‘Luisa’ Turnera Holds Great Potential

'Luisa' Turnera Holds Great Potential

Turnera diffusa is a widespread and variable species found throughout the tropical Americas. Commonly known as “damiana,” Turnera diffusa has figured extensively in folk medicine and is particularly noted for its aphrodisiacal properties for which there is scientific support.

In 2005, we conducted a plant exploration in Puerto Rico for species with ornamental potential. In the coastal mogotes (limestone hills) of southern Peñuelas Municipality, we encountered a population of T. diffusa. The population was striking for its small, densely hairy gray-green leaves that we perceived as more attractive than typical of the species elsewhere across its broad range. One individual in the population appeared particularly compact.

Cuttings of this individual were collected and placed at a mist propagation facility at the USDA-ARS Tropical Agricultural Research Station (TARS) in Mayaguez. Once rooted, these were shipped to the National Germplasm Repository at the Subtropical Horticulture Research Station (SHRS) in Miami, where we have propagated and evaluated the plant for the past five years. It has proven to be a dependable, problem-free ornamental with great potential as a perennial in warm climates or for annual use in the temperate zone. We have given this cultivar the name ‘Luisa’ in honor of the author Tomás Ayala-Silva’s late mother, who was an enthusiastic admirer of Puerto Rico’s native flora.

Rooting ‘Luisa’

‘Luisa’ is a multi-stemmed, densely branched evergreen sub-shrub growing to about 2.5 feet tall. The small evergreen leaves are grayish green and aromatic when crushed. The small (1/2-inch) yellow flowers are borne singly in the axils of the more terminal leaves, and though lasting only a single day, are quickly replaced by new flowers the next day.

‘Luisa’ is readily propagated from softwood cuttings throughout the year. We have found that cuttings from actively growing plants treated with a five-second basal end dip in 1,000 ppm indolebutyric acid in 50 percent EtOH root within four to six weeks when placed under intermittent mist.

We have successfully grown the cultivar in five-parts-aged pine bark: four coconut coir dust, one coarse sand (by volume). Rooted cuttings in cell packs are placed directly into 6-inch containers. The plants grow rapidly and will be saleable in 6-inch containers in six to eight months after rooted cuttings are potted. In smaller containers (4 inch), they are ready in four to six months. Trial blocks were situated in the ground at the USDA-ARS National Germplasm Repository in Miami from plants established in 6-inch containers in October 2005, April 2007 and again in March 2009 in crushed limestone and sand-fill soil similar to urban residential lots in much of South Florida. Soil was amended with three inches of 10-year-old aged compost from vegetative solid waste, incorporated into the top six inches of the site substrate.

In The Landscape

In the landscape, ‘Luisa’ should be situated in full sun and on well-drained soils. It is tolerant of alkalinity to a pH of at least 8.5 and grows equally well in slightly acidic substrates (pH 6.5). After establishment, the plant is drought tolerant, requiring supplementary irrigation only during prolonged periods of no precipitation.

Nutritional requirements appear low. We have fertilized field plantings only once annually with no apparent nutritional deficiencies observed. Once each year the plants can be cut back to half their height. No pest or disease problems have been observed in five years of cultivation history in Miami. Fruit set has never occurred at our location, so the threat of weediness appears minimal in contrast to T. subulata and T. ulmifolia, which have naturalized in many subtropical and tropical areas. The rapid rate of growth, ease of propagation and long flowering season suggest ‘Luisa’ could be marketed as an annual beyond its expected hardiness range, which we estimate to be USDA 9B-11 (USDA, 1990). Flowering occurs for most of the year in South Florida, ceasing production only in the coldest months of winter.

‘Luisa’ can be used as an edging, groundcover, bedding plant or as a container plant. Although the flowers are small, they are produced in great profusion and contrast well with the gray-green foliage, creating a conspicuous presentation in the landscape. The dwarf growth habit and small leaves and flowers are markedly different from the coarse, rangy habit of the large-flowered T. ulmifolia and T. subulata.

Small quantities of ‘Luisa’ are available for research and further evaluation purposes by request through the USDA-ARS National Plant Germplasm System as accession PI 659752.

Leave a Reply

2 comments on “‘Luisa’ Turnera Holds Great Potential

More From Varieties...
Suntory Blue Rose Applause

October 21, 2017

Suntory’s Blue Rose ‘Applause’ Now Available to U.S. Florists

‘Applause’ was originally introduced to the U.S. in 2011, and since then it was been successfully tested and selected to meet new market conditions.

Read More

October 17, 2017

14 New Shrubs With Fringe Benefits

What’s popular with shrubs? Consumers want varieties that will give them more return on their investment, in terms of long-lasting blooms and multi-season appeal that lasts from spring until fall and at times stretches into the winter months. Here are 14 new varieties of shrubs and sub-shrubs to consider for your product mix in 2018.

Read More

October 14, 2017

PlantPeddler Hosting Poinsettia Variety Day in December

The event will feature side-by-side comparisons of more than 100 commercial and pre-released varieties from seven breeders.

Read More
Latest Stories
Suntory Blue Rose Applause

October 21, 2017

Suntory’s Blue Rose ‘Applause’ Now Available to U.S. Fl…

‘Applause’ was originally introduced to the U.S. in 2011, and since then it was been successfully tested and selected to meet new market conditions.

Read More

October 17, 2017

14 New Shrubs With Fringe Benefits

What’s popular with shrubs? Consumers want varieties that will give them more return on their investment, in terms of long-lasting blooms and multi-season appeal that lasts from spring until fall and at times stretches into the winter months. Here are 14 new varieties of shrubs and sub-shrubs to consider for your product mix in 2018.

Read More

October 14, 2017

PlantPeddler Hosting Poinsettia Variety Day in December

The event will feature side-by-side comparisons of more than 100 commercial and pre-released varieties from seven breeders.

Read More

October 10, 2017

Coastal Callas Is a Dream Fulfilled for Founder Adrian …

Adrian Espinoza and his family founded Rancho Espinoza Inc. and Coastal Callas in California seven years ago with a mission and purpose to provide consistent quality and reliable supply of calla lilies to the marketplace.

Read More
Azalea Encore Autumn Bonfire

October 4, 2017

Big Changes on the Horizon for Woody Ornamentals

The future looks bright for the woody ornamentals market, with exciting new varieties in the pipeline that will offer greater disease resistance, cold hardiness, bloom capacity, and more.

Read More

October 3, 2017

25 New Blooming Potted Plants for Luxury Sales

Consider these new blooming potted plant varieties that offer full blooms, unique foliage, and a touch of extravagance and easy maintenance for time-strapped customers who want to pamper themselves.

Read More
Hydrangea 'Berry White' (Bailey Nurseries)

October 2, 2017

Woody Ornamentals Market Set for Growth

The woody ornamentals market is looking up. Now, out-of-the box thinking about product offerings and consumer education will keep things moving in the right direction.

Read More

September 27, 2017

New Mum Intros From California Spring Trials 2017

For fall gardening product selection, you can't go wrong with offering mums. Here are a few of the new introductions that we saw at California Spring Trials 2017 that will be making their retail debut in 2018.

Read More
Hydrangea ‘Endless Summer BloomStruck’ (Bailey Nurseries)

September 26, 2017

Bailey Nurseries Enhances Product Development Program, …

Plant Introductions, which Bailey purchased almost three years ago, is being rebranded as Bailey Innovations, an entity that will breed and trial new varieties in Georgia.

Read More
Green Fuse Lupine Staircase Pink

September 24, 2017

How to Effectively Grow Staircase Lupine

The Staircase Lupine series, part of Green Fuse Botanicals’ First Light Perennials collection, has the potential to put on a great display with solid and bicolor hues.

Read More
Terra Nova 2018 Catalog

September 23, 2017

Terra Nova Nurseries’ Latest Plant Catalog is Now Avail…

The new 2017-2018 plant catalog, which features hundreds of varieties, series, and collections from Terra Nova Nurseries, pays homage to the company’s 25th anniversary.

Read More
Armitage GWA Buffalo Tour 5

September 21, 2017

Tour of Buffalo Gardens Reveals Hidden Gems And Communi…

This past August, Allan Armitage joined the Association for Garden Communicators on a tour of Buffalo. It was a reminder that that we can make a difference in neighborhoods, in cities, and in people’s lives.

Read More
Suntory Grandessa argyranthemum - feature

September 18, 2017

Breeders Open Availability for Unrooted Cuttings; Here&…

With new avenues for buying young plants for vegetative production, growers should have an easier time finding availability and receiving shipments of unrooted cuttings for the coming seasons.

Read More
Ball, Tagawa Succulents Partnership

September 14, 2017

Ball Seed to Partner With Tagawa Greenhouses on New Suc…

The new program includes in-demand retail products that are popular with younger shoppers, allowing growers to easily build a comprehensive succulent program and stay on-trend in the marketplace.

Read More
Strait-Laced Elderberry

September 10, 2017

Check Out the Top Varieties On Display at Farwest 2017

A panel of plant experts, along with show attendees, selected their favorite offerings during the Farwest 2017 New Varieties Showcase.

Read More

September 5, 2017

Hort Couture Announces New Propagation and Broker Partn…

The new grower-propagator partners are deeply vested in the independent garden center channel with propagation expertise, as well as finished production focused on the independent grower.

Read More
Helianthus Sunfinity (Syngenta Flowers)

September 3, 2017

Growing Tips for Helianthus Sunflower ‘Sunfinity…

This annual sunflower is a profuse bloomer with strong branching that produces multiple flowers per plant from spring to fall.

Read More
Ball Seed Field Day 2017

September 2, 2017

Highlights from Ball Seed’s Annual Field Day and Landsc…

Attendees of the one-day event had the opportunity to see new plants in up-close-and-personal trials, and engage with speakers and product experts.

Read More