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

Franklinia – Native Tree Lost in the Wild

Posted by Hugh on September 27th, 2010

Franklinia (Franklinia alatamaha) is a wonderful small tree or large multi-trunked shrub with fragrant white camellia- like flowers. Franklinia is related to world-class flowering shrubs like camellia and stewartia. Its white 3 – 3 ½ inch camellia-like flowers appear from early August thru late September.

Franklinia is winter hardy in the Southern Appalachian region (USDA zones 6-7). Its fibrous root system prefers a well-drained, richly organic, and acidic soil much like azaleas and rhododendrons. Don’t subject to extended summer droughts or frigid drying winter winds.

Fall color is respectable with autumnal hues of red, orange and burgundy. The bark on a young tree is distinctively striped, and the main branches become fissured with age.

The species was discovered by plant explorer John Bartram and his son William growing along the Alatamaha River in southeastern Georgia in 1765. Natural populations are now extinct. All franklinia trees growing today are descendants of the Bartrams’ collected seeds.

Franklinia is a finicky grower, but very much worth the challenge. A deadly fungal root disease, Phytophthora cinnamoni, may have led to its demise in nature, is its Achilles’ heel. A 2-3 week long invasion of Japanese beetles in August may shorten individual bloom life by half.

Substitute Dwarf Cryptomeria for Yews

Posted by Hugh on September 25th, 2010

For better garden performance and different textural look around a home foundation, plant the dwarf shrub forms of Japanese cedar (Cryptomeria japonica). Dwarf cryptomeria is an excellent substitute for Japanese yews (Taxus spp.) or ‘Helleri’ hollies (Ilex crenata) which often struggle in heavy clay soils, particularly those poorly drained.

‘Globosa Nana’ (photo) has a “cookie-cutter” round, globular form, and rarely needs pruning. ‘Globosa Nana’ has bright green floiage and grows 3-6 feet tall and wide. The cultivar ‘Black Dragon’ has dark green foliage and a pyramidal growth habit (8-12 feet tall and 4-5 feet wide). Both are planted as single specimens or grouped several together They are slower growing than their taller 40-50 feet columnar counterparts.

Cryptomerias prefer well-drained, slightly acidic soil and are planted in an open sunny location. Young shrubs are remarkably shade tolerant. Their dark evergreen foliage turns a bronze to purple color during the coldest part of winter. By early spring the bright or dark green color returns to their short needles. Fertilize shrubs annually either in February or March.

Garden centers sell either balled and burlapped (b&b) or container-grown stock. Cryptomeria is best planted from February thru October. This evergreen demonstrates superior heat and drought tolerances once established in the landscape for two years.

Truly, Fall Is For Planting

Posted by Hugh on September 22nd, 2010

The seasonal theme at garden centers is “Fall is for Planting”. Plant sales are everywhere. If you have recentlypurchased a home and your budget is tight, buy yourself an early, but practicable holiday gift- a deciduous shade tree planted on the southwest side of the home. In a few short years, this tree will reward you with lower summer cooling bills.

Some good deciduous choices are red maple, green ash, tulip poplar, sawtooth oak, willow oak, and basswood. Garden centers push to reduce store inventories, saving usually 30%-40% off the listed price. I offer six basic landscape planting tips:

1. Plant only deciduous trees in the front of the home, and evergreen trees on the other three sides (pines, hemlock, etc.)
2. Dig a hole three times the diameter of the root ball
3. Plant shallow, barely covering the root ball and put no soil amendments in the hole
4. Add three inches of an organic mulch (wood chips, pine straw or compost) over the widthof the planting hole and not piled up against the trunk
5. Slowly deliver 10 gallons of water to each tree after planting
6. Do not fertilize newly planted trees and shrubs until the first day of spring.

Coppicing – Renewal Pruning for Old Rhododendrons

Posted by Hugh on September 14th, 2010

'Janet Blair' Rhododendron in Need of Coppicing

Coppicing is a form of renewal pruning because the entire shrub is lopped off to the ground. It is a drastic pruning technique primarily used on shrubs that flower and fruit on new or summer wood, those that flower in late June or later. Coppicing is renewal pruning but is so simple that gardeners is called “no brainer” pruning.

In late February, about 4-5 weeks before spring growth begins, cutback the shrub(s) leaving 3-5 inches of stubble for the new growth to emerge from the adventitious buds near the soil surface.

Coppicing invigorates old shrubs, brightens foliage color and increases fruit size. Overgrown rhododendrons, including deciduous azaleas, plus hollies, pieris and mountain laurels may be coppiced in the fall beginning in late September thru October. It eliminates disease and/or insect- riddled stems and twigs without resorting to pesticides.

Over-grown rhodies should be well-established and healthy; old shrubs in poor vigor will likely not regrow. They may be cut back severely to stumps with no leaves. Healthy plants recover, a year before the plant has much foliage and two or more years before they flower.

Hand clippers, loppers, and saws should be sharp. Do not use string mowers (weed-eaters).

Rooting Proliferations on Daylilies

Posted by Hugh on September 11th, 2010

Photo: daylily proliferations on old floral scape in late August

Proliferations are small plants which grow on the spent floral scapes of daylilies (Hemerocallus spp.). Not all daylily varieties produce proliferations. Propagating and growing proliferations is a simple way to increase the number of new daylily plants quickly.

Prune off each plantlet from the old floral scape as they form. Stick each one into a prepared ground bed. Label or tag the cultivar from which the proliferation is taken. Over the next two weeks, keep the soil/media moist. The proliferations will expand their roots into the media.

An alternative approach is to set each proliferation into its own 4-6 inch pot containing coarse sand or soil-less media or mix. Keep the media moist and grow new daylily plant into late fall. If you live in a cold winter (USDA zone 6 and colder), bury the pot to prevent serious freeze injury or grow in a protected cold frame. In areas experiencing mild winters (USDA zones 7 and warmer), transplant newly rooted plants into a ground bed before November 1st.

Plantlets should begin flowering within 18-24 months. If, in haste, you had removed the old floral scapes after spring bloom, don’t be in quite a hurry next summer.

Hardy Camellias for Southern Appalachian Region

Posted by Hugh on September 10th, 2010

'April Tryst' camellia (Spring bloomer)

Several camellias bloom reliably either in the fall and or early spring in most areas of Tennessee within USDA hardiness zone 6. In the colder higher elevations above 2000 feet, hardy camellias require some additional shelter to successfully bloom over 6 – 8 weeks. Flower colors range from white, many shades of pink, and red.

Growing camellias is very much like that of rhododendrons, but with a lot less hassle with disease and insect pests. The foliage of hardy camellias remains lustrous green year-round. Camellias relish a richly organic, well-drained, and acidic soil.

A garden site with a northeasterly exposure is a perfect nook, partially shaded from the harsh mid-day summer sun and protected from the cold drying winds of winter.

Common name: Zone 6 Hardy camellias

Botanical name: Camellia spp.

Cultivars recommended: Over 40 available; recommend starting with ‘Pink Icicle’ and ‘April Tryst’ (spring bloomer) and ‘Winter Star’ and ‘Yuletide (autumn flowering).

Type: flowering shrub

Size: 8 – 12 feet tall and 6 feet wide (see pruning)

Soil: well-drained, moist, organically amended soil; maintain a mulch depth of 2-3 inches of pine bark chips or needles.

When to plant: container plants are planted from late winter (March) through early October

Exposure: full morning sunlight, protect from afternoon heat and sunlight and drying winter winds

Watering: adequately irrigate camellias during first two years when rainfall is sparse. Established camellias demonstrate good heat and drought tolerances.

Fertilizer: nourish with an acidifying fertilizer such as Miracid™, Hollytone™ or equivalent in the months of March, May and July

When to prune: prune in very late May to reduce shrub height and broaden width
In your landscape: hardy camellias bloom with large showy flowers at a time of year when few plants do. Some exhibit exceptional evergreen foliage to rival most hollies. Be forewarned: habit-forming, you will desire to plant more camellias

Winterizing Your Garden

Posted by Hugh on September 8th, 2010

Winterizing Your Garden

Garden Tools and Equipment Maintenance

Clean tools and coat with oil to prevent rust. Scrape off all dirt with a wire brush or steel wool. Store all tools off the ground in a dry spot.
Sharpen and lubricate all pruning tools.
Drain water from hoses and irrigation equipment. Disconnect all hoses and store kink-free in garage or storage building.
At final mowing run all gas out of tank and remove spark plug. Clean and oil all moving parts. A drop of oil can protect parts from rusting. Remove blade and sharpen to get ready for next spring.
Clean out garden carts, wheelbarrow and wash spreader to remove all fertilizer and pesticides.
Store all pesticides in a dry location with temperatures above 40°F.
Use up all gasoline, do not store over winter. Never use old gasoline in your equipment.

Vegetable Gardens

Remove all vegetative matter that may harbor disease pathogens and insects.
Add compost to improve garden soil for next spring.
Plough or deep till garden soil in the fall. Soil will warm up faster and excess water will drain-off rapidly, speeding up planting time.

Flower Beds

If not interested in winter seasonal interest, remove all seed heads and foliage of most perennials and wildflowers. There are some notable exceptions such as lavender, sage and artemisia. Seed heads of echinacea, rudbeckia, yarrow (achillea) and other perennials are also important food sources for many overwintering bird species.
Plant spring-flowering bulbs in the fall. Plant fall crocus and colchicum in fall.
Fall is a great time to divide and /or plant new perennials. Apply 2” of organic mulch around newly planted perennials to retain soil heat to promote root growth and prevent heaving of plants over winter’s freeze/thaw cycles.
After first frost, dig and store tender bulbs and tubers such as gladiolus, tuberous begonias, dahlias, and cannas.
Pull up dead or spent annuals and compost. Any diseases plants should be placed in the trash.
Remove all weeds in flower beds, particularly winter annuals like henbit, chickweed and annual bluegrass.

Roses

Rake up all fallen leaves around rose shrubs and dispose of properly.
Cut back roses no more than 25%, removing spent flower heads and weak spindly growth. Major pruning chores are best delayed until late winter.
Never fertilize roses from fall thru early winter.

Containers

Container grown plants are very frost sensitive. Cuttings may be collected and old plants and potting mix should be composted.
Root systems of many hardy perennials, shrubs and trees are not as hardy as the shoots and need additional protection against freeze injury.
Store empty stored ceramic and plastic containers in a dry storage building or garage to prevent breakage.

Lawn Care

Rake up leaves, woody twigs and branches. Dispose of grass clippings in the compost bin. Large leaves tend pile up and eventually smother the lawn grass.
Cut the lawn one final time around Thanksgiving
Apply a slow release winter-formulized fertilizer in late October or early November. Feeding gets your lawn off to a good start next spring.

Trees and Shrubs

No nitrogen containing fertilizers are applied in the fall, but do apply lime and/or sulfur as a soil test analysis may recommend.
Fall is a great time to plant or transplant shrubs and trees. Nurseries still have good inventories in stock and prices are greatly discounted. Container –grown trees may be planted into early winter provided they receive a 2 to 3 inches of an organic mulch
Add 2 to 3 inches of new mulch around trees, shrubs, and trees.
As a rule, pruning is delayed until late February and March. Remove dead and dying limbs anytime of year.
Protect sensitive shrubs and trees from winter’s dry winds and potential road salt injury. Constructing a vertical windbreak made from burlap or landscaper fabric. Examples include sensitive needle evergreens, azaleas, camellias and gardenias.
To prevent rabbit and rodent feeding, wrap small mesh screening around the trunks of newly-planted apple, pear, peach, plum, apricot and cherry trees.
Deer prevention strategies should be employed if applicable.

Water Garden

Stop feeding fish and remove all non-hardy plants from pond. An option is to add a heater to prevent or reduce ice buildup over the winter months.
Remove pond pump and filter. Remove any excess debris from the pond

Conservation: sow ryegrass or clover in early fall to prevent erosion and improve garden soil (as a cover crop).

Summary: accomplishing most winterizing chores make the labor of starting off the spring garden a lot easier.

Summer Care of Trees and Shrubs

Posted by Hugh on September 8th, 2010

Just because you’re on vacation doesn’t mean your trees and shrubs are. Plants, particularly those planted this year, still depend on some love and care from you.

Watering is crucial during the hot, dry summer months. If Mother Nature doesn’t supply adequate rainfall, you must. Plants should receive at least 1” of water each week, whether natural or applied by you.

During a dry period lasting three or more weeks without rainfall, you may need to supply water to your plants twice a week. New transplants of trees and shrubs are particularly in harm’s way. During a rainy period, no water is needed.

A summer mulch is also a good way to conserve soil moisture, keep weeds down, and cool soil temperatures. All of this is a great way to help your plants make it through the summer.

Hold off fertilizing until mid-winter (February through March). At that time, apply a 10-10-10 or fertilizer for shrubs and trees.

Twice a month watering of evergreen plants into the fall and winter months may be needed if the dry weather continues.

Failure of Shrubs and Trees to Bloom

Posted by Hugh on September 8th, 2010

It is usually quite difficult to determine why a shrub or tree fails to bloom. Most often the problem is the plant’s health, related to weather or environmental factors. Sometimes, the gardener has grown the plant poorly. Here are the seven leading causes:

High much nitrogen? The nitrogen to carbohydrate ratio (C:N) is a common fault. Too much nitrogen fertilizer encourages vegetative growth at the expense of flower production. Withholding nitrogen (particularly lawn fertilizer) application prior to bloom is the remedy. Root pruning around the shrub or tree’s drip line maybe another alternative.
Soil nutrition? A deficiency of phosphorus in the soil will inhibit blooming. To correct, dig a shallow trench around the plant. For each 3 feet of soil removed from the ditch, thoroughly mix a cupful of super-phosphate, or 2 cups of bonemeal, or a cupful of 0-20-20 into the dug soil and return to the soil.
Sun or shade? Shrubs and trees, which prefer a sunny location, fail to bloom in shade. Shade loving plants bloom more heavily in sunny locations, but plant health may decline afterward.
Plant spacing? Competition among nearby tree and shrub roots for moisture and nutrients may discourage blooming. Do not crowd plants.
Planting depth? If trees, shrubs or perennials are planted too deeply, the roots may lack water and oxygen.
Time of pruning? Pruning at the wrong time of the year may deter flower bud initiation or remove flower buds already formed. As a general rule, prune summer flowering trees and shrubs in late winter and spring bloomers within 4 weeks after petals fall.
Root sucker and shoot sprout removal? Vigorous root sucker and sprout growths around the plant base or densely thick on branches reduce flower bud initiation. Prune off sucker and sprout growths anytime that you see them.

Fall Blooming Perennials

Posted by Hugh on September 8th, 2010

Photo: Fall anemone ‘Honorine Jobert’

The end of summer does not mean that other perennials aren’t beginning their blooming season. Three fall flowering perennials- reblooming daylilies, remontant iris, and fall anemones- thrive here in the Southern Appalachian (USDA zones 6 and 7).

Early fall is a great time to again enjoy a lovely bed of re-blooming daylilies (Hemerocallus spp.). ‘Stella D’Oro’ (golden yellow), the most popular variety for the past quarter of the century, was recently dethroned by ‘Happy Returns’ (light yellow). ‘Pardon Me’ (red) is another re-blooming favorite. Inter-planting daffodils, tulips or hyacinths among the daylily clumps extends your floral calendar another month or two.

Remontant iris (Iris spp.) re-bloom a second time from August through November. The trick to re-blooming daylilies and irises is to provide some relief from summer drought stress. Weekly deep watering is certain guarantee of repeat fall bloom.

Fall anemones (Anemone x hybrida) are available in many colorful varieties, starting with an old favorite and garden performer ‘Honorine Jobert’ (2-3 ” single white blooms), ‘Queen Charlotte’ (3″ semi-double pink), ‘September Charm’ (3″ single rose-pink), and ‘Whirlwind’ (4″ semi-double white).

Do not grow fall anemones in direct full day sun. Plants prefer a partial sun to partial shady spot. Caution: plant in spring thru mid-summer to permit adequate time to establish their roots. Anemones perennialize easily when planted in richly composted, well-drained garden soil.