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

Tips on Planting an Apple Orchard

Posted by Hugh on February 17th, 2010

Apples are easy to grow with a little planning. Select the varieties based on what you like to munch on. Visit the local supermarket and buy several to sample. Some apples taste better in pies and in sauce. Some varieties have a short shelf life and must be consumed within a few weeks after picking or purchase. Favorites like ‘Granny Smith’ and ‘Rome’ are good for eating, baking pies and making sauce.
How long are you willing to wait? Apple trees grafted on seedling rootstocks begin bearing fruit in 7-8 years. Varieties grafted to dwarf (grow 9 feet tall) or semi-dwarf (12-15 feet tall) rootstocks begin bearing a crop within 3 years.

Young trees should be allowed to grow and never permitted to bear fruit. Space semi-dwarf trees 15-18 feet apart and dwarf trees at least 8-10 feet apart. Plant two or more different varieties for adequate cross pollination.
Plant trees either in late winter (before spring) or in the autumn in an open sunny site. Mulch trees to 2- 3″ depth with a minimum 18 inches diameter around each tree trunk. In late fall pull mulch away and loosely wrap the tree trunk to a 2 foot height (add another foot if you live in heavy snow zone) with hardware wire (cloth) to prevent rabbits and pine voles (mice) from chewing on the tender sugary bark of a young fruit tree.
Finally, order trees early and request delivery before the first day of spring.
Check with your local Extension agent or agricultural university for additional information about growing apples.
Popular apple varieties:

Gala-yellow-orange to red /fresh/early
Empire -dark red over green background/ fresh, cooking/ early

Red Delicious -red/fresh/early midseason
Jonagold-yellow with light red stripes /fresh, cooking /midseason
Golden Delicious-yellow green to light yellow/fresh, cooking /midseason
Fuji -green with red stripes/fresh /late midseason
Stayman-blush to red /fresh, cooking/late
Rome-blush to red /fresh, cooking /late
Granny Smith -greenish-yellow/fresh,cooking/late

U.S. Native Viburnums And Viburnum Beetle Susceptibility

Posted by Hugh on February 16th, 2010

photo -Arrowwood viburnum in late summer

A trip to Carolina Native Plants Nursery in Burnsville, NC gave me this idea to list those viburnums which are U.S. natives (USDA Hardiness zones 6 and 7). All are worthy for planting in your landscape in full sun except where noted. All attract birds and other wildlife to your property.

Mapleleaf vibrnum (V. acerifolium) – prefers dry shade sites
Witherod viburnum (V. cassinoides)
Arrowwood viburnum (V. dentatum) – hardy north into zone 3
Sheepberry, nannyberry (V. lentago) -hardy north to zone 3
Smooth witherod viburnum (V. nudum)- superior cultivar ‘Winterthur’
Small viburnum (V. obovatum)
Black haw viburnum (V. prunifolium) -in part shade areas
Rusty blackhaw (V. rufidulum)
American cranberrybush (V. trilobum)- try cultivar ‘Wentworth’, which is hardy to zone 2

Superior cultivars of arrowwood viburnum is currently available and are utilized as a 5-7 foot deciduous screen or hedge. For woodland plantings blackhaw and maple-leaf viburnums are at home in shady areas.

According to Cornell University entomologists, most native viburnums are susceptible to viburnum beetles. This serious pest can be managed by timely applications of horticultural oils, spinosad (organic pesticide), and insecticidal soaps in late April and early May, targeting hatching eggs and young larvae which feed on the new tender foliage. Insecticides containing pyrethrins are effective, but also will kill beneficial insects in the garden.

Fragrant Wintersweet in Bloom Now

Posted by Hugh on February 15th, 2010

It’s mid-February and you may have already missed seeing the fragrant yellow blossoms of wintersweet (Chimonanthus praecox). Its tiny flowers, 3/4 to 1 inch across, open in the coldest period of the winter season. Blooms are weather-proof, rarely injured when nighttime temps dip below freezing in zones 6 and 7. Bloom injury likely occurs as evening temps approach zero °F.
Wintersweet is a 10-15 foot tall and wide shrub, and grows well in any soil type provided it is adequately drained. Summer foliage is lustrous dark green, turning yellow-green in fall before dropping its leaves.
Every 5 to 6 years, a tall, often leggy fragrant wintersweet requires a complete rejuvenation. Prune the entire shrub back to within 4-6 inches from the ground after blooms have vanished in late March. It will grow back rapidly and bloom again next January.

Thermotropism in Plants

Posted by Hugh on February 15th, 2010

How cold is it outside this morning? Look out the window….perhaps your rhododendron is telling you.

On very cold winter mornings some broadleaf evergreen shrubs, like rhododendron and daphniphyllum in my landscape, droop down and/or curl up. (see photo). This is a specific response by some plants to sub-freezing temperatures, called “thermotropism”.
Scientists do not fully understand the cause of this foliar response. It may have something to do with leaf cell hydration. Thermotropism also may protect leaves during periods of high irradiance by sunlight. It may protect from cold temperature injury during daily thawing and re-freezing inside the leaf of some broadleaf evergreens.

On most days, leaves unfurl to their full natural position by late morning as temps rise above 32 °F (0 °C). Remember to water evergreen shrubs every 2-3 weeks if natural rainfall and snowfall are more than 60% below seasonal averages.

Privacy Screening – Avoid Using Leyland Cypress

Posted by Hugh on February 11th, 2010

Privacy Screen Using Leyland Cypress

‘Green Giant’ arborvitae and Cryptomeria (Japanese cedar) have proven more dependable over the years than Leyland cypress across Tennessee, Virginia, North Carolina, and South Carolina. Leyland cypress is susceptible to three serious foliar diseases.
Some people love the faster growth of Leyland cypress. Leyland cypress may be weak-wooded, as reported by some gardeners this current frigid winter. Fast growing species tend to be weak-wooded. This may be the problem with the heavy snow and high wind storms this past winter.
Ask yourself “do you really need to construct a 50-60 foot green wall so you can hide from the sight and noise of your neighbors”. A 10 to 12 foot screen is usually what most people need.
I would sway you to choosing a shorter and slower growing needle evergreen like Emerald™ arborvitae, any tall-growing evergreen holly (Ilex spp.) or an evergreen flowering shrub like Pragense viburnum.

New Dogwoods for Mildew Resistance

Posted by Hugh on February 11th, 2010

‘Joy’ ‘Mist’ ‘Snow’ ‘Blush’

Powdery mildew has become more of a problem across the southeastern U.S. over the past ten years on flowering dogwood (Cornus florida). University of Tennessee plant scientists have developed a series of mildew resistant dogwoods (pictured above). Each cultivar is sold under the Appalachian series of dogwoods. In cool spring climates, the white floral bracts of ‘Appalachian Blush’ will develop a pinkish blush. Generally, the color blush is rarely observed in Tennessee, Virginia, Georgia, North Carolina and South Carolina.

These cultivars join ‘Cherokee Brave’ (dark pink bracts) as the only powdery mildew resistant dogwoods. Only in a rare occasion will you need to spray these dogwood cultivars.

‘Bosque’ Lacebark Elm — a Better Choice

Posted by Hugh on February 10th, 2010

(New planting of Allee elm pictured)

Recent storm damage has caused a re-evaluation, whether to continue to plant the cultivar Allee®, also called ‘Emerald Vase’. Urban foresters around the state of Tennessee report that limb breakage and clean up around Allee elms is greater than around other cultivars. Bosque seemed to fare much better.
Lacebark elm (Ulmus parvifolia) is a beautiful medium -sized street and shade tree. Its use in urban street plantings has become popular over the past decade. The three leading cultivars of lacebark elm are Allee®, Athena® and Bosque™.
The tree earns its name from the delightful orange or brown color mosaic or puzzle-like pattern over the main trunk (s) and branches. The autumn leaf color is rarely memorable and the small 1-2 inch leaves fall without much fanfare and with little mess.

Get your lacebark off to a long and prosperous life by supplying extra water and light fertilize feeding the first two years. In the first two years after planting, a young tree needs deep watering every two weeks in the late spring and summer. An established lacebark elm exhibits exceptional drought tolerance.

If you or your city, town or village is planting lacebark elm in your housing subdivision, request that they select Bosque elm.

‘Clothed in Glory’ daylily

Posted by Hugh on February 10th, 2010

(Photo courtesy of The Daylily Nursery)

Browsing through several garden catalogs on this snowy February day, I spotted a new daylily gem called ‘Clothed in Glory’ from The Daylily Nursery, a mail order emporium in Rock Island, TN.

Tim Hitchcock, nursery owner, describes ‘Clothed in Glory’ as an 18- inch tall lavender beauty possessing regal golden frilled-edged petals with a yellow center eye. Each flower measures 7 inches across and the floral bud count is enormous. ‘Clothed in Glory’ re-blooms in early fall if kept watered and fertilized over a hot, dry summer.

Daylilies are low maintenance perennials which grow in any well-drained soil. Very few disease and insect pests bother them. Plant them in early spring and daylilies will bloom their first summer (late spring). Divide daylilies every 5-6 years to maximize flower numbers.

With over 84,000 registered daylily daylilies in the world marketplace, gardeners still rally around the popular 18-22 inch tall landscape cultivars: ‘Stella D’Oro’, ‘Pardon Me’, and ‘Happy Returns’. I recommend adding ‘Clothed in Glory to your garden this spring.

Salt Damage on Trees

Posted by Hugh on February 1st, 2010

Winter 2010 lingers on across Tennessee, Virginia and North Carolina. The white coating of de-icing salts over streets and highways can damage many trees and shrubs. Salt spray and salt deposits may also leach into the soil and become equally damaging. Plant species vary in their sensitivity to salt injury.
Browning of the tips of needle and broadleaf evergreens is a typical symptom of salt injury. Needle loss can be an extreme result, with evergreen branches becoming progressively bare. Often, evergreens become so weakened and stressed that new spring growth does not slow the needle/leaf loss. Overall tree health gradually declines.

The following practices can minimize salt injury to trees and shrubs:
1. Applications of water will leach some salt out of the root zone. Plentiful spring rainfall will help in this leaching/cleansing process. As much as 6 inches of water is needed to leach about half the soluble salts. In addition, applying gypsum (calcium sulfate) displaces the sodium in the soil.
2. Plant trees in salt-prone areas that are less vulnerable to salt damage. All trees are affected by salt to some degree, but some species are more tolerant than others. A listing of the susceptible and resistant trees to salt (University of Tennessee Extension publication SP-610) appears below.
3. In future plantings, avoid setting salt susceptible tree species in areas where salt-laden brine and slush are likely to accumulate.
4. Plants that are injured and exhibit dieback should be watered, pruned and fertilized.
Fresh mulch may be applied to help reduce water loss during the normally dry summer ahead. Weakened or stressed trees are also more susceptible to disease and insect pests.

Table 1. Salt Susceptibility of Trees
Vulnerable to Salt
Red Maple – Acer rubrum
Sugar Maple – Acer saccharum
Mimosa – Albizia julibrissin
Serviceberry – Amelanchier spp.
American Hornbeam – Carpinus caroliniana
Dogwood – Cornus florida
Hawthorn – Crataegus spp.
American Beech – Fagus grandifolia
Yellow Poplar – Liriodendron tulipifera
Crapemyrtle – Lagerstroemia spp.
Magnolia – Magnolia grandiflora
Spruces (most) – Picea spp.
Eastern White Pine – Pinus strobus
Scotch pine – Pinus sylvestris
Lindens – Tilia spp.
Eastern Hemlock – Tsuga canadensis

More Tolerant to Salt
Norway Maple – Acer platanoides
Buckeyes – Aesculus spp.
Birch – Betula spp.
Hickories – Carya spp.
Ash – Fraxinus spp.
Ginkgo- Ginkgo biloba
Honeylocust – Gleditsia triacanthos
Black Walnut – Juglans nigra
Eastern Redcedar – Juniperus virginiana
Cottonwood/Aspens – Populus spp.
Cherries – Prunus spp.
Oaks (most) – Quercus spp.
Black Locust – Robinia pseudoacacia
Yews – Taxus spp.
Elms – Ulmus spp.

Ferns in Your Garden

Posted by Hugh on January 22nd, 2010

I recommend adding ferns in your shade garden. Ferns offer very fine textured foliage. Plant’em in clumps of three or more. Select the proper fern by your garden site, e.g whether it is likely dry or moist soils. Some grow surprisingly well in full sun, but most prefer partial to full shade. Don’t buy a collection of different ferns for planting in one garden place. Instead, select them by their light and soil moisture needs.

Here are four species which are easy to grow:

Christmas fern (Polystichum acrostichoides)
Autumn fern (Dryopteris erythrosora)
Lady fern (Athryium felix-femina)
Northern maidenhair fern (Adiantum pedatum) – (pictured)- prefers well-drained, highly composted soils and supplemental moisture during long summer dry spells. Keep soil near pH 7.0 (neutral) by occasional liming every few years if soil pH drops.

All four are not finicky, demonstrate good drought tolerance and grow in soil with little to no additional soil prep. Ideally, you should grow them in a richly composted garden soil along with adequate moisture over long dry spells. Bi-monthly feeding with a water soluble fertilizer such as Miracle-Gro™, Jack’s™, or Nature’s Source™ from April to August will get all off to a good start in the first year.