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

Lovely Lavender

Posted by Hugh on May 22nd, 2010

photo: ‘Munstead’ lavender

Lavender is a hardy shrub that thrives in dry alkaline soil. Lavender is commonly used as a food seasoning, a culinary substitute for rosemary. Dried flowers are crafted into table arrangements and lavender fragrance is captured in sachets and potpourris. Lavender is used to store clothes as a moth repellent. Some people store some under a pillow as a sleep aid, a form of “aromatherapy”. Bees produce a high-quality honey from the flower nectar.

There are two kinds of lavender. The shorter-growing cultivars of English lavender (Lavandula angustifolia) like ‘Munstead’, ‘Hidcote’, and ‘Lady Lavender’, flower in mid-May for one month. When cutback, English lavender blooms again in August. The taller more vigorous French lavender (recommend cultivars ‘Provenance’, ‘Grosso’ and ‘Super’) flowers only once in late June. For lavender oil production, I recommend ‘Super’.

Lavender is only successful planted in soil that is exceptionally well drained. An ideal soil pH range is 6.5 – 7.2. Grow on raised mounds and space plants 3 feet apart in the row and 6-8 feet in the row, if grown commercially. Other than for harvesting, prune plants back one-third in a ball shape in September. Lavender has very few disease and pests problems and possesses high drought tolerance.

FireBlight on Apples and Pears

Posted by Hugh on May 20th, 2010

Fireblight is a serious bacterial disease that afflicts apple and pear trees. Fireblight may appear in two distinct forms. From April to early May flowers and fruit clusters may blacken (die). From May to mid-June a more serious symptom (photo) is sudden dieback, almost overnight, of branch tips . Leaves appear as if someone had poured gasoline over the tree and torched it. Infected branch tips may also look curled, as a so-called “shepherd’s crook”.

To prevent the spread of fireblight, prune off all diseased wood, cutting back 6 – 8 inches into adjacent healthy shoots. Pruning is done either when first seen or when the tree is dormant. Disinfect the pruning shears after each cut, dipping the blades into either rubbing alcohol or 20% bleach to water solution. Remove all diseased prunings from the property. Do not compost.

When planning an apple or pear home orchard, avoid planting very susceptible varieties such as ‘Lodi’, ‘Gala’, ‘Jonathan’, ‘Rome’, and ‘ Yellow Transparent’. Among pear varieties, ‘Bartlett’, D’Anjou’, ‘Bosc’ and ‘Clapps Favorite’ are most susceptible, and ‘Moonglow’, ‘Maxine’, ‘Magness’, and ‘Seckel’ are moderately resistant to fireblight. Most Asian pear varieties are very susceptible.

No-Spray Shrub Roses

Posted by Hugh on May 17th, 2010

Photo: Carefree Sunshine Rose at UT Gardens in Knoxville, TN
Over the past decade the Knockout®, Carefree® and Home Run® series of shrub roses have altered the appearance of residential and commercial properties. From 2006 -08, no-spray rose trial was conducted at two University of Tennessee Research and Education Centers in Jackson and Crossville, TN and the USDA Horticultural Research Lab in Poplar, MS.
Over 135 cultivars were evaluated. “The ultimate disease test for roses is to test them south of the Mason-Dixon line where disease pressure is highest”, according to Dr. Mark Windham, UT Research Pathologist.

Shrub Roses Resistant (R) or Moderately Resistant (MR) to Black Spot and Cercospora Leaf Spot:
Carefree Sunshine (MR) – F
‘Fiesta’ (MR)
‘Golden Eye’ (R]
‘Hansa’ (R) – F
‘Homerun’ (MR)
Knockout Rose (R)
‘My Girl’ (R) – F
‘My Hero’ (MR)
‘Palmengarten Frankfurt’ (MR) – F
Pink Knockout (R)
‘Super Hero’ (MR)
’Wild Spice’ (MR) – F
‘Wild Thing’ (MR)
‘Wildberry Breeze’ (R) – F
F indicates rose is fragrant

Best of the Climbing Roses So Far– ‘White Dawn’

Posted by Hugh on May 15th, 2010

Since its introduction in the rose world over 60 years ago, ‘White Dawn’ has proven to be a top garden performer among climbing roses. The dark green, glossy foliage is very blackspot disease resistant. This very vigorous climber (hardiness zone 5 – 9) grows to 12 to 20 feet. Pure white double flowers are medium-sized (2-1/2″ to 3″). ‘White Dawn’ tolerates poor soils if drainage is good. It blooms best in a bright sunny spot.

‘White Dawn begins blooming in mid-May in the southern Appalachian region (Zone 6-b to 7-a) and repeats, off and on, through the rest of the growing year. Feed roses starting in early April and monthly to early September with Miracle-Gro®, Schultz®, or equivalent water soluble rose food @ 1 tablespoon per gallon.

Prune climbing roses in late winter (March) when new growth begins. On young climbers, simply remove all diseased, dead and tall nuisance canes. On older climbers, cutback the oldest rambling canes, favoring strong healthy one-year shoots which produce most of the rose blooms in May.

‘White Dawn’ is the first climbing rose to earn the University of Tennessee “No Spray” designation.

Growing Tomatoes in Containers

Posted by Hugh on May 10th, 2010

Apartment renters and townhouse and condominium owners till the soil in containers on their patio and deck. For containers the shorter growing determinate type tomatoes are a better choice. Spread out the harvest interval, by not planting all your tomatoes at one time. Start your last tomatoes from seed for June planting and harvest beginning in late September and October.

Container grown tomatoes need a deep container- at least 16 to 18 inches tall. A 5- gallon (or larger) pail or pot works well. Drill out several 1- inch wide drainage holes and add a few rocks in the bottom for ballast. Plant in a good growing media and add some inorganic fertilizer or organic bone and blood meal to increase fertility. Container-grown plants require more frequent fertilization than field-grown, as there’s less soil from which to obtain nutrients. For water soluble fertilizers, apply every two weeks.Here are some good varieties to try. The yield will vary with the variety:
• Slicers
– Bush Early Girl
– Bushsteak Hybrid
– Spring Giant
– Better Boy
– Jetstar
– Bush Celebrity
– Mountain Fresh Plus VFFN
– Super Bush
– Saladette (Roma type)• Cherry
– Golden Nugget
– Sweet 100 Patio
– Tiny Tim
– Patio
– Supersweet 100
– Sun Gold

Alternatives to Italian Cypress

Posted by Hugh on May 7th, 2010

'Sky Pencil' Holly at Chanticleer Gardens in Wayne, PA

Those of us who live north of Atlanta, GA (USDA zone 7-b) can not enjoy Italian cypress (Cupressus sempervirens), which are not hardy in most of the Southern Appalachian region (zone 6-a to 7-a). If you are designing a Mediterranean look in your garden, choose among select cultivars of these columnar evergreen shrubs:
Japanese holly (Ilex crenata) ‘Sky Pencil’

Upright boxwood (Buxus sempervirens) ‘Dee Runk’ and ‘Pyramidalis’

Red cedar (Juniperus virginiana) ‘Taylor’, ‘Brodie’, ‘Blue Arrow’, ‘Idyllwild’

Eastern arborvitae (Thuja occidentalis) ‘Techny’, ‘Pyramidalis’

Common juniper (Juniperus communis) ‘Pencil Point’

Alaskan cedar (Chamaecyparis nootkatensis) ‘Green Arrow’, ‘Van den Akker’

Hinoki cypress (Chamaecyparis obtusa ‘Vokel’s Upright’)

Arizona cypress (Cupressus glabra) ‘Limelight’, ‘Silver Smoke’

Rocky Mountain juniper (Juniperus scopulorum) ‘Skyrocket’, ‘Moonglow’ — needle foliage breaks down over time in warm 6-b to 7-a summers. Better in zone 6-a and further north.

‘Upright Japanese barberry (Berberis thunbergi) ‘Helmond Pillar’ – deciduous

Likely, you may be challenged by a lack of availability of several of these fabulous conifers at local garden centers. Often, an internet source becomes your best option for purchasing one or more.

Hybrid Decidous Azaleas Brighten The May Garden

Posted by Hugh on May 3rd, 2010

The bright reds, oranges and yellows of the hybrid deciduous azaleas (Rhododendron spp.) are lovely among tall shade trees which protect them from the harsh afternoon sunlight of summer. Because their bloodline is from our native piedmont azalea species in the Eastern U.S., hybrid deciduous cultivars possess exceptional disease and insect resistance rarely seen in the more popular evergreen forms.
This past weekend I saw this lemon yellow gem (pictured) in a friend’s garden in Lenoir, NC called ‘Sunny Side Up’. The very popular ‘Gibraltar’ (bright orange) has been blooming over the past 15 years blooming in my northeast TN garden next to ‘Gold Finch’ (yellow-gold).
Annual care is very minimal: Feed once after flowering with any slow release azalea or evergreen fertilizer. To invigorate the azalea, prune back one or two very tall woody branches near the base of the shrub to promote new shoot growth. The new branches will likely flower next spring and many more thereafter. One year established shrubs are also very drought tolerant.

New Blueberry Planting Require One Year Soil Prep

Posted by Hugh on April 30th, 2010

Fresh blueberries a few more weeks away from harvest

Blueberries are the easiest fruit crop to grow. Blueberries have few disease and insect problems. Birds become a significant problem as harvest time approaches, from mid-June through September. Blueberry culture is unique as the ideal soil pH range is 4.8 – 5.2. You should spend a year to lower the soil pH and raise the organic level to 3% and higher before planting blueberries.

Select a sunny location preferably with an east or northern exposure. Reduce the weed population by applying monthly applications of Round-up™ (glyphosate) herbicide over the planned blueberry site from April thru September. Have the soil in the blueberry patch analyzed. Follow the instructions on the soil test report, applying 0.2 lbs of elemental sulfur per 100 square feet for each 0.1 pH unit adjustment.

Sample calculation: you have cleared a strip of 6 feet wide by 16 feet long (approximately 100 square feet) for 3 plants. Your soil test recommends lowering the pH by 12 units (measured in tenths), so multiply .2 pounds sulfur x 12 units. The answer is 2.4 lbs of sulfur per 100 square feet. After 6 months, check the soil pH again to determine if you need add more sulfur.

Keep Your Eye on Red Buckeye

Posted by Hugh on April 28th, 2010

Red buckeye (Aesculus pavia) is the perfect small tree for an urban landscape. This native tree/large shrub flowers young in a full or part sun location. Numerous 5- to 9- inch long flower panicles are positioned on the tips of branches as decorative red candles in late April and May here in the southern Appalachian region (zones 6 thru 8).

Flowers open just before or after the leaves begin to emerge. Flower color on individual trees may vary from dark pink to scarlet red. Most trees are at their showiest in late April and early May. Hummingbirds arrive to pollinate the 1 ½ inch tubular blooms.

Lustrous palmately compound leaves dress the branches in rich green over the spring and early summer months. Disease and insect problems prove of little consequence, except that the greenery becomes scorched and spotted by late summer. Leaves drop prematurely in September, far ahead of other landscape trees.

The Fear of Trees

Posted by Hugh on April 28th, 2010

Dendrophobia is the psychological fear of trees. At recent Earth Day gatherings we learn of the importance of trees in the environment. Most of us know that tree topping is bad, yet the practice continues. Large trees are butchered (not pruned) every year.

Some tree topping stems from a “lemming mentality”, that is, “I did it because my neighbor did it”. When asked if the neighbor was very intelligent, most replied that they rarely sought their advice on anything.

Other folks need to control nature and their surroundings. They love large trees, but fear the damage that fallen limbs might wreak on home and property. Property owners living in areas recently hit with terrible storm are more prone to remove large trees or heavily prune them.

Power tools in the hands of inexperienced property owners cause additional damage to large trees. It’s called “chain saw massacre”, removing more than originally planned.

Finally, a local certified arborist told me: “People living in a neighborhood with topped or severely pruned trees felt cheated when their tree was properly pruned. They paid more for removing less, more time and skill involved to do it right.”