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Annuals

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Oklahoma Proven is a plant promotion program coordinated by faculty in the Department of Horticulture and Landscape Architecture at Oklahoma State University. The goal of the program is to recommend plants well-adapted for use across Oklahoma.

 

 

Annual for 2017

Firecracker Flower

Crossandra infundibuliformis

Firecracker flower, is native to India and Sri Lanka where it is a tropical evergreen subshrub that grows 1-3 feet tall. Flowers are apricot to salmon pink in color and form in terminal racemes. Yellow and red flowered forms are also available. Plants bloom throughout the summer and attract pollinators. Leaves of firecracker flower are shiny dark green. ‘Orange Marmalade’ has long lasting blooms on a plant that thrives with heat and humidity. Large clusters of frilly, bright orange flowers shine against the glossy green foliage.

Firecracker flower prefers light, organically rich, medium moisture, well-drained soils in full sun or part shade, but will tolerate bright full shade. Plants thrive in warm, humid weather and have no serious insect or disease problems. Firecracker flower is beautiful in beds, borders, containers or as a houseplant.

  • Exposure: Full sun to part shade
  • Soil: Moist, well-drained soil
  • Hardiness: Use as an annual

 

 

 

Annual for 2016

Annual Vinca (improved, resistant varieties)

Catharanthus

Annual vinca, also goes by Madagascar periwinkle and other common names, tolerates the heat and humidity of the southeast. Full sun and warm soil temperature is required for this species to thrive and it is tolerant of low fertility soils and is drought tolerant. Flower colors come in shades of white, pink, red, and purple. Plants grow 6 to 12 inches tall and 8 to 24 inches wide depending on cultivar. Improved cultivars provide an abundance of flowers on stocky plants and disease resistance, which is very important with this species. Improved cultivars include plants in the Cora series, Mediterranean series, Titan series, and many others.

  • Exposure: Full sun to part shade
  • Soil: Well-drained, slightly dry soil
  • Hardiness: Use as an annual

 

 

 

Annual for 2015

Spider Flower (improved varieties)

Cleome hybrids

Spider flower is a unique plant with palmately compound leaves, interesting, fragrant flowers, and an old fashion look. Flowers have abnormally long stamens that gives the flower a frilly look and is likely where the common name of Spider flower comes from, resembling spider legs. Flower colors come in shades white, pink, blue, and purple. Plants can grow 3 to 6 feet tall depending on cultivar. Improved cultivar provide an abundance of flowers on stocky plants. Improved cultivars include plants in the Sparkler series, the Spirit series, and Senorita Rosalita (vivid pink blooms) and Senorita Blanca (white blooms with pale lavender blush). Spider flower attracts butterflies and hummingbirds and goes well with a cottage style, wildflower design, or mixed border.

  • Exposure: Full sun to part shade
  • Soil: Moist, well-drained soil
  • Hardiness: Use as an annual

 

 

 

Annual for 2014

‘Big Twister’ Corkscrew Rush

Juncus effusus 'Big Twister'

Corkscrew rush with its uniquely twisted stems, though relatively small (18-24” high and wide), still commands attention in any garden space. The stems curl and spiral creating a tangled mass. Corkscrew rush grows in full sun or part shade and prefers moist soils. Happy even submerged in water, it is perfect for a water garden. Corkscrew Rush also is an excellent accent plant for containers. Though considered hardy to about zone 6, it tends to be more of a tender perennial in our area. Its annual nature may be due to the dry winters and the drastic temperature fluctuations we often experience .

  • Exposure: Full sun to part shade
  • Soil: Very moist to wet, acidic
  • Hardiness: Use as an annual

 

 

 

Annual for 2013

Dakota Gold, Sneeseweed

Helenium 'Dakota Gold'

Common names for Helenium include sneezeweed and bitterweed, a native wildflower of Texas. Dakota Gold is a cultivar with excellent ornamental qualities and because it is native to Texas it is also very tough and tolerates heat and dry conditions. Dakota Gold grows as low, 6” to 8” mounded cushions, of fine, dark green foliage covered with golden yellow flowers all summer long. Dakota Gold looks great in beds, containers, rock gardens, borders, and as an accent.

  • Exposure: Full sun
  • Soil: Almost any soil (well-drained)
  • Hardiness: Use as an annual

 

 

 

Annual for 2012

Magilla™ Perilla

Perilla frutescens Magilla™

Known for its brightly colored leaves of dark purple to hot pink and green, Magilla Perilla is a vigorous annual. Magilla Perilla is a coleus look-alike, is in the same family as coleus, and has similar characteristics and growing needs. The species, Perilla frutescens, can be weedy, but Magilla is well behaved due to sterile seeds. It grows into a 24” tall mound and is heat tolerant. Magilla Perilla looks great in beds, mixed borders, and is spectacular in a container planting.

  • Exposure: Full sun to part shade
  • Soil: Well-drained, moist
  • Hardiness: Use as an annual

 

 

 

Annual for 2011

Pink Crystals Ruby Grass

Melinus nerviglumis 'Savannah'

Pink Crystals Ruby Grass is a warm season grass that likes it hot and performs best in those conditions. Growing only 18 to 22” tall, it is an attractive ornamental grass with blue green foliage and ruby-pink blooms with glistening silky hairs in late spring. Flowers retain their color even when dried and may be used for cut flower arrangements. Pink Crystals Ruby Grass is excellent in beds, borders, and is spectacular in a container planting.

  • Exposure: Full sun to part shade
  • Soil: Well-drained
  • Hardiness: Use as an annual

 

 

 

Annual for 2010

Silver Falls Dichondra

Dichondra argentea

‘Silver Falls’ Dichondra was selected for its very low growing, creeping trailing habit and beautiful silvery gray leaves that are shaped like miniature lily pads. Silver Falls is actually a selection of a dichondra species native to southwest Texas and Mexico so it is quite heat and drought tolerant. Growing only 2” tall and 3’ to 4’ wide it is an attractive groundcover, but is also spectacular in a container planting or hanging basket, spilling over a retaining wall, or when used in a rock garden.

  • Exposure: Full sun to part shade
  • Soil: Well-drained
  • Hardiness: Use as an annual

 

 

 

Annual for 2009

Diamond Frost® Euphorbia

Euphorbia 'Inneuphdia'

Euphorbia is a fine-textured mounding plant used as an annual in Oklahoma. The simple white flowers bloom from spring until first frost and the plant forms a 2’ to 3’ sphere. Diamond Frost® can be used as a mass planting, alone in a container, or mixed with almost any other plant. Its fine sprays of foliage and flowers will weave through other plants making it a perfect complement for almost anything from poinsettias to petunias. It is an excellent background plant, filler, or specimen, proving to be an extremely beautiful and versatile new introduction.

  • Exposure: Full sun to part shade
  • Soil: Moist, well-drained
  • Hardiness: Use as an annual

 

 

 

Annual for 2008

Spilanthes

Acmella oleracea 'Peek-A-Boo'

‘Peek-A-Boo’ Spilanthes was selected for its yellow flowers, each with a red eye poking up out of the foliage. The green foliage has a purple tinge in full sun turning more purple as fall approaches and the foliage can be used in salads or cooked as a green. Spilanthes is also known as the Toothache Plant because it has been used to numb pain. In the garden it is a great conversation piece when combined with other plants in a mixed container or it can be used as a flowering groundcover growing 12 to 15 inches tall and spreading 24 to 30 inches.

  • Exposure: Full sun to part shade
  • Soil: Moist, well-drained
  • Hardiness: Use as an annual

 

 

 

Annual for 2007

Blanket Flower

Gaillardia

Gaillardia is a genus of native wildflowers that have captivated gardeners with bright red and yellow flowers and an ability to bloom in hot, dry conditions. The native species, Gaillardia pulchella, is Oklahoma’s state wildflower and makes an excellent garden plant. Hybrids (Gaillardia x grandiflora) and new cultivars have been introduced that expand the color range and form of Gaillardia including: ‘Goblin’ (dwarf form), ‘Fanfare’ (interesting trumpet-shaped flowers around the central disc), ‘Arizona Sun’ (compact plants with a long period of bloom), and ‘Summer’s Kiss’ (yellow-apricot flowers), among others. Gaillardia is often a perennial, but it also reseeds readily creating drifts of color in the garden or meadow. Allow the seed heads to dry on the plant for maximum reseeding and floral display the following summer.

  • Exposure: Full sun
  • Soil: Well-drained
  • Hardiness: USDA Zone 4

 

 

 

Annual for 2006

Wishbone Flower, Summer Wave™ Series

Torenia fournieri

The Summer Wave™ Series is a collection of hybrid Torenia, or wishbone flowers, that thrive in the summer heat. The plants form a 6" high by 12" wide mound that is great for the border, in a pot, or mixed with other plants in a larger container. The Summer Wave™ Series is comprised of the following cultivars: ‘Amethyst’, ‘Blue’, ‘Large Violet’, and ‘Lavender Blue’. Each produces flowers from spring until fall, and each flower has a wishbone at its center, thus the name.

  • Exposure: Partial shade
  • Soil: Moist, well-drained
  • Hardiness: Use as an annual

 

 

 

Annual for 2005

Summer Snapdragon

Angelonia angustifolia

Summer snapdragon is a tropical sub-shrub that can be used as an annual in Oklahoma and will bloom from summer until the first frost. Orchid-like flowers are produced on 2' tall spikes and depending on cultivar, flower color ranges from blue to purple, pink, or white with bicolor forms also available. Summer snapdragon may be used as a bedding plant, to add color to a mixed border, or in a container. It is drought tolerant and loves full sun and summer heat.

  • Exposure: Full Sun
  • Soil: Well-drained
  • Hardiness: Use as an annual

 

 

 

Annual for 2004

Firebush

Hamelia patens

This Central and South American native is a small tree when grown in the deep South but is best used as a heat tolerant annual in Oklahoma. The lush green foliage can produce a dense mound over three feet high in full sun and color is added by the interesting orange-red flowers and the reddish tinge on the leaf petioles. Firebush thrives in the summer heat and attracts hummingbirds and butterflies to the garden.

  • Exposure: Full
  • Soil: Well-drained
  • Hardiness: Use as an annual

 

 

 

Annual for 2003

Yellow Bells

Tecoma stans

Yellow Bells is a tropical shrub used as an annual in Oklahoma. It can reach a height of three feet and produces striking yellow flowers above glossy green leaves from summer until frost. Orange flowering cultivars are also available. Give this plant a southern exposure; it loves the heat and sun.

  • Sun Exposure: Full
  • Soil: Moist, well-drained
  • Hardiness: Use as an annual

 

 

 

Annual for 2002

Margarita Sweet Potato

Ipomoea batatas 'Margarita'

Margarita is a spreading vine with chartreuse leaves, excellent as a ground cover or as a potted plant. This striking new cultivar tolerates full sun to partial shade and can grow to 8 inches tall and 20 feet long. It is shown here with Fan Flower and Purple Fountain Grass, previous Oklahoma Proven selections.

  • Sun Exposure: Full sun to partial shade
  • Soil: Well-drained
  • Hardiness: Use as an annual

 

 

 

Annual for 2001

Mexican Zinnia

Zinnia angustifolia

Several cultivars of Mexican Zinnia are available with white, yellow, or orange flowers that bloom all summer. All thrive in the heat, are mildew resistant, and make excellent 1-foot-tall compact plants for containers, bedding, or edging.

  • Sun Exposure: Full
  • Soil: Well-drained
  • Hardiness: Use as an annual

 

 

 

Annual for 2000

Fan Flower

Scaevola aemula

Fan Flower is an evergreen tropical used as an annual in temperate climates. This low-growing plant carpets the ground with flowers all season long when grown in full sun. It prefers a moist, well-drained soil but is quite drought tolerant once established.

  • Sun exposure: Full
  • Soil: Moist, well-drained
  • Hardiness: Use as an annual

 

 

 

Annual for 1999

Purple Fountain Grass

Pennisetum setaceum

Growing 3’ to 4’ high, this heat and drought tolerant plant blooms all summer until frost. It provides dramatic accent in sunny beds and borders, with purple leaves and bristled flower spikes providing color and texture throughout the season.

  • Sun Exposure: Full
  • Soil: Moist, well-drained
  • Hardiness: Use as an annual