Sunday, March 28, 2010

Golden Hakonegrass Lights Up The Shade Garden

Light up dark areas in your shade garden with this wonderful golden ornamental grass from Japan. Golden hakonegrass (Hakonechloa macra 'Aureola') grows 12-18 inches tall and 18-24 inches wide with a mounding cascading form.
Very thin green stripes (veins) flow the length of the ½ inch wide golden leaf blade. The cool nights in the fall adds a pink to reddish tinge to the blades before all dies back for a long winter’s nap. Tiny, relatively inconspicuous, floral spikes appear for a short time in late summer.
Golden hakone prospers in moist humus-rich, well-drained soil. Contrarily, it grows poorly in compact heavy clay soils. Hakone prefers a partially shaded garden spot, receiving 2 hours of early morning or 1/2 day of dappled sunlight.
Golden hakone grows slowly, spreading by stolons and rarely trespasses spaces occupied by neighboring hosta, astilbe, heuchera and other companions in the shade garden.
Golden hakone is rarely bothered by disease or insect pests and is not troubled by deer. 'Aureola' hakone grass was selected the Perennial Plant of the Year in 2009.

Saturday, March 27, 2010

Viburnums for Privacy Screening

photo: the clean summer foliage of 'Allegheny' viburnum
Must you plant an evergreen hedge when a semi-evergreen flowering shrub is fine for the task?
Leatherleaf viburnum hybrid cultivars 'Allegheny' and 'Willowwood' are 60% evergreen, dropping their foliage very late in autumn in U.S.D.A. zones 6 and 7-a. 'Willowwood is preferred over 'Allegheny' in areas of zone 6 and 7 where powdery mildew disease may be a problem.

Prague viburnum (Viburnum pragense) is the only "true" evergreen viburnum. It possesses lustrous dark green foliage year-round and grows to 9-10 feet. Its height is tall enough to become a beautiful privacy screen and noise barrier from the neighbors and traffic.

All three viburnums are excellent growers. They have a distinct advantage over most conifer species used in privacy screening. These lovely viburnums flower in late spring and early summer, something the conifers don't offer.

Friday, March 26, 2010

When to Prune Flowering Shrubs

photo: Weigela 'Wine and Roses'

Prune spring flowering shrubs and trees immediately within one month after flowering. These plants set their flower buds on last summer's woody shoots. Common shrub examples include forsythia, lilac, weigela, mockorange, loropetalum, honeysuckle, and many viburnum species.
Summer-flowering plants set their flower buds on spring wood (this year) when they bloom. They are pruned in late summer into early fall (after flowering). You may also wait until late winter into early spring before shrubs leaf out. Some examples are crape myrtles, althea (Rose of Sharon), chaste tree (vitex) and most hydrangeas.
Other tips: remove all dead, diseased, and damaged wood anytime of year. If scale insects are present, remove the worst infested shoots, reducing the need for pesticide spraying.
Prune off weak spindly wood if it takes away from the desired shape or form of the shrub.
Finally, you can reduce shrub height by pruning off the branch(es) at point of origin, near the ground around the base of the shrub.

Sunday, March 21, 2010

Lo and Behold 'Blue Chip' Buddleia is a Winner

photo taken at JC Raulston Arboretum in June 2009
Lo & Behold® ‘Blue Chip’ is a very dwarf butterfly bush (buddleia) for the summer garden. Take advantage of its compact 3 x 4 foot height and width by planting it in the garden or in a container on a sunny patio deck or patio by itself . In large containers mix in shorter growing summer annuals such as trailing petunia, scaevola or alternanthera.

Lo & Behold® ‘Blue Chip’ maintains its clean growing habit all season long. Gardeners with limited space can attract butterflies and hummingbirds to their garden with this colorful buddleia. It produces loads of fragrant blue flowers which bloom continuously. It thrives in the summer heat and humidity and the foliage stays blemish-free.

'Blue Chip' is non-invasive. It's self-cleaning and will bloom from mid-summer to frost without deadheading. Each proceeding spring, you won’t need to drastically prune 'Blue Chip' as you would the larger growing buddleia varieties. Plants are deer resistant and drought tolerant.
‘Blue Chip’ was still blooming in my Southern Appalachian garden in late October .

Wednesday, March 17, 2010

Best of Perennial Veronicas for Gardens


photo: Veronica spicata 'Royal Candles' (not evaluated in CBG study)

Chicago Botanic Garden (CBG) has published the results of a 10-year study of speedwells (Veronica and Veronicastrum) in its 33rd issue of Plant Evaluation Notes, “A Comparative Study of Veronica and Veronicastrum".

Seven speedwells received good-excellent ratings for their overall performance, including Veronica ‘Fairytale’, V. ‘Giles Van Hees’, V. austriaca ‘Ionian Skies’, V. longifolia ‘Blue John’, V. spicata ‘Baby Doll’, V. spicata ‘Ulster Blue Dwarf’, and V. wormskjoldii. These top-rated speedwells exhibited strong growing and excellent flower production throughout the evaluation period. The lack of any serious pest or disease problems, along with good winter survivability, contributed to their high ratings. Additionally, 18 taxa received four-star good ratings for similarly strong performances.


Speedwells are generally easy to grow and prefer sunny locations in moist, well-drained soils. Plants grown in less light will not bloom as profusely and may become lax or open in habit. Crown loss or plant death may occur in wet soil conditions in winter.


Many speedwells require a midsummer shearing after the first bloom to promote a healthy new basal foliage and to encourage late summer flowering. Deadheading of spent blooms produces many new bloom spikes later in the summer. By selecting the best cultivar(s), you may avoid potential foliar diseases, including powdery mildew, downy mildew, leaf spots, and foliar rust.


Generally, plant disease pressure is more severe here in the Southern Appalachian Region than in the Midwest. Read the entire 8 page CBG report (Issue 33, 2010) authored by Richard G. Hawke.

Monday, March 15, 2010

Growing Spuria Iris Worth The Challenge












photos courtesy of Iris City Gardens

Jimmy Turner, Dallas Arboretum horticultural guru, gave me this idea. Growing spuria iris in the Southern Appalachian region can be quite challenging. Hardy to USDA zone 5, spurias are dormant (asleep) during our usually hot, dry summers. A wet summer is a real “downer” for spurias.
Spuria irises bloom two weeks after the popular tall beard iris. They grow and flower best under full sun. Spurias are not choosy about soil type and pH. Bloom stalks can reach 4+ feet in height in a good garden soil.
Foliage dries up in the heat of summer, very natural for spuria iris. Gardeners should not attempt to revive them with irrigation. Autumn showers revive plants. Once growth re-starts, plants hate to dry out.
Spurias need one year to become established. Space plants at least 3 feet apart. Divide them every 5 years. Natural rainfall in our region is usually plentiful. The easiest way to kill spurias is to mulch and overwater them.
You may purchase spurias from several mail order nurseries or local nurseries which specialize in iris. Personal shopping emporiums include Iris City Gardens in Nashville, TN and Heritage Gardens in Greeneville, TN.

Sunday, March 14, 2010

Time to Plant Early Vegetables

Photo credited to University of Illinois Extension

Spring weather seems to have finally arrived here in the Southern Appalachian region. While the weather has changed for the better. Night time temps have remained above 30° F over the past 8-9 days. Spring frosts in the morning are common in this region into early May. More snow showers will likely occur, so it is wise not to stow away the snow shovel just yet.

St. Patrick's Day (March 17) signals the traditional start for planting early veggies, called the cole crops, within USDA zones 6-b to 7a. Night temps in the mid-20's are unlikely to injure these cool season vegetables.

Why the early start? Well-rooted young plants in March better cope with the warm 70°F days ahead in April and May. Poorly established vegetables like cabbage, broccoli and cauliflower get "heat stroke" on hot days and likely will bolt (go to seed).

Plant your greens - lettuce, mustard, spinach, chard and kale. Turnips provide both greens and edible roots. Root vegetables such as carrots, potatoes and radishes are part of the early spring agenda.

For carrots to develop well, they require a loose, friable soil. Most of us garden in a tight, clay soil. I advise planting carrots in a raised bed, mixing generous amounts of compost into your soil, creating a porous and deep-rooting grow medium.