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ORNAMENTAL HORTICULTURE UPDATE

The Ornamental Horticulture Update is a weekly publication compiled by Allen Owings and edited by Rick Bogren of the LSU Ag Center.  Check back regularly for the Plant of the Week and the latest issue! 

By admin on Monday, April 07, 2014

Ornamental Plant of the Week
April 7, 2014
Little Ruby Alternanthera

Little Ruby alternanthera was named a LSU AgCenter Louisiana Super Plant in 2013. It is one of the newer varieties of alternanthera – also known as Joseph’s coat.

Little Ruby is best suited to a full-sun setting. It is a great low-maintenance landscape plant and has richly colored, dark burgundy foliage with ruby undersides.

Plants stay short all season long, reaching heights of 16-18 inches by fall. Plants are mounding – spreading out to about 20-24 inches. Pruning to shape is typically not needed. The excellent compact growth habit of this plant is another super feature because Little Ruby requires no deadheading.

Plant them about 18 inches apart for best “fill in” without being overgrown by fall. Plants usually don’t require irrigation once well-established, but they like some moisture in the soil. The Little Ruby variety works best in the landscape when planted in front of flowering annuals or perennials or along the outside edge of a color bed.

Ornamental Plant of the Week
April 14, 2014
Begonias

Dragon Wing and BabyWing begonias, along with many other series and varieties of begonias, can and should be considered for the warm-season, shady landscape. These two begonias have some of the best genetics available.

Begonias are available in many shapes, sizes and flower colors. Foliage colors include
green, bronze and red. Typically, the greener-foliaged begonias do best in or require shade while the reddish and bronze begonias tolerate some sunny areas. Rum, Brandy, Whiskey, Vodka and Gin are the varieties in the Cocktail series of begonias – a longtime favorite in the South.w.l-i-a.us 

By admin on Monday, March 17, 2014

Ornamental Plant of the Week
March 17, 2014
Louisiana Iris

Blooming from late March to early May, the Louisiana iris is a floral ambassador that has carried our state’s name all over the world.

Louisiana iris is the name used worldwide for a unique group of native iris species and their hybrids. Their extraordinary beauty and reliability in the garden have made them increasingly popular, but they still deserve more recognition and use here in their home territory. The Louisiana iris is our state’s official wildflower. Though a number of iris species are native to Louisiana, only five species – Iris brevicaulis, Iris fulva, Iris giganticaerulea, Iris hexagona and Iris nelsonii – are known as “The Louisianians.”

Only in south Louisiana do all five species occur together. They are closely related and will interbreed with each other but with no other species. The crossing, or interbreeding, of these species has resulted in the modern hybrid varieties we grow today. Their large, attractive flowers cover a broad range of colors, including many shades of blue, purple, red, yellow, pink, gold, brown, lavender, burgundy and white. Be sure to not confuse Louisiana irises with the yellow and blue flag irises. Louisiana irises are much better performers.

Ornamental Plant of the Week
March 24, 2014
Bandana Lantanas

A Louisiana Super Plant to consider for this spring is the Bandana lantana. The
relatively new Bandana series of lantanas are the most truly mounding of all the mounding-type lantanas. Bandanas reach 18 to 24 inches tall and 18 to 24 inches wide – a perfect size for many landscape settings and for container gardening.

Lantanas prefer full sun, limited irrigation and well-drained landscape beds. Space individual plants 16 to 18 inches apart when you plant them.

Other strong points of the Bandana lantanas include the wide range of flower colors available in the series. Varieties include white, lemon zest, cherry, cherry sunrise, light yellow, peach, rose, pink and red. Mixes of varieties available include lemon squeeze.

Bandanas are excellent fall-blooming lantanas. While some lantanas don’t bloom well into fall, Bandanas maintain flower color until first frost in most years.

Ornamental Plant of the Week
March 31, 2014
Cat Whiskers

Most folks do not know about cat whiskers (Orthosiphon stamineus). This is a great tropical plant that is very well adapted to the southeastern United States. It is sold at many retail garden centers in Louisiana but is somewhat underused. It is a great plant to attract bees, butterflies and hummingbirds. Plants prefer full sun, but some light afternoon shade is also OK. Flowers are long spikes resembling cat whiskers. They appear late spring and will last until killing frost. Flower colors are white and lavender. Plants added to the landscape in the spring will easily be 2-3 feet tall by 3-4 feet wide by fall. Midspring is a great time to plant.

By admin on Monday, March 03, 2014

Ornamental Plant of the Week
March 3, 2014
Heat-tolerant Osteospermums

Heat-tolerant osteospermums are becoming more popular as cool-season-to-warm-season transition bedding plants in the landscape. These plants are commonly referred to as African daisy.

The LSU AgCenter recommends planting in February through March. Plants can tolerate a light frost. Daisy-like flowers cover the canopy. Plants reach a height of 12 to 16 inches in the landscape.

Consider the more heat-tolerant varieties – including the popular Voltage Yellow (yellow blooms) and the new White Lightning (white flowers with yellow undersides to the petals). Both of these varieties have lasted in bloom until mid- to late summer in south Louisiana landscapes.

Plant in partial sun to light shade for best results.

 

Ornamental Plant of the Week
March 10, 2014
Mayhaws

Mayhaws are one of the most widely known of the native fruit tree species found in Louisiana. Interest in mayhaws has been building over the past 20 years, and these plants are now managed in fruit orchards around the state. You can also find mayhaw trees at local garden centers during winter and early spring. Mayhaws make a wonderful addition to any landscape.

A member of the hawthorn family, mayhaws are native to the southeastern United States. Trees usually reach 20-30 feet tall at maturity and are native to habitats that have low, wet, slightly acid soils. Trees perform best in full sun to partial shade.

The mature canopy is ball-shaped and is highly desirable as a small ornamental landscape tree. The mounded form and exfoliating bark also are desirable landscape characteristics. Mayhaws are highly desirable for attracting wildlife.

By admin on Tuesday, February 18, 2014

Ornamental Plant of the Week
February 18, 2014
Amazon Dianthus

Some of the best dianthus for Louisiana is the Amazon series. These are very prolific flower producers and can be planted September through early November or February through March. Flower heads are large and will last until mid-May in south Louisiana and until late May or early June in north Louisiana.

This series also has cut-flower potential. Remove old flower stalks to encourage the continuation of the bloom season. Flower colors available in the Amazon series are Rose Magic, Purple, Cherry and Neon Duo. Amazon dianthus are Dianthus barbatus interspecific hybrids. Amazon dianthus are Louisiana Super Plants.

Ornamental Plant of the Week
February 25, 2014
Supertunias

With an ever-increasing number of color combinations now spread over 33 available cultivars, the Supertunia petunias from Proven Winners continue to impress in container and landscape trials across the Southeast. Some of the favorites at the LSU AgCenter have been Silverberry, Bubblegum and Fuchsia. Pretty Much Picasso also belongs to the Supertunia group. There is also a mini group of Supertunias. These plants are very vigorous growers and great for late-winter to early-spring planting. Plants can reach a height and spread of 24-36 inches. Petunias prefer full sun and well-drained soil.

By admin on Tuesday, February 04, 2014

Ornamental Plant of the Week
February 4, 2014
Chinese and American Fringe Trees

The American fringe tree (Chionanthus virginicus) produces clusters of flowers with long, narrow, greenish-white petals that are produced in masses all along the branches. The narrow petals and hanging habit give the flowers a fringe or beardlike appearance. In the wild, you usually see them growing on the edge of the woods; they thrive in full sun to partial shade in well-drained locations.

The Chinese fringe tree (Chionanthus retusus) also grows well here and is even showier than our native species (photo). Bloom masses on the Chinese species are impressive. Chinese fringe trees need pruning when young to encourage good trunk development.

Ornamental Plant of the Week
February 11, 2014
Pericallis

Most of us probably do not know what pericallis is, but the Senetti series contains the first repeat-blooming cultivars. They are a good plant for late winter through late spring flower color. Cold hardy to the 30s, these plants will need some protecting if planted in a landscape setting before the last killing
frost/freeze. Good for container gardens.

By admin on Monday, January 20, 2014

Ornamental Plant of the Week
January 6, 2014
Lobularia

Snow Princess lobularia is a unique breakthrough in the genus for heat tolerance and extended-season performance. This sterile lobularia is extremely vigorous, and because it puts no energy into setting seed, it has an incredibly long bloom time. Typically the plants do well in south Louisiana from midwinter through late spring.

Snow Princess displays mounds of fragrant, white blooms from January through July. It creates a great hanging basket or window box and is a perfect filler in combinations. New introductions in this group from Proven Winners are Blushing Princess and Frost Knight. Blushing Princess lobularia colors better with cooler nights. It has 70 percent the growth vigor of Snow Princess. The Frosty Knight lobularia has 50 percent the growth vigor of Snow Princess and has variegated foliage. Frosty Knight is a sport of Snow Princess.

Great hanging basket and container plant. Limited irrigation needed.

Ornamental Plant of the Week
January 13, 2014
Taiwan Cherry

The Taiwan flowering cherry (Prunus campanulata) blooms in late January through February in Louisiana. The attractive flowers are vibrant, deep pink and are produced in great abundance before the leaves emerge. This is one of the few flowering cherries that grows and blooms reliably this far south. The Okame flowering cherry is another type that will grow successfully in Louisiana and is especially recommended for North Louisiana because it blooms later and the flowers are less likely to be damaged by a freeze. Pale pink flowers are produced in mid February through early to mid March.

By admin on Monday, December 23, 2013

Ornamental Plant of the Week
for December 23, 2013
Trailing Pansies

Trailing type pansies were new to the market in 2012. The development of these pansies involved more than 10 years of breeding.
Varieties included in trailing type pansies include the Cool Wave, Wonderfall and Freefall series.
Pansies that have a trailing habit do well in baskets, containers and landscape beds. They have “twice the spread” and “double the color” of older pansy varieties.
A broad spectrum of flower colors is becoming available in these type pansies. Trailing pansies have heat tolerance more similar to violas and an ideal medium flower size. These flowers hold up well in the landscape.
To enjoy pansies all season long, you have to consider landscape bed preparation, fertilization, soil pH, irrigation practices and more. Trailing pansies need to be spaced 10-15 inches apart.
Properly prepare the landscape bed to allow for good internal drainage and aeration. If you purchase soil, make sure it comes from a reputable supplier. Cheap soil often is not worth the price you pay.
Make sure landscape beds for pansies have a soil pH between 5.5-6.0. Pansies require more acid-soil growing conditions than some other bedding plants.

Ornamental Plant of the Week
for December 30, 2013
Nicotiana/Dwarf Flowering Tobacco

Dwarf flowering tobacco is a Nicotiana. These are a good alternative, cool-season bedding plants for south Louisiana. Most of these for landscape use are “dwarf” in size but still reach heights of 24 inches. Nicotianas have less cold hardiness than some other cool-season flowers, however, so that needs to be considered. In south Louisiana, they should be able to withstand winter temperature conditions as long as plants are hardened off some before the first frosts and freezes. You also can plant them in mid- to late February in south Louisiana and in north Louisiana. Plants last until late spring. Flower colors available include white, lime, rose, red and more. They do best during the cool season of the year in a full sun planting but will perform better into late spring if partial shade is provided. The Nicki, Perfume and Saratoga are popular series available.

By admin on Monday, December 09, 2013

Ornamental Plant of the Week
for December 9, 2013
Chinese Pistache

The Chinese pistache (Pistachio chinensis) is a medium-sized ornamental shade tree known for spectacular orange, red and crimson fall foliage colors. The tree will reach 30-35 feet tall and 25 feet wide at maturity. Young plants take a while to develop a nice branch structure. Few if any disease and insect problems are an issue with Chinese pistachio. It’s a great under-used tree with landscape potential.

Ornamental Plant of the Week
for December 16, 2013
Pine Trees

Pines are one of the many great native tree species that we have in Louisiana. Pines, along with bald cypress, southern magnolias and oaks, are the native trees most of us readily think of. In Louisiana we have several species of pine trees that are native. These include loblolly pine (Pinus taeda), Virginia pine (Pinus virginiana), longleaf pine (Pinus palustris), shortleaf pine (Pinus echinata), spruce pine (Pinus glabra) and slash pine (Pinus elliottii).

The best pine tree for landscape use in Louisiana is the spruce pine. It has a slow-to-moderate growth rate and matures at a size that works in medium- to large-size landscape settings. Spruce pines are much more adapted to adverse or varying soil moisture and pH conditions when compared with other pine species. Spruce pines can tolerate neutral to slightly alkaline soils and can also grow better in more poorly drained soils that have some clay – although their growth certainly will be slower than if they were planted in more ideal silty, acid soil. Virginia pines are also slightly more tolerant of adverse growing conditions.

By admin on Monday, November 25, 2013

Ornamental Plant of the Week
for November 25, 2013
Camelot Foxgloves

The Camelot series foxglove (Digitalis) is seed-propagated and includes four colors – Camelot Cream, Camelot White, Camelot Rose and Camelot Lavender.
This is the best foxglove for Louisiana so far, and it is notable for its large spikes of outward-facing, bell-shaped flowers. It is best planted in September through November or in February through early March.
An early fall planting will bloom in fall and continue through spring. A late-winter planting will bloom in spring. First bloom will last four to six weeks, with secondary bloom lasting another month. Flowering will last through mid-May.
Rain and wind can cause stems to fall over on 30- to 36-inch-tall plants. Plants perform well in sun, partial sun and partially shaded locations. A past Louisiana Super Plant recipient.

 

 

Ornamental Plant of the Week
for December 2, 2013
October Magic Series Camellias

New to the plant market a few years ago is the great October Magic series of Camellia hiemalis developed by Bobby Green of Green Nurseries in Fairhope, Ala. Plants include October Magic Bride, October Magic Dawn, October Magic Inspiration, October Magic Orchid, October Magic Rose and October Magic Snow.
Bride is a small, very double, pure pink flowering shrub with a dense conical growth habit. Mature size is 4 to 6 feet tall by 3 to 4 feet wide. This variety is a profuse bloomer.
Dawn has large rose-form flowers. Blooms are blends of pink and resemble flowers of a Camellia japonica. Plants reach 4 to 6 feet tall and 3 to 4 feet wide. The variety is great for a single specimen planting or for use as an intermediate hedge. Plants have dark green foliage.

By admin on Monday, November 04, 2013

Ornamental Plant of the Week
for November 4, 2013
Sorbet Violas

Want to add color to your fall, winter and early spring garden? Plant some colorful Sorbet series violas. Sorbet violas are the best-flowering violas in LSU AgCenter trials. The small, delicate, bright flowers cover the plant from late fall through spring. Sorbet violas have the most uniform plant habit and produce masses of bright blooms on compact plants. Excellent overwintering and cold hardiness allow planting Sorbet violas in early fall for color through winter and into early spring. This charming plant is an early bloomer and comes in a multitude of colors. Use this fall 2012 Louisiana Super Plant to add a punch of color to your winter landscape.
These popular cool-season flowers do best in full sun and grow 6 inches tall by 12 inches wide. Space individual plants 10-12 inches apart. Fertilize at planting with a slow-release fertilizer or liquid feed every two to three weeks through late fall and winter. With a nice spring, Sorbet violas last until early or mid-May.

By admin on Tuesday, October 15, 2013

Ornamental Plant of the Week
for October 28, 2013
Diamonds Blue Delphinium

An exceptional, blue-flowered cool-season bedding plant called Diamonds Blue delphinium (Delphinium chinensis Diamonds Blue) is a Louisiana Super Plants selection for fall 2013. If you love blue flowers, Diamonds Blue delphinium is really, truly blue – an intense, vivid, almost-electric blue that sings out loud and clear in the flower garden. Blue flowers are so useful in the garden. Diamonds Blue is a cultivar of Delphinium chinensis, a species that is bushier and lower-growing. These plants are only about 14 to 16 inches tall and about 12 to 14 inches wide. This compact growth habit makes them ideal for containers and cool-season flower beds planted to the front or middle of the bed.
The uniquely beautiful flowers and compact growth habit are not the only reasons Diamonds Blue was named a Louisiana Super Plants selection. In variety trials at the LSU AgCenter Hammond Research Station, Diamonds Blue showed more vigor and stamina over a longer period than other delphiniums. And this cultivar produces more flowers over a longer blooming season as well. There are no major insect or disease problems.
The foliage of Diamonds Blue delphinium is a beautiful background to the flowers. Rich green and finely divided, the texture is delicate. But don’t let that fool you. These plants are tough and resilient and hardy through the freezes of winter.
 

By admin on Monday, October 07, 2013

Ornamental Plant of the Week
for October 7, 2013
Drift Roses

The first Louisiana Super Plant from the LSU AgCenter for fall 2013 is the Drift series of roses. Drift roses fit a special niche in the shrub-rose market. These roses are from Conard-Pyle/Star Roses, the same folks that gave us the Knock Out series of low -maintenance landscape roses. All colors in the Drift series of roses are Super Plants.
Colors in the Drift roses include pink, coral, red, peach, apricot (double blooms), sweet (clearer pink double blooms) and the new popcorn (whitish yellow). Choose from these seven varieties that bloom from spring to early frost. Ranging from scarlet red to bright soft peach, they provide the gardener with a complete range of color solutions for landscape use or in containers. We find that Drift roses have about five flower cycles yearly. The spring bloom in April and the fall bloom in October, like with most other roses, are the peak times for best performance. The late-spring to early summer second bloom is also impressive.

By admin on Monday, September 16, 2013

Ornamental Plant of the Week
for September 16, 2013
Purple Coneflowers

One of the most popular herbaceous perennials in Louisiana is the purple coneflower. The scientific name of this plant is Echinacea purpurea. It is native to a geographic area from the Midwest into the southeastern United States.
Purple coneflowers are drought tolerant, tough and long-lived. Flowering usually starts in late April or early May. You can get good re-bloom on most coneflowers through summer and fall.
Flower petals in coneflowers have typically been in the soft lavender to purple color ranges. Now white forms are available. Magnus is a popular variety that was the Perennial Plant of the Year in 1998. This selection has vibrant, rose-purple flowers. Bravado is a variety with 4- to 5-inch fragrant flowers. White Swan is a white-flowering form. A new seed-propagated series of coneflowers, the Pow Wow variety, became available in 2011.
With hybridization of coneflower species, a whole new group of coneflowers, called the Big Sky series, has added to the color range. The Big Sky coneflowers come in shades of oranges, reds and yellows. The varieties Twilight (rose-red flowers), Harvest Moon (earthy gold flowers), Sundown (russet orange flowers), Sunrise (citron yellow flowers) and Sunset (orange flowers) comprise the series collection. These varieties have been available at garden centers in Louisiana the past three years. These are not as reliably perennial as we would like to see.

By admin on Monday, September 02, 2013

Ornamental Plant of the Week
for September 2, 2013
Nuttall Oak

Oak trees are very popular in Louisiana landscapes. We are all very familiar with the evergreen Southern live oak. Popular deciduous oak trees in Louisiana are water, shumard, southern red and willow, but the one with possibly the best potential for landscape use is the nuttall oak. These oaks are underused by homeowners and professional landscapers and offer many advantages. Nuttall oaks are increasingly available at garden centers across the state.
Nuttall oaks are native to Louisiana and are one of the best of the oak species in regard to adaptability to a wide range of soil conditions. Nuttall oaks prefer loamy, well-drained soil but do well in more poorly drained clay type soils. Soil pH is not a major factor. In native stands you will see nuttall oaks in association with swamp red maples, water oaks and black willow.
A moderate-to-fast growth rate is characteristic of nuttall oak. An average mature height of 50 feet or so is common in the landscape, although individual trees can easily reach 80-100 feet tall. Average spread is anywhere from 25-40 feet. Nuttall oaks have better branch development at a younger age than other oak trees. The canopy is oval to rounded as the tree begins to mature, with the upper branches ascending and the lower branches being more horizontal in habit. The foliage is coarse-textured with 5-9 lobes.
Fall foliage color is typically good to excellent on nuttall oaks. Color is better in north and central Louisiana than in south Louisiana. Acorn production is good on nuttall oaks, and they are a great source of wildlife food. Nuttall oak have no pests or disease issues of major concern. Improper pruning cuts can lead to stem cankers.
We have very few oak trees that are better for landscape use and adaptability than nuttall oak. The LSU AgCenter has nuttall oak listed as a top-rated tree for the New Orleans area. Their tolerance to varying soil conditions, moderate growth rate, great fall foliage color and good branching characteristics make for outstanding performance.

Ornamental Plant of the Week
for September 9, 2013
Cassias

One of the popular fall-flowering plants offered at many retail garden centers in Louisiana during late summer and early fall is cassia. Sometimes these plants are now called sennas. Cassias are prolific fall bloomers and are one of the plants in landscape settings that are a “showstopper” in October and November. They produce a massive bloom display that attracts plenty of attention.
One of the most common of the cassias is the candlestick tree. It makes a candle-shaped bloom of golden yellow flowers. The other species also have golden yellow flowers.
Are cassias annuals or perennials? They typically survive winters in south Louisiana very well. The candlestick cassia is the one that is most likely to not survive winter growing conditions.
All species have a tendency to need trimming and pruning occasionally to keep the plants manageable. Right after new growth begins in spring is a great time to remove dead wood. You can also prune slightly during the growing season to manage growth. But don’t get carried away with pruning after early summer or you will sacrifice fall flowers.
Cassias are trouble-free and easy to grow. Plant them in full to partial sun and fertilize regularly. Cassias need minimum irrigation once established.
Seeds of all species germinate readily, but people have the most success with seed from candlestick trees. Plants also can be propagated by stem cuttings. Cassias make a great background to herbaceous perennial borders and are highly desired by butterflies.

By admin on Tuesday, August 20, 2013

Ornamental Plant of the Week
for August 20, 2013
Durantas

Golden dewdrop, pigeon berry and sky flower are common names for durantas.
The most common varieties of these plants have green foliage with light to medium-blue flowers. Bloom occurs early summer through early fall. Then small golden berries develop.
Durantas prefer full sun and are very drought tolerant and low maintenance in the landscape. Plants can be lightly pruned through the warm season to control size and growth as desired. Plants can reach 5 feet tall in an annual landscape and even larger in warm climates south of Interstate 10.
Durantas are recommended as a perennial in south Louisiana. They make great annuals elsewhere, although in some years they may behave as perennials in central and north Louisiana.
Sapphire Showers is a new blue-flowering variety. You may see green-and-white variegated foliaged Variegata and Silver Lining varieties. Lemon Drop has greenish-yellow foliage. You can also plant the dwarf, chartreuse-foliaged Cuban Gold or Gold Mound and the large, greenish-with-golden-yellow-foliaged Gold Edge.

Ornamental Plant of the Week
for August 27, 2013
Tihouchinas

Princess flowers (Tibouchina) include several species. One of the lesser known species is glory flower (T. grandifolia), also known as big leaf tibouchina. It has much larger foliage and larger flowers than the other commonly grown princess flowers. Considered a tropical or tender perennial, the plant is winter-hardy most
years in USDA hardiness zone 9A, which is generally south of I-10/I-12. Purple flowers start in late summer and continue through fall. Plants can be easily rooted using softwood cuttings. A few garden centers in Louisiana sell this plant, which needs to be used more.
A smaller-growing version is called Athens Blue or dwarf tibouchina. We have been growing it at the LSU AgCenter the past five years, and it is a great landscape performer with profuse blooms from late spring through fall on 18- to 24-inch-tall plants. A variegated-foliage form of this plant is now available.
Plants prefer full sun. These do not need a lot of fertilizer and are low water users in the landscape.

By admin on Tuesday, August 06, 2013

Ornamental Plant of the Week
for August 6, 2013
Pride of Barbados

Pride of Barbados is a great, small-growing tropical tree. You see more of these planted in Houston, San Antonio and Austin, Texas, than you do in Louisiana, but we should use these plants much more. The scientific name of this plant is Caesalpinia. Plants usually are 5-8 feet tall by fall and start producing orange-red flowers on the terminal growth in early to midsummer and continue through early fall. Stems are spiny. Foliage is fern-like, and since this plant is in the legume family, it sets seed pods similar to what you see on beans. These are perennial in south Louisiana. They have typically been annuals in north Louisiana, but several gardeners are now reporting over-wintering success.

 

 

Ornamental Plant of the Week
for August 13, 2013
Tapioca Plant

Continuing the tropical theme for ornamental plants of the week in August is cassava, also called tapioca plant.
This is tropical, shrubby perennial that we normally treat as an annual. But south of interstate 10 in Louisiana in warmer locations we can see this plant over-wintering. This plant goes by the scientific name of Manihot. The variegated form is the one you see used in landscapes. These are not abundantly available at garden centers except during summer. Plants do best in full sun to partial sun and can typically reach heights of 4 feet in the landscape. Low maintenance requirement and a great foliage plant addition to the tropical summer landscape.

 

By admin on Monday, July 15, 2013

Ornamental Plant of the Week
for July 22, 2013
Pond Cypress

Louisiana’s state tree is the baldcypress. This tree goes by the scientific name of Taxodium distichum. It is one of our most distinguished native trees and is widely used in Louisiana landscapes. There are some trees similar to baldcypress used in Louisiana. A botanical variety of baldcypress is called pond cypress (Taxodium distichum var. nutans). Pond cypress has finer-textured foliage than baldcypress and is more upright growing. Foliage color can be nice in spring with new growth, and most trees have attractive, rusty-brown fall foliage color that lingers into early to mid-December in south Louisiana. The pond cypress can usually be “picked out” of a lineup of cypress trees due to the distinguishing foliage characteristics. It’s worthy of increased use in Louisiana.

 

Ornamental Plant of the Week
for July 29, 2013
Ornamental Sweet Potatoes

Ornamental sweet potatoes are a popular, warm-season annual for adding foliage colors to the summer landscape. The original varieties include plants with leaves that are chartreuse-lime green (Marguerite), blackish purple (Blackie, Black Beauty, Ace of Spades) and tricolored (Pink Frost).
New ornamental sweet potato varieties recently introduced have various leaf shapes and growth habits in addition to new foliage colors. These sweet potatoes have been selected for shorter stem lengths between the leaves and reduced root size. They are more compact than most other ornamental sweet potato varieties.

By admin on Monday, July 01, 2013

Ornamental Plant of the Week
for July 1, 2013
Zahara Zinnias

The Zahara series of zinnias from PanAmerican Seed are landscape zinnias for tough summertime performance. Colors available include yellow, cherry, scarlet, starlight rose, white improved, fire, coral rose and the new sunburst. Double forms also are available in cherry, fire and strawberry. Mixes include raspberry lemonade, bonfire and the double duo. 14-18 inch plants in the landscape. This series of zinnia is a Zinnia marylandica species.

Ornamental Plant of the Week
for July 8, 2013
Angelonias

Angelonia is a great bedding plant for the warm season. Angelonias come in white, pink, blue, lavender, lavender pink and raspberry flower colors. Some folks call angelonias “summer snapdragons.” They come in both seed -propagated and vegetatively propagated varieties. The Serena series is a Louisiana Super Plant from spring 2011. The new Archangel series are very nice. New for 2013 is the Serenita series – a slightly smaller version of the Serenas. Other series and varieties are also available and are good performers. They make nice border plants and can be used in container combos. Most angelonias reach heights of 14-20 inches in the landscape. These can be added to the landscape midspring through midsummer. We find angelonias do best in drier years. Minimize irrigation and minimize nitrogen fertilization to aid bloom performance through fall. Plants need full sun and a pH of 6.0-6.5. Fertilize lightly. Dead-heading is not needed and has been considered to slow the re-bloom potential.

Ornamental Plant of the Week
for July 15, 2013
Turk’s Cap


Turk’s Cap (Malvaviscus arboreus var. drummondii) is a pass-along kind of old garden plant that still has great potential in gardens and landscapes of today. These plants have recently been named Texas Superstars. We have ten cultivars being grown at the station in Hammond – pink, red, Big Momma, Spreading Red, Variegated, Pam Puryear, White Lightning, Giant White, Giant Red and Giant Pink. Flowers come in red (the most common), pink and white. Plants do best in light shade during the afternoon hours and bloom the best from mid- to late summer through fall. The attractive flowers attract hummingbirds and butterflies. Plants will sucker and spread to some degree. This native plant is deserving of more use.

By admin on Monday, June 24, 2013

Ornamental Plant of the Week
for June 24, 2013
African Rose Mallow or Hibiscus acetosella
(from Allen Owings)

Hibiscus acetosella, commonly referred to as false roselle and African rose mallow, are great foliage plants for the summer and fall landscape. When planted in the spring, plants can easily reach heights of 5 feet or more by fall. Prune every month or so for the first couple months after planting to produce a bushy, slightly more compact plant. There are several cultivars on the market – these include Maple Sugar, Panama Red, Haight Ashbury and Red Shield. New a couple years ago was Mahogany Splendor from PanAmerican Seed – it is part of their Fantastic Foliage program. Mahogany Splendor has bronze foliage in some seasons and under some light conditions. Most of the Hibiscus acetosella have reddish foliage. The Haight Ashbury cultivar has multiple foliage shades of cream, pink and burgundy. Panama Red has deeply cut foliage that is rich carmine red. There is a new cultivar that has been released by the USDA-ARS called Sahara Sunset. These plants produce red flowers under short days in late fall and winter in Louisiana. Plants need full sun. They have great drought tolerance. Minimum irrigation is needed. Plants have upright growth forms. Space plants a minimum of 3 feet apart when planting. Plants are deer resistant.

By admin on Monday, June 17, 2013

 

Ornamental Plant of the Week
for June 17, 2013
Durantas
(from Allen Owings)

We have many durantas (golden dewdrop, blue sky flower) around, but the Cuban Gold variety continues to receive extensive use and attention around the Southeast. Plants are low-growing, reaching 18-24 inches in the landscape by fall. Plants prefer full sun. Chartreuse foliage color is constant. These plants are recommended as perennials in USDA hardiness zones 9-11. We have Cuban Gold durantas that are 3 feet tall and being used in foundation plantings as boxwood or similar replacements on the LSU campus in Baton Rouge. It is a great annual in areas north of hardiness zone 9. Regrowth will occur in hardiness zone 8, but the new growth is slow in the spring. This plant is great in LSU AgCenter trials! We use it to frame landscape color beds in the sun garden at the Hammond Research Station. Other duranta varieties recommended for Louisiana include the larger-growing Variegated, Alba, Gold Edge, Purple and Silver Lining, along with the smaller-growing Lemon Drop. (photo – Cuban Gold duranta as a bed edging in the sun garden at the LSU AgCenter Hammond Research Station)

ALLEN OWINGS
Professor (Horticulture)
aowings@agcenter.lsu.edu

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