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

Care of African Violets

Posted by Hugh on December 8th, 2017

African violets at Garden Center

African violet gift plant

African violets (Saintpaulia ionantha) or AVs are among the easiest flowering house plant to grow. They need indirect moderate to bright lighting and moist well-drained potting soil. Grow plants in plastic pots and not in clay (terra cotta). AVs should be repotted annually.

Here are some additional cultural tips:

Room temperatures: AVs thrive at room temperatures between 65 to 80 °F. Set plants away from cold drafty windows.

Watering: Keep soil moist, but permit soil to dry out 4-5 days between waterings. Water plants mostly from the bottom with room temperature water. Allow plant to absorb water from a saucer or tray for 20-30 minutes and drain off the extra. Cold water straight from the tap can cause leaf spotting and may contain harmful chlorides or fluorides. Do not allow plants to sit in water too long as AVs are susceptible to root rot diseases.

Plant nutrition: Feed with water soluble fertilizers such as Miracle-Gro® or Optimara® African Violet Food at one-half the package directions; feed the dilute solution twice as often from mid-February thru September. Cut back feeding to once monthly during the fall and winter months (October thru early February). If tap water contains fluoridated or chlorinated, store water in an open top container overnight to allow the chloride or fluoride gas to escape.

Lighting: Indirect sunlight or artificial lighting is best. Plants stop flowering and leaves become chlorotic (yellow) when they don’t receive enough light. Leaves and stems also stretch out and weaken. Too much sunlight can cause leaves to sunburn, and leaf stems (petioles) to droop downward; variegated leaf varieties may turn fully green. If light source is from a nearby window, rotate pots one-quarter turn weekly, perhaps after you’ve watered.

Many hobbiests grow their AV collection under special “grow lights” for 10-12 hours a day. Grow lights are generally mounted 18 to 20 inches above plants or 10 to 12 inches above small cuttings or miniature varieties. Connect lights to a timer, so they go on and off even when you are away.

Humidity/Air Circulation: Group plants close together but do not crowd them. Give violets enough room to grow and to maintain sufficient air circulation in order to prevent the growth of potentially harmful Botrytis and Powdery Mildew diseases. A room humidifier will also help over the winter and summer months when heat and air systems are drying out the room environment.

New: The Bushel and Berry Collection Of Patio Fruits

Posted by Hugh on December 4th, 2017

Bushel and Berry™ Collection Raspberry Shortcake

Back in late 2016 Star® Roses and Plants* purchased the company formerly known as BrazelBerries®. In 2017 they have rebranded the plant offerings into the new Bushel and Berry™ Collection. Beside the old favorites, a new collection of edible berry plants are available at participating garden centers nationwide.

I have successfully grown two varieties on the sunny portion of my deck here in northeast TN (USDA hardiness zone 6-b). The spring purchased plants bloomed and produce fruits which were delicious. The Bushel and Berry Collection are easy-to-grow and ask for very little maintenance other than watering and fertilizing. Disease and insects did not trouble me my first year. I can’t promise that this will continue in future years. My plants were covered with cheese cloth as fruits began ripening for bird-proofing.

According to Layci Gragnani, program manager for Bushel and Berry, “the collection has a new look reminiscent of the biodegradable berry baskets found at farmer’s markets.” Currently, The Bushel and Berry collection includes seven varieties:

Raspberry Shortcake® – thornless dwarf raspberry

Peach Sorbet® blueberry – delicious fruits plus red fall leaf color

Jelly Bean® blueberry –dwarf plant with attractive red fall leaf color

Blueberry Glaze® – small dark berries and red fall leaf color.

Pink Icing™ blueberry – yummy fruits in summer and fall foliage

Perpetua® blueberry – double cropping (2 harvest times)

Baby Cakes™ – thornless dwarf blackberry.

Three growing tips (from me):

Repot in late winter to a slightly larger decorative pot and remove (prune) off old canes and any dead shoots.
Fertilize with a water soluble products like Espoma™ or Miracle-Gro™ bi-monthly from March through August
Place fine mesh netting over pot(s) as fruits begin to ripen.

*Star® Roses and Plants also markets the Knock Out® Family of Roses as well as Drift® Roses.

Live Cut Foliage And Berries For Home Holiday Decorations

Posted by Hugh on December 1st, 2017

Wreath of Southern Magnolia et al.

Many conifers make great cuts for indoor and outdoor Christmas decorations. Foliage choices: Eastern red cedar and many other junipers, white pine, Norway spruce, Colorado spruce, Balsam fir, Canadian hemlock, Arizona cypress (and cultivars ‘Carolina Sapphire’ and ‘Blue Ice’), and False cypresses (C. pisifera). Needle retention varies among species. For example, Norway spruce and balsam fir often start shedding their needles within three weeks after they are pruned from the tree.

Wreath of Evergreen Boughs, Dried Hydrangea Flower and Willow

Additional foliage choices: English ivy (Hedera helix), heath (Erica), heather (Calluna), Sweetbox (Sarcococca), Southern magnolia (M. grandifolia), sweetbay magnolia (M. virginiana), Schlip laurel (Prunus laurocerasus), Alexandrian Laurel (Danae), Rhododendron, Mountain laurel (Kalmia), daphne, bayberry (Myrica), Anise shrub (Illicium), Leatherleaf mahonia (Mahonia bealei), Boxwood (Buxus), Distylium, and numerous of evergreen hollies (Ilex) including American holly, ‘Nellie R. Stevens’ and ‘Foster’ hollies to create beautiful holiday outdoor displays and table arrangements.

Include on this list Unique deciduous cut stems such as Contorted willow, Contorted filbert (Harry Lauder’s Walking stick), Contorted mulberry (Morus bombycis ‘Unyru’) and M. alba ‘Nuclear Blast’).

Cut dried flowers from various hydrangea species (Hydrangea spp.) and plumes from several grass species.

Showy Fruits and Seeds: Cones from evergreen trees and brightly colored fruits from shrubbery such as Crabapple (Malus), Viburnums, Cotoneasters, Beautyberry (Callicarpa spp.), and Hollies, both evergreen and deciduous forms.

Don’t forget to purchase some tools and accessories: sharp cutting shears, spools of wire and cord, ribbons

Where to purchase greenery cuts:

local Christmas tree farms and city sales lots
on-line sources are plentiful; start shopping for greenery and accessories in early November rather than later.
many local greenhouses and garden centers offer a good choice of greenery and accessories
local holly and evergreen nurseries (note: often they are noted listed on line. Check with your local Extension office for a list)

Garland of Greenery at Biltmore Estates, Asheville, NC

Protect Young Trees and Shrubs From Voles, Rabbits And Other Critters

Posted by Hugh on November 27th, 2017

Young deciduous azalea protected by hardware cloth

Rabbits, chipmunks, and voles (field mice) need a home for the winter. They often choose to nestle up near newly planted trees and shrubs and gnaw on their sweet sapwood, girdling the trunk and essentially killing the tree. Fruit-bearing plants often damaged by critters over their first 1-2 winters include: apple, pear, peach, redbud, blueberry, and cane fruits. Young landscape plants such as crabapple, serviceberry, rose, and azalea may also be damaged. Critters may also nibble off the flower buds of spring blooming shrubs.

Deter rabbits by loosely wrapping chicken wire around desirable plants. Coil several strands so critters can’t nibble through the wire. Prior to the start of winter, clear away all weedy brush and debris where they may nest or hide. Pull away all mulch from young newly planted (1-2 year old planted) fruit trees.

The fencing or mechanical barrier should stand 24 to 36 inches high to deter rabbits from climbing over after a heavy snow. Bury the bottom 2-3 inches below the ground to firmly anchor fencing or other mechanical barrier to prevent rabbits from crawling under. Tree wraps made from kraft paper or spiral tree guards can protect tree trunks from critter feeding and also to insulate cold sensitive species against sunscald and freeze damage. Tree guards and wraps should be removed in the early days of spring.

Traps and repellents are other management tools. Repellents should be applied multiple times over the fall – winter period.

Euonymus ‘Moonshadow’ – A Ground Cover For All Seasons

Posted by Hugh on November 24th, 2017

‘Moonshadow’ euonymus

Many so-called shade perennials such as hostas, astilbes, brunneras, and coralbells (Heuchera spp.) actually excel in areas that are bathe mostly morning sunlight. In these areas ‘Moonshadow’ euonymus (Euonymus fortunei ‘Moonshadow’) makes a great companion shrub with these perennials (USDA hardiness zones 4-8). Moonshadow has become a favorite ground cover euonymus of mine.

‘Moonshadow’ euonymus is a low growing evergreen shrub displaying shiny yellow leaves with dark green edges. Its attractive variegated evergreen foliage makes it a stand out for almost any landscape situation. Leaves take on a pink hue which adds to its 4-season landscape interest.

This low ground cover is almost mat-like @ 1 to 2 feet high and 4-5 feet wide. It stays low and compact. Similar euonymus varieties like ‘Emerald and Gold’ and ‘Emerald Gaiety’ tend to outgrow what the plant tag information describes about it. Other cultivars grow 24 -30 inches tall at maturity with a spread of 5 feet or more. Foliage is a muted yellow with an attractive – dark olive green blotch. On a rare occasion a branch may reverted to all-green and should be cut out. Mostly, it holds its variegation well. Very slow to grow from rooted divisions.

It tolerates most soils except wet soggy sites and grows in full sun to partial shade. It is very adaptable to both dry and moist locations, and should do just fine under typical garden conditions. It is not particular as to soil type or pH. It is highly tolerant of urban pollution and will even thrive in inner city environments.

‘Moonshadow’ has a moderate growth rate. Mass as a low growing groundcover under shrubs or trees or in front of a border. Line along drives and walkways or a low hedge. Add a snap of color in containers by using this brightly colored trailer as a spiller to trail over the pot edges.

It’s a euonymus, so the potential for scale is there. It can be pruned at any time.

The Glorious Katsura Tree

Posted by Hugh on November 20th, 2017

Late summer foliage

Two Katsura trees at Chanticleer Gardens in Wayne, PA

Katsura Tree (Cercidophyllum japonicum) is a medium to large tree indigenous to China, Korea and Japan (USDA hardiness zones 4-8). Fossil imprints indicate that Katsura Tree has existed over 1.8 million years and flourished throughout Asia and North America. Katsura’s genus name Cercidophyllum translates to “leaf (phyllum) like a red bud (Cercis)”.

A mature tree can reach a height of 40-60 feet and spread of 35-60 feet. The tree may be single or multi-trunked. Summer heart-shaped leaves are light green and mimic that of redbuds in appearance. Redbud produces larger heart-shaped leaves with entire (toothless) leaf margins.

Katsura Tree is dioecious species, e.g. male and female flowers are on different trees. Male and female trees differ in form. Male trees tend to grow more upright and tall, female trees are wider in appearance. Flowers are small and most people don’t notice when the tree is blooming in late March. In autumn, the entire tree is aglow in yellow and there a whiff of cinnamon or caramelized sugar in the air.

Katsura Tree is best grown in rich, moist, well-drained soils and in full sun to partial shade. It prefers a moderately acidic to slightly alkaline soil pH. This beautiful ornamental tree may partially sheds some leaves seasonally, particularly a young tree, as a response to hot dry weather. Katsura Tree produce few viable seeds.

The branch and trunk wood of a mature tree is a major asset along with the tree’s architectural form in the winter landscape. As the tree ages, the trunk may take on a shaggy appearance. Katsura Tree roots are shallow; thus a lawn may be difficult to maintain. Roots of older trees may raise sidewalks.

Don’t expect to find Katsura Tree and cultivars thereof at local garden centers. However, it can be offered by online nurseries.

Significant Cultivars:

‘Rotfuchs’ (“RED FOX”) produces new leaves emerge deep burgundy-purple in spring, later turning blue green in summer.

‘Aureum’ produces that leaves that emerge purplish in spring and mature to bright yellow by summer.

‘Pendula’ are graceful weeping forms with pendulous branching. ‘Tidal Wave’ and ‘Amazing Grace’ are other weeping forms.

Amur Cork Tree

Posted by Hugh on November 16th, 2017

Amur Corktree at Biltmore Estate, Asheville, NC

Summer foliage of Amur corktree

Amur corktree (Phellodendron amurense) is native to Northern China, Korea and Japan (USDA hardiness zones 4-9). Amur corktree is a fast growing, upright branched tree that makes an excellent yard or shade tree. Corktree grows in a wide range soils, and tolerates soil pH between 5.0 to 8.2. It does best in moist, well-drained soils, but it can stand dryer soils and conditions. It is drought tolerant and does well in areas of high heat and cold.

Amur corktree was a good choice for use on large properties such as golf courses, industrial sites, and urban parks where its wide shallow rootsystem has room to grow. Roots rarely interfere with underground utility lines as will sycamores (Platanus) or willows (Salix). Use as a street tree is questionable as corktree does not prosper in compact droughty soils. Its pinnately compound foliage is also tolerant of many air-borne pollutants common in urban environments.

The spreading branches of corktree cast lots of shade. This medium sized tree will reach heights of 30 to 50 feet, with its branch spread similar to its height. The tree is often seen multi-trunked. A second corktree species, Lavalle corktree (P. lavallei), is almost identical in all traits except branching that tends to be more upright.

Corktree is dioecious, e.g., a female tree produces inconspicuous flowers that give rise to sweet drupe fruits. As its common name suggests, Amur corktree exhibits distinctive porous (spongy) bark texture. Leaves, when crushed, emit a variety of scents that some described as “citrusy”.

Cultivars:

‘His Majesty’ (P. sachalinense x P. amurense) – male, fruitless, broadly vase-shaped, yellow fall color),

Eye Stopper ™ (P. lavallei ‘Long Necker’) – selected for bright yellow fall color; slightly less corky bark

Macho® (P. amuerense) – vigorous male, fruitless, broadly vase- shaped, tree.

Shademaster® (‘PNI 4551’) – male fruitless with glossy foliage,

Superfection™ (‘Supzam’) – male fruitless, upright-uniform branching habit

Important Note: Amur corktree is considered invasive in parts of the northeastern U.S. where it may outcompete native species.

The Great Little Bluestems*

Posted by Hugh on November 12th, 2017

Little Bluestem Fall Color at NC Arboretum, Asheville, NC

Summer foliage

Little Bluestem (Schizachyrium scoparium) is an attractive prairie grass native in southeastern or southwestern areas of the U.S. It is exceptionally hardy (USDA hardiness zones 3-9). Heights of the species (including inflorescences) vary from 2 – 2.5 feet tall and many cultivars grow 3-4 feet tall. Its late summer to fall foliage is a kaleidoscope of pastel colors and later coppery tones.

Stems of Little Bluestem stand rigidly upright and do not lay down during the winter, particularly after multiple snow falls, . The species is slightly variable in foliage features and the hairiness of its floral racemes. Over the years plant breeders have developed cultivars exhibiting more intense reddish foliage in autumn (see below).

Little Bluestem is tough and adaptable, tolerant of wide fluctuations in soil moisture levels through the seasons. It grows in both acidic and alkaline soils. A new seeding establishes quickly on steep banks, slopes, and restoration plantings as well as in meadows, prairies, and mixed plantings. Little Bluestem also provides food and shelter for wildlife, including birds and butterflies.

Little Bluestem performs at its best in full sun. In early spring cut back an established seeding for appearance and to allow new leaf blades to fill in. Feed a slow-release fertilizer such as Nutrikote™, Osmocote™, or equivalent. Shade, too high fertility, and too much moisture will result in floppy growth and poor seasonal color.

Little Bluestems Cultivars

‘Blaze’ grows in an upright shape and sports blue green summer foliage. Fiery fall colors are a mix of reds and purples, along with hints of orange and pink.

‘Carousel’ (PP20948) has a low broader shanc and grows strongly upright through the winter.

Blue Heaven® (‘MinnblueA’) is a robust, tall with bright variation. It starts out with light blue foliage in the spring and deep pink, later and burgundy red hues from late summer to fall.

‘Prairie Blues’ offers improved durable blue-gray fall color.

‘Smoke Signal’ offers narrow, refined, blue-green early summer foliage with deep red tones in late summer, and deeper red-purple in fall.

‘Standing Ovation’ (PP25202) has sturdy, thick stems that stands up to high winds and pounding rain; fall colors are mix of stunning reds and oranges.

‘The Blues’ struts stunning blue foliage accented by red stems thru summer; fall colors are a mix of purple, orange, and shades of blue.

Special note: The scientific name of Little Bluestem was formerly Andropogon scoparius.

*Some information in this blog furnished by Shannon Currey, Hoffman Nursery (wholesale grower) in Rougemont, NC near Greensboro.

Lantanas For Sunny Gardens

Posted by Hugh on November 8th, 2017

Lovely planting of lantanas

Mixed container including lantanas + petunias + junipers

Lantanas (Lantana x) are favorite bedding plants, particularly in southern and western U.S. gardens where summers are hot and long. Lantanas are generally planted in flower gardens, but can be grown in containers, including hanging baskets. Plants bloom from late spring until the cool days of fall arrive. Some environmentalists classify them as invasive because birds feed on the abundant berries and distribute the seeds over many miles.

Lantanas like full sun and can grow upright, mounded, spreading , and even trailing depending on cultivar. Feed newly set transplants with a slow release fertilizer such as Osmocote™ or Nutrikote™. An alternative feeding program is to apply a water soluble product such as Miracle-Gro™, Peters™, or Daniels™ every 6-8 weeks from planting time up to late August. Lantanas prosper in a slightly acidic soil.

In areas with long growing seasons such as Florida, Texas or Southern California (zones 9 to 11), plants may be trained into various topiary forms, including miniature trees. Here, lantanas are dependable shrubs or perennials. In cool temperate regions potted plants may be moved to a cool protected place such as a garage or unheated sunroom to overwinter.

Flower heads are small globes of tiny florets. Cultivars come in a wide array of colors from rose pink, yellow, orange or a combination of many flowers. Popular cultivar series include Luscious®, Lucky® and Bandana®. Bandanas grow shorter, about 24-30 inches high, depending on the cultivar. Some gardeners prefer the cultivars ‘New Gold’ and ‘Miss Huff’ that produce sterile seeds and are not invasive.

Disease prevention of problems is always your best alternative. Set lantanas in well-drained soil with good air circulation around plants. Lantana may on occasion succumb to root rot or powdery mildew, particularly when summer weather is unusally wet.

Sooty mold, caused by insect feeding by aphids, mites, and whiteflies, turns leaf surfaces and stems black. Problem pests can be sprayed with several kinds of pesticides or washed off. Plants can also be troubled by tiny sap-sucking lacebugs whose damage leads to leaf drop.

Lantanas are deer resistant and the flowers are favorites of hummingbirds, bees and butterflies. Berries can be toxic to pets and humans and leaves may cause a rash for some people.

Unappreciated And Underplanted Sawtooth Oak

Posted by Hugh on November 5th, 2017

Sawtooth oak on ETSU campus in Johnson City, TN

Foliage in early fall of sawtooth oak

Sawtooth oak (Quercus acutissima) is a medium-sized deciduous oak that exhibits traits similar to both the white oak and red oak sections. Indigenous to China, Korea and Japan, sawtooth oak has naturalized in some parts of the U.S. (USDA hardiness zones (5?)6-9). Sawtooth oak grows 40-60 feet tall and wide with broad spreading branches and rounded canopy.

Leaves of sawtooth oak are frequently mistaken for chestnut (Castanea). Long (5 to 7 inches long), lance-shaped, glossy dark green leaves are chestnut-like. Leaf veins are well defined, each ending with a single bristle on the margin (leaf edge). Fall color is variable, ranging from an attractive golden brown to undistinguished pale brown. Dead leaves tend to persist through most of winter.

Long stringy, yellowish-green catkin flowers in separate (male open first) and female catkins appear in early to mid-spring before leaves emerge. Flowers are not ornamentally significant.

Sawtooth oak grows in average well-drained soil and in full sun. Fertilize in late winter with a slow release product such as Osmocote™ or Nutrikote™. The tree tolerates summer heat and humidity. Chlorotic or yellowed leaves is common in neutral to alkaline pH soils in summer. Compared to most oak species, it is moderately pest resistant.

Its corky ridged gray bark matures to a black fissured bark over the years in this long-lived oak. Sawtooth oak this medium to large oak is not planted enough. It is an exceptional shade or specimen tree in residential or park settings and is also found lining parking lots, median strips and roadways.

Acorns are oval in shape and start to form start in 10-12 years after planting. Cap covers nearly two-thirds of nut with hairy scales that are prominently reflexed. Acorns ripen in early fall and are an important wildlife food source.