American Nurseryman Magazine - Horticulture Magazine and Horticulture Books - Sphaeralcea ambigua - April, 2012 - DEPARTMENTS

American Nurseryman Magazine - Horticulture Magazine and Horticulture Books - April, 2012

DEPARTMENTS

Field Notes: Sphaeralcea ambigua

By John Eustice

Name:

Sphaeralcea ambigua

Common name:

Globemallow

Hardiness:

Zones 8 to 11

Mature height:

24 to 36 inches

Mature spread:

24 to 36 inches

Classification:

Subshrub

Landscape Use:

Floriferous and low- maintenance, best used in arid-region gardens

My first introduction to native globemallow came in the form of some volunteer seedlings in the alley behind my Tucson home. Globemallow, or Sphaeralcea ambigua, is everywhere in southern Arizona; gardens and waste places as well as unspoiled natural habitat. Globemallow can bloom year-round, but it flowers most abundantly in the spring. Forms with orange flowers are especially common, but lavender, hot pink, red and other colors are seen. This shrubby perennial blossoms all along its dozens of wand-like stems. Hundreds of flowers about an inch in diameter cover the plants. Its gray-green leaves are deltoid and have three lobes. Globemallow appears lush, and it helps to soften the more rigid forms of cacti and succulents while thriving in the same tough situations.

The plant size varies from ankle to waist-high depending on the growing conditions. Globemallow does well in Tucson on natural rainfall. Plants that get more water are taller, but they're also are more prone to lodging in windy weather. I learned this the hard way recently, when some over-sized plants got knocked flat. In extreme drought or very dry areas, watering is a good idea. Our native soils suit this plant well.

Sphaeralcea ambigua is at home in caliche soils, like mine, and in other demanding situations. It is also fully cold- and heat-tolerant throughout much of our region. In my garden, plants maintained active growth despite temperatures in the high teens during February of 2011. Full sun is ideal, even in the hot deserts, although the light shade cast by desert willow, velvet mesquite or paloverde is also acceptable.

Globemallow is low-maintenance. Pruning clumps to the ground in fall helps tidy up this cool season grower. Plant from containers in the autumn or winter and irrigate until established.

Plants seed abundantly in my garden, but they are never unwelcome. Germination is prolific during the summer rainy season. Seed propagation is likewise easy for nurserymen and gardeners needing a few more plants. They grow well both in the ground and containers. A porous medium, like that used for cactus, works well. Stock grows fast with modest moisture and nutrition.


Courtesy of John Eustice

Sphaeralcea ambigua is a standout among arid region perennials. It is colorful, floriferous and extremely well-adapted. This Southwestern native has caught the eye of wildflower enthusiasts, plantsmen and gardeners with its inherent toughness and beauty. Globemallow tops my list of Southwestern landscape plants.

John Eustice
Freelance garden writer
jaeustice@gmail.com