Thursday, September 30, 2010

Fall Planting Deadline for Pansies and Violas

To grow pansies successfully, follow this four- step program. Start with: 1. Purchasing healthy plants, 2. Planting by mid-October or earlier, 3. Watering in the fall and winter as needed, and 4. Fertilizing monthly through the winter and spring months.

Shop for vigorous dark green plants at local greenhouses and garden centers. Closely inspect for lots of white growing roots. Don’t buy short or spindly seedlings or those with yellowing leaves. Purchase sturdy 1801 plants (18 - 3 ½” plant cells per tray) or larger pots. Small pansies tend to be more disease susceptible. To avoid deadly root rot diseases in garden soils, move pansy/viola beds every three years.

Over much of the Southern Appalachian region (USDA zones 6-7), the completion date for planting pansies and violas is October 15th. Back up a week or two earlier if planting in gardens at higher elevations. An earlier fall planting date allows plants adequate time to root down into the warm autumn soil. Deeply rooted plants bloom heavier through the fall and winter seasons.

Large sized plants start off quickly and fall-winter flowering is better. Deeply rooted pansies and violas provide better anchorage, which prevents a chance of winter freeze heaving. Once soil temperatures drop below 45°F, plant growth slows and flower numbers decline.

There are many series of pansies and violas to choose in colors ranging from white, yellow, pink, red, and purple shades. Color patterns may be clear, blotched or picotee. Four popular pansy series are Delta®, Matrix®, Panola®, and Majestic Giant ll™. Among the popular viola series are Sorbet®, Rocky™, Penny™ and Velour™.

Prepare the garden bed or containers prior to planting. Pansies should be planted in well-drained, organically rich garden soil or container media mix. An acidic soil pH ranging between 5.2 - 5.8 avoids natural deficiencies in iron and manganese. Adding lime to pansy beds is usually unnecessary unless recommended after a soil test. Pansies thrive in full sun to partial shade. Plants grow more compact and bloom heaviest in full sun.

Monday, September 27, 2010

Franklinia - Native Tree Lost in the Wild

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.

Saturday, September 25, 2010

Substitute Dwarf Cryptomeria for Yews and Japanese Holly

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.

Wednesday, September 22, 2010

Truly, Fall Is For Planting

Photo: Fall displays have arrived at area garden centers with this lovely bin of gourds

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

Some good deciduous choices are red maple, green ash, tulip poplar, sweetgum, willow oak, and basswood. Garden centers push to reduce store inventories, saving you 30%-50% off the list price. I offer these six basic landscape planting tips:

1. Plant only deciduous trees in the front of your home, and evergreen trees (pines, hollies, hemlock, etc.) elsewhere
2. Dig a hole three times wider and shallow enough to accomodate the diameter of the root ball
3. Plant shallow, barely covering the root ball and add no soil amendments
4. Apply three inches of an organic mulch (wood chips, pine straw or compost) over the surface
width of the planting hole and do not pile mulch up against the trunk
5. Slowly pour a minimum of 10 gallons of water to each tree after planting
6. Do not fertilize fall-planted trees and shrubs until late February or March.

Sunday, September 19, 2010

Ivy Geranium 'Lila Compact'

Ivy-leaf geraniums (Pelargonium peltatum) owe their name to their leaf shape. While zonal geraniums are favorites in garden beds, the vining or cascading ivy geraniums excel in hanging baskets, containers and window boxes.

Earlier this month I spotted this lavender beauty called ‘Lila Compact’ Cascade™ (photo) in downtown Asheville, NC. City grounds crews have hand-watered all plants over a 5-6 block area every morning since mid-May.

Improved modern cultivars exhibit better heat and drought tolerances than in the past. Newer cascading varieties of ivy geraniums are also more floriferous. Ivy-leaf geraniums grow best in cool climates and lots of sun. They handle 85°F summer temperatures for short stretches. In warmer areas of zone 7, place containers in partially shaded exposures. Ivy leaf geraniums don’t hold up to long periods of drought. They are planted outdoors after threats of spring frosts have passed and the soil/media has warmed up.

The single flowering types produce more blooms than the semi-double flowering varieties. Plants hold their compact form throughout the summer months. Many colorful varieties are available -- from 12” sized miniatures to the vigorous 4- 5 feet cascading types highlighted here.

Wednesday, September 15, 2010

Coppicing - Renewal Pruning for Old Rhododendrons

Photo: when rosebay rhododendron (R. maximum) gets too tall and leggy, coppice (prune back) in late September and October

Coppicing is a no-brainer form of renewal pruning. The entire shrub is lopped off to the ground to re-start from its roots next spring. For many gardeners, it's a gutsy move, but a fairly simple task. Coppicing also eliminates disease and/or insect- riddled stems and twigs without resorting to pesticides.

Timing is critical. Overgrown rhododendrons, including deciduous azaleas, hollies, pieris and mountain laurels may be coppiced from late September thru October. Coppicing invigorates old shrubs, brightens foliage color and increases fruit size.
Very important: over-grown shrubs should be well-established and healthy; old rhodies in poor health will likely not re-grow. Rhodies may be cut back severely to stumps with no leaves. Healthy plants recover quickly vegetatively, but do not flower for two, sometimes three years.
A coppiced plant sometimes re-grow so vigorously that some additional pruning will be necessary. Many new shoots (stems) will emerge; select the most straightest and most vigorous.

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

Saturday, September 11, 2010

Rooting Proliferations on Daylilies

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.

Wednesday, September 8, 2010

Fall Blooming Perennials

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.

Friday, September 3, 2010

'Sunshine Daydream' Helianthus for Mid-Summer Bloom

Sunshine Daydream (Helianthus x multiflorus ‘Sunshine Daydream’) has been blooming non-stop in my Northeast Tennessee garden for the past two months.

This double-flowering yellow false sunflower is a new introduction from North Creek Nurseries, a wholesale nursery in Landenberg, PA. Sunshine Daydream is a branch sport (mutation) of native cultivar ‘Capenoch Star’. It is a mid-summer flowering perennial.

Sturdy 5 - 6 feet tall by 2 - 4 feet wide plants support bouquets of bright yellow double flowers. The dahlia-like blooms measure 2.5 inches across. The spent flowers are seedless and do not threaten to become a weedy problem in years to come.

Sunshine Daydream performs best in full sun, preferably in moist well-drained soil. Keep plants in full vigor with monthly applications of a water-soluble fertilizer such as Miracle -Gro™ or equivalent or feed bi-monthly with 10-10-10 or equivalent.

Sunshine Daydream stands up to summer's heat and humidity. Established 1- year old plants are moderately drought tolerant. This long-lived perennial is hardy in USDA zones 4 thru 8. The summer foliage of Sunshine Daydream is remarkably resistant to powdery mildew, a fungal disease which plagues some helianthus species.