Botanical Name: Pelargonium domesticum
Martha Washington geranium gets its name from a once-popular cultivar. Although newer Pelargonium hybrids outshine 'Martha Washington', the name stuck. Today, that early cultivar has been replaced by more vigorous hybrids, with a wide range of spectacular flowers to choose from. These hybrids are also commonly known as Regal Geraniums.
This is a large group of complex hybrids. All have naturally branching stems and dark-green, crinkled leaves. Thick, succulent flower stems bear upright clusters of flat-petaled flowers. Geranium colors include white, pink, red, maroon, salmon and purple -- in many captivating combinations. The top 2 petals often have a bolder color or a contrasting pattern.
You'll find these hybrid geraniums for sale in late winter, when they're in bloom. Many good varieties of Pelargonium domesticum are available to choose from. Here are a few...'Maiden' varieties are compact, making them ideal for a sunny windowsill. 'Pompeii' is another compact plant, featuring stunning, nearly black petals edged in white. 'Carisbrooke' has big, pink flowers splashed with dark red.
Martha Washington geraniums bloom in late winter. If you're growing geraniums indoors, you'll need to give them a little help with the seasons...a rest in summer and a cool autumn will make them set flower buds.
After following the steps above, you should see flower buds midwinter, and enjoy beautiful blooms in February or March.
Origin: South Africa
Height: 1-2 ft (30-60 cm)
Light: Bright light
Water: Water thoroughly, and allow surface of soil to dry between waterings. Cut back on watering after flowering, but don't allow the roots to dry out completely. Brown spots on leaves are caused by a fungus. Cut off affected stems and leaves. Treat your plant with a fungicide if needed.
Humidity: Average room humidity.
Temperature: Winter through summer, normal room temperatures (60-75°F/16-24°C). In fall, 2 months of cool nights (50°F/10°C) will trigger flower buds.
Soil: Peat-based soilless mix.
Fertilizer: Feed every 3 weeks fall through spring with a high-phosphorus liquid fertilizer diluted by half.
Propagation: Take stem cuttings in spring and root in fresh potting mix.