Heat Wave

A scorching sun. Sweltering humidity. And temperatures spiking well beyond your comfort level. Summer is on its way and it’s bringing the heat. But when you feel like you’re dying, these plants will be thriving. Greenhouse Management talked people in the industry and the experts at the Dallas Arboretum and Botanical Garden about these 12 drought-tolerant plants, guaranteed to survive even a heat wave in the south.
 

Gomphrena
Easy and fast-growing, this plant’s color can last even through the hottest Texas summer. The Dallas Arboretum and Botanical Garden recommends the ‘All Around Purple’ variety from Sakata, a tall, large-growing gomphrena with a searing purple. For something more grower friendly and shorter for shipping, there is the ‘Audray’ series from American Takii and the ‘Las Vegas’ series from Benary. Both retain great garden performance. There is also PanAmerican Seed’s G. ‘Fireworks,’ which quickly grows to 3 feet in flower and is able to withstand high winds, torrential floods, drought and high and low humidity.

For more: www.sakata.com, www.takii.com, www.benary.com, www.panamseed.com

Portulaca
Is there a plant more drought-tolerant than Portulaca and Purslane (Portulaca oleracea)? In fact, too much water can be lethal. The new ‘Happy Hour’ series from PanAmerican Seed is one of the “rose moss” types, and will bloom consistently and earlier in the season. Of the flat-leaved purslane types, both the ‘Rio’ series from Ball FloraPlant and ‘Pazazz’ from Danziger have great flowering. But if you’re looking for something that can survive in a hanging basket through a Texas summer and grow to 3 feet, then the Dallas Arboretum and Botanical Garden recommends the ‘Samba’ series of Portulaca grandiflora. The ‘Samba’ has huge, blousy flowers of fiery fuchsia, glowing white or the bicolor version.

For more: www.panamseed.com, www.ballfloraplant.com, www.danziger.co.il

Gaillardia
The vegetative ‘Galya’ series in the ‘Spark’ colors from Danziger produce large, double-flowers from April until November, lasting until a hard frost. Most of the varieties are vigorous and quick, and form a well-branched plentiful compact bush. If you’re looking for a seed-grown variety, the Dallas Arboretum and Botanical Garden likes the Gaillardia pulchella ‘Razzledazzle’ from Thompson & Morgan. It is a large plant but produces flowers up to 3 inches in diameter and works well for borders, containers or as a cut flower.

For more: www.danziger.co.il, www.thompson-morgan.com

Zinnia haageanea
Recent breeding may be focused on the Z. marylandica hybrids, but the Mexican Zinnia (Z. haageana) is exceptionally drought-tolerant and also resistant to powdery mildew. Dallas Arboretum and Botanical Garden says the ‘Persian Carpet’ from Benary Seed and ‘Aztec Sunset’ from Thomspon & Morgan were able to withstand the brutal Texas heat and never showed signs of the disease. ‘Persian Carpet’ blooms double and semi-double 2-inch bi-colored flowers and grows to 26 inches in height. A winner of a FleuroSelect Gold Medal, ‘Aztec Sunset’ is a floriferous, dwarf, bushy plant that produces double flowers in several shades, including many bi-colors.

For more: www.benary.com, www.thompson-morgan.com

Otomeria
The ‘O’premiera’ series by Danziger is a new vegetative propagated genus to ornamental horticulture. It has sturdy mounding stems that produce flowers that appear as a cross between Pentas and Phlox. Dallas Arboretum and Botanical Garden found the ‘Baby Pink’ variety to be the best performer of the four varieties, but they all held up to heat and drought exceptionally.

For more: www.danziger.co.il

Lantana
Most likely the best selling plant in the south is the classic ‘New Gold’ variety. The ‘Lucky’ series from Ball FloraPlant has a good compact habit, especially ‘Pure Gold’ and ‘Pot of Gold.’ They have a controlled mounding habit and stay upright. They are also well-branched, requiring fewer pinching and PGRs. For a larger trailing type there is the ‘Luscious’ series from Proven Winners in ‘Citrus Blend,’ ‘Grape,’ ‘Tropical Fruit’ and ‘Lemonade,’ maintaining a strong habit and color throughout the summer.

For more: www.ballfloraplant.com, www.provenwinners.com

Helenium amarum
The ‘Dakota Gold’ from PanAmerican Seed is a Texas native yellow composite that thrives in heat. The hotter the temperature the more it blooms. Strong-growing and compact, ‘Dakota Gold’ should be grown during long days for the best habit and vigor. No worries on it becoming a creature’s dinner, as it is highly resistant to animals, including deer and rabbits. Although it is not commonly used, it cannot be beat in dry soil and hot weather.

For more: www.panamseed.com

Chrysocephalum  
With silvery foliage that is accented with orange or yellow buttons, this genus is a mounding plant that is perfect for containers, baskets or mass planting. Both the ‘Flambé’ series from Proven Winners and the ‘Silver Fox’ from Ball FloraPlant do well through heat and drought, and are surprisingly cold hardy too, having been able to survive and flower through temperatures in the mid-20s. ‘Flambé’ has a trailing habit and trails up to 24 inches. It is also tolerant of sandy soil. ‘Silver Fox’ is well-branched and compact, getting up to 7 inches in height and 18 inches in spread.

For more: www.provenwinners.com, www.ballfloraplant.com

Dorotheanthus
The vegetative annual ‘Mezoo,’ from Syngenta Flowers Inc., grows like kudzu and is great for a hanging basket. The variety has variegated foliage accented with bright burgundy red stars and lasts all summer long. Greenhouse growers should use 4-inch pots, quarts, 6-inch pots and baskets. Pinching is recommended, but it does not need growth regulators and does not have any significant pest or disease problems.

For more: www.syngentaflowersinc.com

Euphorbia
Jimmy Turner of Dallas Arboretum and Botanical Garden says he wouldn’t design a color bed or container without this plant. Don’t let its delicate, frilly appearance fool you – its flowering flourishes as the temperature rises and, once established, can survive with water only once or twice a week. Turner’s personal favorite is ‘White Manaus’ from Athena Brazil, growing 3 feet across. It has dark green foliage with petite white flowers and goes well with Poinsettias. Its rooting time is three weeks or less, doesn’t require regulators and may need one to two pinches. For smaller varieties suited for greenhouse culture there is the ‘Diamond Frost’ from Proven Winners and ‘Breathless’ from Ball FloraPlant.

For more: www.athenabrazil.com, www.provenwinners.com, www.ballfloraplant.com

Heuchera
With its large, glossy, purplish leaves, short stems of white flowers and a dense mounding habit, the Heuchera ‘Creole Night’s by Terra Nova Nurseries makes for a great landscape plant. In addition to being tolerant to drought, heat and humidity, it is attractive to butterflies and hummingbirds. It is hardy in USDA Zones 4 to 9 and needs to stay moderately dry between watering.

For more: www.terranovanurseries.com

Echinacea
Producing pale yellow petals around orange cones, the Echinacea ‘Aloha’ from Terra Nova Nurseries blossoms all summer until the first frost. It has an upright habit and is hardy in USDA Zones 4 to 10. This fragrant flower is also deer resistant and can be used as a cut flower. The plant should be kept moderately dry between watering.

For more: www.terranovanurseries.com