The regal or Martha Washington geranium has long been a popular pot plant for the early-spring market and you will see many of them on display in garden centres and retail shops around Valentine’s Day, Mother’s Day and Easter. They produce a wondrous show of bloom — the individual florets of a regal geranium are much larger than those of other pelargoniums so the flower heads are quite striking. Some newer varieties are called pansy faced because the individual florets resemble pansies, even having the telltale pansy blotch on each petal.
While the regals have long been popular seasonal pot plants sold for special occasions in the spring, there is an increasing interest in growing these plants in our outdoor gardens. They do make a spectacular show, but there are some drawbacks. The most significant handicap to having Martha Washington geraniums in the outdoor garden is that they are not continuous bloomers like other bedding pelargoniums. They bloom for four to six weeks maximum and then they have to be coaxed back into bloom, which is not an easy process. However, as they are generally grown as container plants, when they finish blooming in the outdoor garden they can easily be replaced with other container plants.
Getting a regal geranium to rebloom requires rigid manipulation of light, water and temperature. Bud initiation will occur only if night temperatures are quite cool and daytime temperatures are kept low as well. The plant also requires at least 14 hours of bright light to set bud — and the light must be intense — that is, the intensity of full sunlight. Finally, water must be withheld so that only enough water is given to prevent wilting. It appears that the plants only initiate bloom when under stress and if treated too kindly — too much fertilizer, too much water, and warmer temperatures with shading from the sun, they will produce lots of vegetative growth but no bloom.
Of course, like other pelargoniums, the Martha Washingtons are not tolerant of frost and must be moved indoors if they are to be overwintered. Unless you have a cool sunroom or all-season greenhouse, you will have difficulty wintering a regal geranium. It will not be happy in the warm temperatures of the average house and there will not be enough light to encourage it to set bloom.
Luckily regal geraniums are available at very reasonable prices during the spring and so one can buy the plants with the idea that they will be discarded after they have finished blooming. If you received one for Easter, be sure to water it regularly. Watch for white fly pests, and ensure the pot does not sit in water. If you are prepared to create the specialized conditions necessary to bring the plant into bloom again, then do so. Otherwise, this might be one plant that fits the “disposable plant” category, and will be relegated to the compost bin after it has finished blooming.