.

By mid-winter its long silvery buds are clearly visible; they slowly elongate over the winter months. The white candles unfurl in mid-spring. This 2-needle pine has dark green needles which average 3 to 4 inches in length and are densely clustered together.

Japanese black pine grows best in well-drained soil and in full sun. Once established two years, Thunderhead pine exhibits exceptional drought tolerance.

Japanese black pine is a favorite among bonsai enthusiasts and those who sculpt topiaries. In a small garden you’ll enjoy Thunderhead’s natural pyramidal form. No two plants ever look alike if they’re left unpruned.

Japanese black pine thrives along coastal areas with hot dry temperatures and salt spray. Coastal areas of North and South Carolina and Georgia have planted this pine species extensively for sand dune stabilization around beach areas. Along roadsides it stands up to winter de-icing salts.

Hepaticas Bloom In The Early Spring Garden

Hepaticas blooming at Atlanta Botanical Gardens


Hepatica (Hepatica spp), from the Latin word “Hepaticus” meaning liver, is sometimes cataloged as “Liverleaf” or “Liverwort” (USDA hardiness zones 4 – 9). It is one of the first spring wildflowers to bloom (March-April). H. americana, native to the eastern U.S. and Canada, bear showy white flowers that are sometimes tinged pink or blue. H. acutifolia, a Midwest species, features white, pink, lavender, and blue flowered forms. Hepaticas are often purchased from native plant nurseries on-line.

Hepaticas are exceptionally long flowering, long-lived and easy to grow. Individual ½ – 1 inch wide flowers arise before the new foliage unfolds. The anemone-like flowers stand atop hairy 4-8 inch tall stalks. Each flower has 6-10 petal-like sepals subtended by three bracts.

At the start hepaticas tend to grow off slowly. They grow 3 to 6 inches tall in a rich woodsy soil that is well-drained and in a part shade (early morning sunlight) garden spot. In the southern U.S. they grown under heavier shade. Hepaticas thrive in moist and struggle in dry soils. Under optimal growing conditions, vigorous plants will self-seed and form naturalized colonies, each greater than one square foot in area and will bloom prolifically.

The large three rounded lobes (tri-lobed) basal leaves have a dull or matte finish over their upper surface. Late in the summer leaves turn dry and leathery. In southerly climates the old foliage persists all winter and new flowers emerge through the leafy debris.

2014 Plant Winners Announced

Echinacea (coneflower) named 2014 Perennial of the Year by National Gardeners Bureau

Echinacea (coneflower) named 2014 Perennial of the Year by National Gardeners Bureau

Petunia Declared Annual of 2014 by NGB

Petunia Declared Annual of 2014 by NGB


At the start of each year the Motion Picture Industry awards their Golden Globes and Oscars. The Music Industry has the Grammys. Gardening associations also announce the award-winning plants.

The National Garden Bureau (NGB) has declared 2014 Year of the Echinacea (coneflower) in the perennial category. NGB declared the mighty cucumber as Vegetable of The Year, and Petunia as Annual of The Year. Their primary purpose is to create buzz among gardeners about these great plants. NGB’s website there is lots of reliable cultural information about these plants and other plants. It helps growers and garden centers to increase plant sales.

All American Selections (AAS) trials annuals and vegetables varieties across the United States annually. AAS awards now includes perennials and the 2014 perennial picks are: Gaura Sparkle White (Bedding Plant Award) and Penstemon Arabesque Red F1 (Flower Award).

Perennial Plant Association (PPA) selected Northwind switchgrass (Panicum virgatum ‘Northwind’) as the 2014 Perennial Plant of the Year. This native grass grows 5 to 6 feet tall with a narrow upright form and steel green foliage.

2014 Hosta of the Year (American Hosta Society) – Hosta ‘Abiqua Drinking Gourd’ features deeply cupped, thick textured leaves. The rich blue-green leaves are large size, heavily corrugated.

2013 Stout Silver Medal Winner (American Hemerocallis Society) – ‘Heavenly Angel Ice’ is a re-blooming daylily with 8-inch wide flowers/white petals and green-yellow throat. Flower scapes grow 36 inches high. Note: 2014 winner is designated late in 2014.

2014 Dykes Medal Winner (America Iris Society) – Iris ‘That’s All Folks’ is a tall bearded iris with giant brilliant golden flowers with ruffled and laced edge petals.

2014 Ivy of the Year (American Ivy Society) – Hedera helix ‘Teneriffe’ – an old ivy variety with yellow-cream colored variegated, small-leafed ivy.

Christmas Ferns Are Easy To Grow

Christmas ferns at Cades Cove in the Smoky Mtns, Tennessee

Christmas ferns at Cades Cove in the Smoky Mtns, Tennessee


On a woodland hike in the eastern U.S., lush colonies of evergreen Christmas fern (Polystichum acrostichoides) flourish along the moist slopes (USDA hardiness zones 3 to 8). This native perennial fern favors either a deep or light shade environment. A vigorous clump may grow 18 – 24 inches in height and width. Set new plants in a garden 12 – 18 inches apart.

New spring growth has a silvery cast, becoming dark green in summer. The advance of winter gradually takes its toll on the foliage. A gardener may opt to remove the old yellowed or dried fronds in late winter before the new silver green fiddleheads emerge. Fertile fronds have smaller upper leaflets (pinnae) which produce spores on their lower surface.

Christmas fern prefers humus-rich woodland soil with 5.0 – 7.0 pH range. Feeding plants is rarely necessary if the woodland environment is optimum. Decaying mulch around the ferns usually provides adequate nutrition. Fronds stand dark green and tall after a deep soaking summer rain.

As a ground cover Christmas fern tolerates little to no foot traffic. Avoid planting on a poorly drained soil which may lead to crown rot disease.

Whether growing in the wild or in a garden, Christmas fern co-habitats with dozens of woodland plant favorites including celandine poppy, Solomon’s seal, Jack-in-the-pulpit (Arisaema triphyllum), camassia, woodland asters, wild ginger, among others. Its dark green evergreen foliage is utilized for home decorations during the jolly holiday season.

Urban Trees Reap Cleaner Air

Urban Tree Planting In Downtown Charlotte, NC

Urban Tree Planting In Downtown Charlotte, NC


U.S. Forest Service scientists with the Center for Urban Forest Research report that planting and nurturing street trees in Indianapolis, IN returned 500 percent in benefits from storm water reduction, energy conservation, cleaner air and increased property values.

The researchers evaluated more than 117,000 trees the city’s Parks and Recreation Forestry Section manages. It found that every $1 spent brought a $6.09 return. Each tree annually removed 1.5 pounds of air pollutants, valued at $2 per tree or $212,000.

“Indianapolis’ urban forest is uniquely diverse, with only one of over 170 species representing slightly more than 10 percent of the total tree population,” said Greg McPherson, Center for Urban Forest Research director. Species diversity is important because the urban forest is at less risk of catastrophic losses from diseases or pests.”

Scientists found Indianapolis trees annually intercept 318.9 million gallons of rainfall, an estimated worth $1.98 million or $17 per tree per year. Trees also annually cut electricity use by more than 6,447 megawatt hours, worth $432,000. They reduce natural gas use by more than 150,000 therms, yielding annual benefits of $165,000 or $5 per tree.

Total annual tree benefits varied by species and size. For example, silver maples (Acer saccharinum), representing the largest species planted, produced the greatest benefit at $60 per tree, but they also were the most expensive to manage. Several were nearing the end of their productive lives and required removal or intensive care.

Source: U.S. Forest Service, Center for Urban Forest Research, January 2014.

Winter Sap Bleeding From Trees Not Harmful

Icicle Off Poor Pruning Cut in Fall

Icicle Off Poor Pruning Cut in Fall

Winter can be a cruel period for trees. Day-night temperatures may wildly fluctuate and drying winds tend to injure tender buds. Maples (Acer spp.), flowering dogwoods (Cornus florida), birches (Betula spp.), yellowwoods (Cladrastis kentukea), walnuts (Juglans spp.) and elms (Ulmus spp.) are “bleeders”. The sap pressure inside branches is highest during the winter months.

If any tree jeopardizes a house, property, utility lines, and human safety, it should be pruned no matter the time of year. The bleeding sap phenomena is over-rated. Winter-pruned bleeder trees will not die. If it humanly bothers you, prune these “bleeder” species in the summer when sap pressure is lowest.

Leaky sap may drip on pedestrians, cars, and walkways resulting in stains on trunk bark and sidewalks. Puddles on walkways may freeze and create slippery pavement.

Bleeding or sap loss will eventually stop on its own. Quickly, the pruning wound cuts have internally sealed off and the healing process started.

Spraying paint (wound dressing) does not help. Many times the sap flow is so plentiful as to wash the wound paint off. You may want to irrigate the tree during dry spells to speed wound healing.

If you’re seeking advice about pruning large shade trees, consult a certified arborist first. The International Society of Arboriculture (ISA) website should list one or more in your area.

Soil Sampling Is Good Insurance

Soil sampling is good gardening insurance!

Soil sampling is good gardening insurance!

Do you know what your soil needs to grow a great lawn, flower, or vegetable garden? If you haven’t analyzed the soil in the past five years, get it done in any season. Most gardeners do it in late winter when university, state, and private soil labs are busiest.

The local Extension office or a garden center can supply you with one or more sample kits with instructions and forms detailing how to sample. Mail the soil, form, and money to the soil lab.

If soil conditions have drastically changed because great amounts of organic matter, topsoil, etc. were added or accidentally spilled fertilizer or another chemical, retest your soil. Do you have a special problem area? Separately test this spot and explain the problem. Photos are optional.

In early fall, before you’re ready to tackle a major fescue/bluegrass lawn renovation, soil test before the work starts. Be sure to mark on the form that you want recommendations for a lawn. With a lab results in hand, they detail how many pounds of fertilizer to apply. If lime or sulfur to raise or lower the soil pH, that is included on your report.

If you’re planting acid-loving plants such as azaleas, blueberries or mountain laurels (Kalmia app.), inform the soil lab; they will estimate when and how much sulfur to apply. Planning a home fruit orchard (apples, peaches, plums, grapes, brambles), tell the lab intended use of the land.

Basic sampling instructions: using a trowel, take 8-10 random samples of topsoil from various parts of your yard. Dig only 5-6 inches deep. Mix all together thoroughly in a bucket. Place a small amount of the soil mixture in a paper (not plastic) bag or box, enough to fill a small baby food jar. Do not ship wet soil.