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

‘Cherokee Brave’– Outstanding “Red” Flowering Dogwood

Posted by Hugh on April 3rd, 2015

Cornus florida ‘Cherokee Brave’

Flowering dogwood (Cornus florida) is the most beautiful of U.S. native flowering trees (USDA hardiness zones 5 to 9). It typically grows 15-30 feet tall, but larger forms are known. The tree is broadly-pyramidal at a young age, branching is low, and matures with a rounded canopy. Spring bloom time usually overlaps with redbud (Cercis canadensis) which are finishing up. In 99.99% of the time, seedling dogwoods produce four petal-like white bracted flowers that measure 3-4 inches across.

‘Cherokee Brave’ produces dark pink bracts. Many texts describe the flowers as “dark red”. Pink color tones may not be as vivid if the spring weather is unseasonably hot or the tree is growing in warm southern climes. Cherokee Brave is a vigorous grower and bears flowers at an early age. The oval shaped leaves, 3-6 inch long, emerge with a slight reddish tint, and mature dark green by late spring. Foliage takes on intense shades of red, burgundy and purple in autumn before abscising.

Flowering dogwood is a popular small spring flowering tree in the northeast and mid-South regions of the U.S. Troubles with two fungus diseases, anthracnose and powdery mildew, has caused it to fall out of favor. Cherokee Brave exhibits above average resistance to both diseases, particularly the latter. Flowering dogwood is utilized as a specimen or small grouping on residential, parks, and commercial properties.

Plant flowering dogwood in an average well-drained soil and in full sun to part shade. For long life, it prefers a moist, organically rich, acidic soil in partial sun. The tree benefits from 2 – 4 inches of mulch to keep tree roots cool and moist during the summer. Following a 2- year establishment timeline, flowering dogwood exhibits good drought resistance.

Flowering dogwood’s brightly red drupe fruits are relished by birds and 4-legged creatures in the forest including deer. Their flowers attract numerous early arriving springtime butterflies. Its rugged alligator hide bark and branching silhouette are special winter features.

Building A Wildlife Wall In Your Garden

Posted by Hugh on April 1st, 2015

Wildlife Wall in Bristol, TN Garden

Many beneficial garden insects, such as ladybugs and ground beetles, struggle to find habitats in our manicured gardens. Consider creating an attractive wildlife wall to lure them in. Keep them happy and they will help reduce harmful pest populations.

Dr. Douglas Tallamy, through his thoughtful book “Inviting Nature In” and other writings, have spurred gardeners to invite more beneficial critters into their gardens. One fascinating project is to build a wildlife wall. It is a very simple task to put one together. No two may look alike, so add your own creativity.

A wildlife wall is a shelter full of all kinds of holes and crevices so that any creature (toads, spiders, and any other insects) that needs a hiding place that wants to can move in. Within a short time you may observe mason bees, ants, even a tree frog. Some of nature’s beneficials such as snakes, wasps and hornets will come, but may not be welcome.

Suggested Materials:

Sedum, Sempervivum, or Delasperma plants
cinder blocks and/or bricks (with holes in them)
small blocks of wood, drilled with different sized holes
roof or drainage tiles
sheets of plywood or planks of wood; old wooden pallets
straw, corrugated cardboard, slate chippings, various diameters of bamboo, clumps of moss, twigs
soil and/or sand

Select a quiet (less frequented) area of the garden and establish the base using cinder blocks, bricks, and/or tiles. Leave plenty of gaps where critters will find shelter and move in. Use roof tiles to keep excess moisture out.

Solitary bees may make homes in the bamboo cane holes. Ladybird beetles will create laying sites in rolled up corrugated cardboard. Create a living roof by planting with iceplants, sedums, sempervivums, and other arid-loving plants which attract numerous pollinators.

Once friendly critter inhabitants have moved in, your wildlife wall requires no attention. Expect some organic parts (wood, straw, moss, etc.) to decay over time and need some repair. Straw may be taken away by nest-building birds elsewhere.

The Forsythia Revolution

Posted by Hugh on March 29th, 2015

Standard size forsythia (Forsythia x intermedia)

Forsythia ‘Gold Tide’

In most areas of the U.S., the golden yellow blossoms of forsythia (Forsythia x intermedia) signals that worst of winter weather is almost over (USDA hardiness zones 4 to 8). Over 2-3 weeks bright yellow flowers cover this easy to grow shrub. Priced at under $20, a good-sized forsythia shrub is a bargain, often used to lure customers into the door.

Forsythias are small to medium-sized ornamental shrubs maturing between 4 to 10 feet tall by 5 to 12 feet wide depending on cultivar. It has an upright oval, open, growth habit with long arching growth habit. The shrub can easily take on a straggly appearance unless pruned every 1-2 years. Dwarf and semi-dwarf cultivars are available; the most popular form is Gold Tide™ at 3 to 4 feet tall and 5 to 6 feet wide.

Other popular cultivars include:
‘Sunrise’- compact 5 feet tall habit
‘Golden Nugget’ – grows to 5 feet tall and wide
’Spring Glory’ – 6 to 7 feet tall with pale yellow flowers and an upright habit.
‘Lynwood Gold’ – popular old fashioned cultivar with bright yellow blooms
‘Northern Sun’ – floral buds are hardy to -30°F.

Forsythia is best grown in full to partial sunlight (minimum 6 hours sun for best flowering). The shrub flowers less and branches grow tall and lanky in partial shade. It prefers moist, well-drained soils but adapts to poor soils, is not pH sensitive, and is very drought tolerant. It is rarely troubled by disease or pest troubles.

Vigorous growing forsythias are best pruned within 2-3 months after spring flowering. Most attention should be directed to remove thick (oldest) wood; this greatly will reduce the height of the shrub. Also remove weak basal suckers less than pencil thickness. Flower buds are set in mid- to late-summer. Late summer pruning should be avoided.

The 3 – 4 inch long medium green leaves turn an unexciting off-green, yellow, and purple in autumn before abscising. The olive to yellow-brown wood is covered with raised lenticels. Floral buds are evident by early fall and a few often flower during warm autumn days.

Forsythia is utilized as a specimen shrub or en masse as a deciduous hedge or intermediate privacy screen.

Fruit Gardening In Containers

Posted by Hugh on March 26th, 2015

Great packaging along with exciting breeding has ignited interest in growing small fruits in containers. In recent years the BrazelBerries^™ fruits have become popular at garden centers.

Brazelberries is the creation of the Brazelton family of Fall Creek Farm & Nursery, Inc. in Oregon, who have been propagating and growing berry plants since the 1970’s. Their breeding program is focused on offering tasty and beautiful berry plants for containers and gardens. Fruits are easy to grow and are both delicious and nutritious to eat.

Easy care BrazelBerries make attractive landscape plants in a sunny garden spot as well as in decorative patio and deck containers.

Plants are compact in size and can be grown in #3 or #5 nursery containers or in larger ceramic urns.
Great tasting for your guests snacking or as appetizers at a summer garden party. Try Peach Sorbet® blueberries, Jelly Bean® blueberries, or Raspberry Shortcake® raspberries.
Mix with small shrubs, perennials and annuals along a pathway or group several together for ornamental beauty.
Create an edible landscape whether for snacking or as a wildlife attraction.
Clip of fruiting branches to utilize in floral arrangements.

To maximize fruit production, fertilize with Miracle Gro™ or Peters™ every 2-3 weeks during the growing season and prune plants in late winter before new spring growth begins. Fruit plants are disease resistant but may have occasional problems with aphids.

Better Disease Resistance With Mountain Tomato Series

Posted by Hugh on March 24th, 2015

'Mountain Pride' Tomato (Photoprovided by Dr. Randy Gardner)

‘Mountain Pride’ Tomato (Photo credit: Dr. Randy Gardner, retired NCSU Plant Breeder)

Tomatoes are attacked by several diseases and insects. Most serious diseases are early blight, spotted wilt virus (TSWV), fusarium wilt (FW), Stemphylium Gray Leaf Spot (St), Alternaria leaf spot (A), and root knot nematodes (N).

Major insect problems are aphids, thrips, stink bugs, blister beetles, fruit worms, horn worms, leaf miners, fruit flies, and white flies.

Some problems are nutritionally- or environmentally-caused including blossom end rot (low soil calcium, lack of soil moisture), fruit cracking (excess water and high temperatures), sudden wilting (root damage from cultivation or drowning), blossom drop (drastic temperature changes, poor nutrition), and sunscald to fruit (loss of foliage from disease).

The most impressive series of disease resistant tomato varieties has come from the breeding program of Dr. Randy Gardner at the Mountain Crops Research Station in Western North Carolina. Over a past twenty years, he has released over a dozen very productive, great tasting tomato varieties starting with Mountain Pride. Here are nine in the series:

Mountain Pride – crack resistant large red fruits; VFFASt resistant
Mountain True – indeterminate late blight, resistant to early blight and fruit cracking; sweet tasting 2 oz. campari tomato
Mountain Fresh – determinate, late producing; large 10 oz. fruits with red skin and red flesh color; VFFN resistant
Mountain Majesty – large 3 ½ inch crimson fruit; FW, VW, and TSWV resistant
Mountain Glory – high yielding 12 oz. red globe shaped fruits; VFF and TSWV resistant
Mountain Spring – determinate, bush-type tomato; large 9 oz. fruits; VF resistant
Mountain Magic – indeterminate, highly disease resistant; 2 oz. fruits; VF resistant
Mountain Supreme – determinate, mid-season, red globe; VF, early blight resistant
Mountain Belle – high yielding small bright red cherry tomatoes; crack resistant

Code Symbols meaning:
V Verticillium wilt
F Fusarium wilt
FF Fusarium, races 1 and 2

New Redbuds With Striking Foliage Abound

Posted by Hugh on March 21st, 2015

New Ruby Falls’ redbud

New ‘Rising Sun’ redbud

Over the past decade Eastern redbud (Cercis canadensis) has undergone a real facelift. This native spring flowering tree can no longer be solely identified by its green heart-shaped leaves. New foliage color choices will decidedly catch your eye and win you over. With some reservations most redbud cultivars fall within USDA hardiness zones 5-9.

Purple-leaf ‘Forest Pansy’ redbud, released over 70 years ago, continues to be very popular. Today, two gold-colored foliage cultivars, ‘Rising Sun’ and ‘Hearts of Gold’, are catching on with landscapers. The dark yellow tint holds all spring and summer long. Brand new Solar Eclipse™ flaunts striking peach-orange foliage.

In the white variegated leaf category is new Alley Cat™, selected by Allen Bush of Jelitto Seed. The variegated foliage does not burn or fade like old-timey cultivar ‘Silver Cloud’. Floating Clouds™, a new Don Shadow introduction, boasts green foliage generously splashed in white; it does not scorch in the summer sun.

Gardeners with limited space may opt for low weeping redbud forms. Old-timers like ‘Covey’ (Lavender Twist®) and ‘Traveller’ continue to be popular green leaf weepers. New weepers include Ruby Falls™ and Whitewater™. Ruby Falls is essentially a weeping ‘Forest Pansy’ with striking white and green variegated spring foliage. Whitewater is a tree weeper with green leaves sprinkled with white flecks.

Why Mophead Hydrangeas Do Not Bloom

Posted by Hugh on March 18th, 2015

Hydrangea macrophylla at Morris Arboretum in Philadelphia

Hydrangea ‘After Midnight’ in Savannah, GA Garden

The introduction of Endless Summer® hydrangeas in the 1990’s got gardeners excited about growing mophead hydrangeas (Hydrangea macrophylla) again. Mophead hydrangeas bloom both on old wood in the spring and again on new wood in mid-summer. Flowers have either a blue/pink color depending on the pH of the soil. Endless Summer hydrangeas bloomed in cooler areas previously off limits for mopheads.

Bad Winter? Endless Summer hydrangea series are still very dependable and have spawned a number of new series. Still, abnormally cold weather in many areas may greatly decrease late spring/summer flower numbers. On the first day of spring ask yourself how the previous winter felt personally. If you rate the winter as bad, likely spring mophead bloom will be less.

Available sunlight. In the north (zones 4 – 5), mopheads can handle almost full day sun. In zones 6 and 7 reduce to 4-5 hours of mostly morning sunlight, and in zone 8 to 9 in day-long high shade. Less than optimum light levels means less flowers.

Wrong Cultivar. The marketplace is very confusing with many non-hardy cultivars still being sold.

Late Freezes. Hydrangea buds open very early. Late spring freezes frequently destroy or injure flower buds and new growth. Keep the crown (plant base) heavily mulch until mid-May in most areas.

Over-fertilizing hydrangeas may result in dark green foliage (a good thing) and fewer flowers (not so good). In USDA zones 4 and 5, do not fertilize past August 15th, as it may lead to winter injury.

Overwatering mopheads may push too much growth and fewer flowers. On hot summer days seeing mophead leaves wilting in mid-day is very common. Irrigate once weekly, 1 to 1 ½ inches of water, rather than a little bit every day.

Pruning mopheads in the fall is a mistake. Spring flowers are borne on the old wood.

Old-fashioned Star Magnolias Very Beautiful Start Of Spring

Posted by Hugh on March 15th, 2015

Star Magnolia in Northeast TN garden

Multi-petalled Star Magnolia

Star magnolia (Magnolia stellata) is a multi-branched shrub or small tree which is native to Japan (USDA hardiness zones 4 to 8). This early flowering magnolia is noted for its compact form. A mature tree form grows 15 to 25 feet tall, 10 to 20 feet wide, and exhibits an umbrella-like canopy. Each flower typically contains 12-18 narrow thick fleshy petals (referred to as “tepals”).

In southern U.S. climes, its white flowers emerge weeks before the leaves, often a week or two before the official start of spring. In a colder northern spring it may wait to bloom in mid-April. White fragrant blooms are often damaged by spring frosts, but the remaining buds wait to open; flowering may continue over 2-3 weeks.

Star magnolia is easily grown in an average, medium, well-drained soil in full to part sun (4-hours minimum). It prospers a rich organic soil. It is best sited sheltered away from high winds; avoid a southerly exposure where flower buds may open too early and get frost-killed. Star magnolia suffers from few serious disease or pest problems when properly sited.

Star magnolia stands as a handsome small landscape tree or large shrub near a patio or in front of an evergreen background. Plant several together as a hedgerow. Star magnolia is best planted in late winter into spring, either balled and burlapped (b&b) or container-grown.

Little Bluestem – Beautiful And Environmentally Correct

Posted by Hugh on March 12th, 2015

Schizachyrium_scoparium 'StandingOvation' (photo courtesy of North Creek Nursery, Landenberg, PA

Schizachyrium_scoparium ‘StandingOvation’ (photo courtesy of North Creek Nurseries, Landenberg, PA

Little Blustem at Brooklyn Botanical Gardens in NY in October 2014

Little Bluestem (Schizachyrium scoparium) grows in old fields, meadows and prairies, and along roadsides across the United States and Eastern Canada (USDA hardiness zones 3-8). It forms dense clumps 2- 3 feet tall and 12 -18 inches wide. This warm season grass prefers a well-drained soil and full to part sun site. It looks its best in low nutrient soils; when fertilized or frequently irrigated, clumps tend to flop over. It grows easily from seed. It is very drought tolerant and survives over many years. A new seeding of little bluestem will be very small its first year as this native grass puts much of its energy into growing roots first.‘Standing Ovation’ is an outstanding vegetatively propagated cultivar introduced by North Creek Nursery in Landenberg, PA. It maintains a tight, upright habit throughout the entire season. Sturdy erect stems start out with a bluish cast; grass blades and stems turn fiery shades of yellow, orange, brown, red and purple in fall and winter.

Gardeners and landscapers should take advantage of its strong vertical presence of this unique cultivar. It grows 3-4 feet tall and only 6-12 inches wide. Leaf blades tend to be thicker than on other bluestem; disease and insect problems are rare and usually caused by poor site selection.

Plant little bluestems to edge a garden path, driveway or sunny flower border to catch textural contrasts. Little bluestem is highly deer-resistant. Several species of skipper butterfly caterpillars feed on the leaves and birds use it for cover and for nesting material.

Double Knockout® Roses

Posted by Hugh on March 9th, 2015

‘Pink Double Knockout’ roses at UT Gardens in Knoxville, TN

Knockout® roses continue to wow gardeners across the U.S. (USDA hardiness zones 5 to 9). The original Knock Out series grew 5 to 8 feet tall and 4 to 6 feet wide. Shorter growing Double Knockout® series make better fit in most urban gardens at 3 to 4 feet high and 3 to 4 feet wide. Double blossoms have the look of hybrid tea or floribunda roses. Colors range from red, pink, coral, and yellow.

All Double Knockout roses are bred for its resistance to common rose pests and diseases. They bloom heaviest in May and June, retreating in the heat of summer and finish with a flurry of color in late summer and fall. They hold up under rough weather and moderate drought.

Roses are best planted from spring thru mid-summer to permit roots adequate time to grow deeply before winter arrives. Double Knockout® roses should be planted 4 feet apart in a garden site that receives 6 to 8 hours of sun most days and in well-drained soil that ranges between pH 6.0 and pH 6.5. Roses need good air movement, so don’t crowd them.

Dig a wide hole to accommodate the roots from the container grown plant. Set the root ball slightly shallow in the hole. Backfill the hole with soil and water deeply. After planting, water regularly (usually weekly) until the plant becomes well established. Apply 2-3 inch depth of an organic mulch to conserve soil moisture and reduce weed infestation. Do not pile mulch around the rose trunk.

Fertilize Double Knockouts with a water-soluble fertilizer monthly from early spring until September 15 (no later). An alternate feeding method is to use special organic based rose foods sold at most garden centers.

In late winter or early spring prune roses when they are still dormant to remove all dead or damaged wood and to maintain the roses at a desired size.