Expand your geranium horizons with the cool-season member of
the family: Martha Washington geranium (Pelargonium x domesticum). Also known
as regal geraniums, this group of geraniums features richly colored blooms with
petals that resemble velvet. Petals have a lovely ruffled effect that enhances
the plants’ luxurious feel. The edges are often toothed, and leaves
release a citrus fragrance when crushed.
The color range on Martha Washington geranium flowers falls into red-purple shades, including lavender, pink, burgundy and purple. White also appears in the blossom mix, along with a host of wonderfully-painted bicolor blooms. Two common patterns are solid petals with white edging or white centers.
Overall, Martha Washington geraniums grow roughly 12 to 18 inches tall and 12 to 24 inches wide. The flowers appear in clusters similar to zonal geraniums, but stems tend to be shorter, making a Martha Washington geranium frequently appear to be overloaded with flowers.
With their colorful blooms and showy foliage, Martha Washington geraniums (Pelargonium domesticum) are a garden favorite. These beauties grow well in U.S. Department of Agriculture plant hardiness zones 5 through 10 but do best in areas that have warm days and cool nights. You can use the plants to create a beautiful display along borders, in patio containers or in hanging baskets.
Light and Temperature
Martha Washington geraniums require six hours of sun each day. If they receive less than that, the plants tend to get leggy and may not bloom profusely. Although the plants prefer full sun, it’s best to keep them out of intense midday sun in the summer to prevent the leaves from burning. The plants bloom when nighttime temperatures range between 50 and 60 degrees Fahrenheit.
Planting and Soil
Martha Washington geraniums grow in a wide range of soil types but do best in rich, well-drained soil. If planted in garden beds, space them 8 to 12 inches apart. If planting your geraniums in a container, choose a potting soil with peat and vermiculite as the main ingredients. Choose a pot that is at least 8 inches in diameter and has drainage holes in the bottom or sides. To avoid leaving your geranium in standing water, use a pot without a drainage tray.
Feeding and Watering
To promote flowering and to keep your plant healthy, feed your Martha Washington geranium every two weeks. Fertilizer with too much nitrogen will encourage leaf growth rather than flower production, so check the numbers on the label. Choose a fertilizer with the first number being no more than half the other two numbers – for example, 4-8-10. Follow all package directions regarding how to apply the fertilizer. Martha Washington geraniums prefer moist but not wet soil. To keep the soil from getting too wet, only water when the top 2 inches of soil feel dry to the touch.
When the flowers of your Martha Washington geranium die back, trim off the spent flower heads. This will encourage the plant to produce more blooms and helps prevent disease from the rotting blossoms. Any plant that shows signs of fungal disease, such as powdery leaves or leaves with small orange or brown spots on them, should be removed from the garden and destroyed. Pests are rarely a problem with geraniums, but if geranium budworms appear on your flower heads, pick them and their eggs off immediately.
In mild winter areas that don’t experience long periods of freezing temperatures, geraniums can be kept in the ground as long as you mulch them heavily with compost or leaf litter. A more reliable winter option is to take cuttings from your plants in the fall and plant the cuttings in rooting mix. The cuttings can then be raised indoors until spring. If you like, you can also dig up the entire plant and bring it indoors. Geraniums overwintered indoors should be kept in a bright location.