Sedum ‘Lidakense’ at Kingwood Center in Mansfield, Ohio
S. rupestre ‘Angelina’
Tips for Growing Abutilon (Flowering Maple)
Posted by Hugh on November 20th, 2018
‘Ball Gown’ plants for sale at Biltmore Estates
Abutilon (Abutilon x hybridum) is a group of tender evergreen perennials (USDA hardiness zones 9-11). In USDA hardiness zones 6 thru 8, abutilon is grown outdoors from mid-spring to mid- autumn, when it is moved indoors and grown as a tropical houseplant. When moved indoors, partially cut back to fit its indoor space. In early spring prune the plant back hard.
Abutilon -flowering maple
Abutilon is known by several names including Chinese bellflower, Chinese lantern, Parlor maple, and flowering maple. It’s related to mallows and hibiscus (plant family Malvaceae). Albutilon has maple-like palmate deeply lobed leaves and bears colorful delicate looking flowers. Abutilon may flower almost non-stop in shades from white, pale yellow, orange, red, and bi-colors.
Abutilon is not too particular about soil (potting media). It should be well-drained, moist, and pH near neutral (6.2-7.2). Re-pot a container grown plant(s) into new larger containers and in new potting soil. Feed every two weeks with a dilute, water-soluble fertilizer such as Miracle-Gro™, Jack’s™, or Schultz™.
During the summer abutilon may be infested with whiteflies, spider mites, scale and mealybugs. Spray leaves and stems with water to wash pests off or spray with insecticidal soap or neem oil. Plants should be adequately spaced and keep foliage dry to prevent leaf spots and rust diseases.
Some gardeners opt to train abutilon into a tree or topiary form. Flowering maple is also great in a garden bed or a hanging basket. Butterflies and hummingbirds are attracted to their pendent bell-shaped flowers, available in many colors including yellow, orange, pink, red, and bi-colors.
Today’s flowering maples are the result of hybridizing between four species A. darwinii, A. striatum, A. pictum, and A. megapotamicum. One of the finest is ‘Biltmore Ballgown’, an heirloom variety sold by Biltmore Estate in Asheville, NC. It grows 2-4 feet high and 1-2 feet wide with showy orange-netted lantern flowers.
Abutilon is propagated by softwood cuttings. Beware: Leaf sap may cause mild dermatitis in susceptible individuals.
Fertilizing Trees And Shrubs
Posted by Hugh on November 15th, 2018
Fertilize area under tree 1.5 times the tree’s spread
Apply fertilizer in planting area under the sweetgums
Maintaining good plant nutrition is of key importance. A tree and shrub which is growing vigorously can resist infestation from most diseases and insects. Symptoms of poor nutrition: pale green or chlorotic leaves; undersized plants; slower annual growth rate; many dead or dying branch tips; increased insect/disease problems.
Trees under 10 years of age should be fertilized annually. There is little need to feed newly planted specimens and those suffering root damage from recent trenching or construction. Yard shade trees generally receive adequate fertilizing if the lawn is fed twice annually. Old established trees do not need to be fertilized every year.
High pH (alkaline) soils can result in chronic deficiencies of nutrients in some tree species, such as red maple, birch and pin oak, as well as nitrogen-deficient soils. Nitrogen (N), phosphorus (P), and potassium (K) are essential plant nutrients found in bags of fertilizers. The analysis will vary from one fertilizer manufacturer to another. Some products may be organic-based and are “slow-release”.
The fertilizer label on the package lists the exact proportions of available nutrients. For example, a bag label of 20-10-10 contains 20% N, 10% P (phosphoric acid), and 10% potassium (K) as potash. A 50 pound bag containing 20% nitrogen fertilizer (10 pounds of actual nitrogen) and also 5 pounds each of P and K.
Your soil should be tested every 4-5 years to check and correct (if necessary) a nutrient deficiency or soil pH that may be out of balance. Many land grant universities and full service garden centers offer fee-based soil testing.
General Fertilizer Program for trees and shrubs:
Here in Tennessee or Virginia, the best time to fertilize is late March or early April or in late fall once plants are dormant. In New England or Midwestern states, application time may be 2-4 weeks later. Weigh out the recommended fertilizer and distribute it evenly under the tree or around the shrub. Do not fertilize within 12 inches of the main trunk. Do not exceed rate of 3 lbs. of actual nitrogen per 1,000 square feet. Tree roots usually spread 1.5 times the diameter of the branch spread or that of the shrub width. Around mass groupings of plants, calculate the surface area around the entire planting to be fertilized (see photos above).
Information Source: Morton Arboretum in Lisle IL
Beware Of Fast Growing Trees
Posted by Hugh on November 10th, 2018
Platanus x acerifolia
Silver maple in autumn
Many property owners choose fast growing landscape trees. These large shade trees increase the value of your property. Their summer shade and wintry wind protection may reduce utility bills by 20 – 25% . Trees attract wild birds for nesting, protection, and as a food source. Some brighten up your landscape with dazzling fall color. However, we may pay a price for the fast growth.
Trees listed here are rated as fast growing. In general, most (not all) fast growing trees are weak wooded. Branches may break apart under ice or snow loads and in high winds. Their shallow roots may uplift or crack sidewalks. Do not plant fast growing species within 50 feet of your home as tree roots may penetrate foundations and septic fields. This is particularly true for silver maples, cottonwoods, poplars, and weeping willows. Some species are also susceptible to verticillium wilt, leaf anthracnose, and cankers; pests like scale and borers may be troublesome at times.
Do not assume that all listed species are troublesome. Those marked by an asterisk (*) are superior trees and are highly recommended. All species are rated hardy in USDA zones 5-8. Better cultivars are listed for a few species.
Fifteen Large Fast Growing trees (25 feet or more high after 10 years):
Box elder (Acer negundo)
*Silver Maple (Acer saccharinum) ‘Silver Queen’
Tree of Heaven (Ailanthus altissima) – rated an invasive species in some states
Eastern cottonwood
Common hackberry (Celtis occidentalis)
*Tulip poplar, tulip tree (Liriodendron tulipifera)
Empress tree (Paulownia tomentosum) – rated an invasive species in some states
*London Planetree (Platanus x acerfolia)
Sycamore, planetree (Platanus occidentalis)
Eastern Cottonwood (Populus deltoides)
Lombardy poplar (Populus nigra ‘Italica’)
Quaking aspen (Populus tremuloides)
Weeping Willow (Salix babylonica)
*Basswood, American linden (Tilia americana)
*American Elm (Ulmus americana) ‘Washington’, Princeton’, ‘Jefferson’
Siberian elm (Ulmus pumilo) -rated an invasive species in some states
Dieback Shrubs
Posted by Hugh on November 5th, 2018
Buddleia
Dieback shrubs are a group of hardy landscape shrubs that emerge and grow vigorously from mid-spring through early summer. They bloom reliably from late summer into early fall. Plants are near the edge of their hardiness range, and often die back to the ground in the winter. They act more like herbaceous perennials. The above-ground shoots are not dependably winter hardy.
Stated another way, a dieback shrub is a woody deciduous species that grows one full plant zone lower (colder) as a perennial. A zone 7 hardy woody shrub performs more like a herbaceous perennial in zone 6. It dies back to the ground in winter and re-grows and blooms the following year. Prune the shrub back in early spring before the bud break. Their colorful flowers attract bees, butterflies, and other pollinators, and are mostly deer resistant.
Four Reliable Dieback Shrubs:
- Butterfly bush (Buddleia x davidii) is cold hardy to zone 5 which makes it suitable for most gardeners in the United States. These shrubs generally grow 2-3 feet tall, usually as wide and tall. They’re tough plants that can tolerate lean and alkaline soils. Plants perform at their best in average well-drained soil with a pH range of 5.5 to 8.5.
- Bluebeard shrub (Caryopteris spp.), also called blue mist or blue spirea, produces gray-green foliage and bright blue flowers in early summer through fall (USDA hardiness zones 5-9). Leading varieties include Petit Bleu® (rich blue blooms), ‘Worcester Gold’, and ‘Longwood Blue’.
- Chaste tree (Vitex agnus-castus) include short growing varieties like Blue Puffball™ (3-4 feet tall and wide in zones 6-9) and Blue Diddley® (3-6 feet tall in zones 5-9).
- Crape myrtle thrives in the southeast U.S. (zones 6-10), but are at risk in colder northern areas. Grow them as perennials in full sun and average well-drained soils. Select the hardiest forms from the U.S. National Arboretum. I recommend these 4 varieties such as ‘Natchez’, ‘Muskogee’, ‘Acoma’, and ‘Osage’ to try in zones 5b -6a as herbaceous perennials.
Fall – Winter Pruning Dos and Don’ts
Posted by Hugh on October 30th, 2018
Bad cuts (sap leakage in winter)
Hand tools for pruning
Pruning is a chore that you don’t need to put off until spring. Many trees and shrubs may be pruned this autumn. However, NOT all landscape trees and shrubs are pruned. Here are some pruning guidelines to follow:
WAIT to prune spring flowering deciduous shrubs such as Forsythia, Lilac, Bridal Wreath & Vanhoutte Spireas, Quince, Viburnums, Fothergilla, Weigela, Deutzias, and some others. Add some evergreen flowering shrubs including all azaleas (both evergreen and deciduous) and rhododendrons, Japanese andromeda (Pieris japonica), Mountain laurel (Kalmia), Daphne, and Mahonia. Wait 3-4 weeks after spring flowering to prune all the above shrubs plus a few others not listed.
DO PRUNE NOW: Summer flower shrubs should be pruned now while they are dormant to manage size, shape, balance, and uniformity prior to spring growth. These include Summer Spireas, Panicle hydrangeas (H. paniculata) & Smooth hydrangeas (H. arborescens), Rose of Sharon (Hibiscus syriacus), Bluemist (Caryopteris), Butterfly bush (Buddleia), Potentilla (cinquefoil), Summersweet (Clethra). and others.
Hold off pruning Big Leaf Hydrangeas (H. macrophylla). They bloom both on old last year’s wood and on new wood. Wait until spring to determine if winter climes have injured the old wood. After harsh winters Big Leaf hydrangeas may be cutback to 3-5 feet and will bloom mostly on new wood later in summer.
ROSES: Pruning varies according to the species of roses. Hybrid Tea, Grandiflora and Floribunda types can be lightly prune back by 25 to 30%. In the early days of spring, prune to the desired height and width, remove diseased or broken canes, and thin out the interior of the bush. Shrub roses including Knock Out™, Home Run™, and Carefree™ series are pruned down to 18-36″ in height. Shorter types like OsoEasy™ and Flower Carpet™ are pruned to 12-18 inches in height.
Don’t Prune Crape myrtles until late winter
CRAPE MYRTLES: Predicting winter cold is foolhardy, so hold off until spring. In general, crape myrtles need for little annual pruning other than removing dead, diseased, weak wood, and the old seed heads.
DECIDUOUS SHADE TREES: Prune them now before or after leaf drop. For young, newly developing trees, thin out excess branches, remove lower limb, and shape of the tree’s upper crown.
SPRING FLOWERING TREES: Wait 3-4 weeks until after spring flowering to prune, mostly for appearance. Remove dead, diseased, and weak branches and twigs.
Special note: Maples (Acer spp.), Birches (Betula spp.), Yellowwood (Cladrastus), and Dogwoods (Cornus) exhibit a high sap pressure and often bleed when pruned in late winter and early spring. If you prune them now, they will “bleed” sap.
Stoloniferous Dogwoods Jazz Up The Winter Landscape
Posted by Hugh on October 25th, 2018
Redtwig Dogwood Brightens Up The Winter Garden
White fruits in September
Red osier dogwood (Cornus sericea) is a medium-sized, deciduous shrub native to much of the Northern and Western United States (USDA hardiness zones 2-7). Without question these shrubs standout in winter by their colorful stems (see pruning recommendations below). Cut branches are an added plus for indoor arrangements. The yellow-twig form (C. sericea ‘Flaviramea’) is also available.
Leaves are oblong-lanceolate (up to 5 inches long), oppositely arranged with 5-7 pairs of lateral veins, and entire margins. Species may grow up to 10 feet tall and spread voraciously by underground stolons to form large clumps. One landscape idea is to mix red and yellow–twig dogwoods together for a winter color blast. Osier dogwoods grow well in very large containers, but quickly outgrow their pot space in 2-3 years.
These stoloniferous dogwoods bloom in mid-spring (in Tennessee). The terminal creamy white (cyme) flowers measure 1.5 to 2.0 inches across and white berries follow in late summer.
Plant shrubs in full sun (in northern areas) and in partial shade (in zone 7) and average soil. Fertilize in early spring before buds break and irrigate during long dry summer spells. Shrubs establish quickly and are very drought tolerant after one year. Many cultivars are available, and are highly variable in leaf and stem color. This shrub dogwood may be confused with C. amomum which has a similar red bark, but C. amomum has blue fruits and brown pith.
Arctic Fire® is a non-suckering compact form with dark red winter stems. It grows 4-5 feet tall and 4-5 feet wide. It puts on a spectacular show in the wintert. Most varieties of stoloniferous dogwoods grow 8 to 10 feet, making Arctic Fire a great breakthrough for smaller gardens or residential landscapes.
Stoloniferous dogwoods are disease and insect resistant and deer generally overlook them. They make great landscape additions; utilize them in perennial or shrub borders, masses and groupings, container gardens and winter gardens.
Pruning tip: cut 2-3 year old shoots back to the ground each spring immediately after flowering to ensure a good display of the winter branches.
“No Dig” Planting Of Tulips
Posted by Hugh on October 20th, 2018
Mixed planting of Daffodils and Tulips
‘Pink Perfection’ tulips planted by “No Dig” method
Digging lots of holes to plant 25 0r 50 tulip bulbs is a backbreaking chore. It doesn’t have to be that way. More than a decade ago, plant researchers at Cornell University in Ithaca, N.Y., developed a planting method called “top-planting”. It eliminates all the digging and the tulips come back and bloom well for several years.
Top-planting, also called “drop and cover,” requires a lot less effort. I call it “No Dig Bulb Planting” and is a lot simpler:
- Till the planting area 3 to 4 inches deep with a roto-tiller.
- Plant in a site with full sun and good soil drainage.
- Spread bulb fertilizer and lightly till in the fertilizer (optional).
- Set the bulbs on top of the tilled area (no need to press the bulb into the ground).
- Cover with 2 to 4 inches of composted mulch or aged compost.
- No Dig works as well for daffodils as tulips.
Do not over-mulch. Adding more mulch may result in less blooms. Any good garden compost or double ground bark mulch should work. Brent Heath, co-owner of Brent and Becky’s Bulbs in Gloucester, VA recommends adding two inches of mulch in the fall.
Bulb Spacing: Tulip (or daffodil) bulbs that measure 2 inch wide bulbs should be spaced 3 times the bulb size or 6 inches apart. That’s 4 bulbs per square foot.
Tulip varieties that perennialize well are recommended, “particularly Darwin hybrids” according to Brent Heath. Bulbs will re-grow and re-bloom for several years after planting. Many gardeners may opt to inter-plant bulb plantings with summer flowering annuals, perennials, and vegetables.
Caveat: dormant tulips and daffodils like to spend their summers in dry soil. Too much irrigation during the summer months may rot the sleeping bulbs.
Gardeners can enjoy masses of tulips without digging a hole for each bulb.
Overwintering Caladium Tubers
Posted by Hugh on October 15th, 2018
Dr. Mary Lewnes Albrecht, retired dean of the Herbert College of Agriculture at the University of Tennessee, offers her recipe for overwintering caladiums. For many years Dr. Albrecht has been saving several heirloom varieties by this procedure:
Caladium plants dug and in trays ready for trimming
#1. Plants start to go dormant in late September through October (zone 7a Tennessee) and earlier if summer weather has been dry. Signs of dormancy: foliage begins to fade, fewer new leaves emerge, and planting looks thinner. It’s time to dig.
# 2. Dig and knock as much soil off the tubers as possible. Trim the roots to about an inch in length and clip back shoots to about 3 to 4 inches in
Single tuber pre-trimming the roots
length. Collect caladium tubers in cardboard, wooden or plastic trays. Tubers are cured when the roots and leaf bases easily come off, leaving the dormant buds behind on the tubers (usually after a week or two).
Alternative method: spread the dug tubers out on a tarp on the garage floor and let them cure.
# 3. After curing, sort tubers by size which may vary from one year to the next. Lots of consistent rainfall and hot temperatures will yield large tubers. Caladiums are tropical and thrive in summer heat and soil moisture.
Caladiums – single layer of tubers curing
# 4. Store dry tubers in open low trays. Do not stack them in deep layers. Allow good air movement around the tubers for dryness. A well-insulated garage in the 40 to 50 °F range is ideal.
Credit: photos provided by Mary L. Albrecht
Umbrella Pine—A Conifer Collector’s Dream Plant
Posted by Hugh on October 10th, 2018
Umbrella Pine at NC Arboretum in Asheville, NC
Golden Needle Form
Japanese Umbrella Pine (Sciadopitys verticillata) is an evergreen (USDA hardiness zones 5b -9). It is not actually a pine. Historically, umbrella pines date back to the dinosaur age. This mid-sized landscape tree displays several fine attributes: shiny leaves are arranged in whorls like the spokes of an umbrella; peeling, reddish brown bark and a conical habit.
To conifer collectors, umbrella pine is the ultimate prize to add to a private collection. A young nursery produced tree may require training to develop a central leader. Dwarf cultivars (see below) grow slowly, only 4-5 inches yearly.
Umbrella Pine prefers a moist, organically rich, well-drained, moderately acidic soil. Feed with a slow release organic fertilizer in early spring. Maintain a 2-3 inches layer of an organic mulch around the tree base. In the mid-South (zones 6 -7), the tree prefers one-half to full-day sunlight. Further south, morning sunlight is preferred. Pruning needs are rare, mostly to maintain the tree’s pyramidal form and to remove a broken limb or two in late winter. Disease and insect problems are rare.
In its early years, umbrella pine is a slow grower. Eventually, it reaches 30 to 40 ft. in height and 20 ft. in spread. Historic tree specimens may attain 70 or more feet in height. This unique conifer possesses stiff needles arranged in whorls resembling an upside-down umbrella. Branches can withstand heavy snow and ice loads.
The Umbrella Pine is an evergreen prized for its striking foliage and superior pyramidal form. Needles rarely go off color in winter. Select forms are available at specialty conifer nurseries.
‘Gruene Kugel’ – compact form from Germany. Rounded in shape when young, developing slowly into a small compact tree with glossy deep green foliage year-round.
‘Joe Kozey’ grows tall and exceptionally narrow at 20 feet high and only 6 feet wide; slow-growing, spire-like habit.
‘Picola’ – broad growing, 2 inch long dark green needles; ultra-dwarf selection 16- 20 inches tall after 10 years; rock garden plant.
‘Mitsch Select’ – a dense multi-stemmed shrub form with loose pyramidal habit and forest green needles.
‘Picola’– exceptional slow growing pyramidal form with dark-green foliage.
