Martha Washington Geranium

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 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. 

Martha Washington geraniums have somewhat ruffled leaves in a bright green shade. The edges are often toothed, and leaves release a citrus fragrance when crushed. 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. 

These pretty bloomers grow best when air temperatures are below 60°F. Martha Washington geraniums set their flower buds when night temperatures hover in the 50- to 60-degree range. As a result, they’re popular as spring plants, most often bought as gifts for spring holidays, such as Easter or Mother’s Day. Once summer temperatures arrive, plants usually stop flowering. If you like the look of Martha Washington geraniums and live where summer brings on some sizzle, plan to pull plants out of pots or planting beds as heat arrives and replace them with traditional garden or zonal geraniums. 

Martha Washington geraniums prefer fertile, well-drained soil. In landscape beds, amend soil with plenty of organic matter prior to planting. In containers, use a commercial soil-less mix developed for use in planters. These mixes provide the right drainage for plants in a container to thrive. Martha Washington geraniums are susceptible to root rot, so avoid overwatering plants or tucking them into heavy clay soils in planting beds. 

Place your Martha Washington geraniums where they’ll receive direct sun, but protect them from hottest afternoon sun in all regions. If plants don’t get enough sunlight, flower numbers drop. Encourage flower formation by removing spent blooms. This also helps reduce fungus development on rotting blooms. If you see any signs of fuzzy mold-type growth (botrytis) on Martha Washington geraniums or orange or brown spots on leaves, remove affected plant parts and destroy them. 

Avoid using high-nitrogen fertilizers on Martha Washington geraniums. Instead, select a bloom booster-type fertilizer that helps promote flower formation. A high potassium fertilizer developed for vegetables works well, too. On the fertilizer bag, the first number, which represents nitrogen content, should be no more than half of the other two numbers. For instance, a fertilizer labeled 10-10-10 isn’t the right type to use. Instead, use one labeled like 4-8-10, which is typically a flower and/or vegetable fertilizer, or 2-4-1, a typical fish-based plant food.