How can I care for the Martha Washington geranium which is a bit difficult?
Martha Washington geranium, or Pelargonium domesticum (sometimes called regal geranium) is native to South Africa, so not a hardy plant in our area. There are some tricks to keeping them healthy all year indoors which involves allowing the plants to rest.
A 50 degrees F. environment is the best for the winter rest time when the plant is not in bloom. In winter give only a little water to keep it from drying out completely.They also need a rest period for six to eight summer weeks immediately following the flowering time. During this warm weather rest period give them only enough water to keep the mixture from becoming completely dry. This is a bit tricky, so many people just toss the plant, but with the right care it should survive. It’s the too wet conditions that kill the plant.
In early fall gradually increase amounts of water given, then water moderately, but water thoroughly, then allow the top half-inch of the potting mixture to dry out between waterings. The light requirement for this plant is at least 4 hours of direct sun a day.
Special points: Pinch out the growing tips of young pelargoniums to encourage the development of new side-shoots. And do not neglect to prune older plants every year especially when repotting, because old woody growth will always send out new shoots, pruning can be as drastic as desired.
Hope this helps.
Courtesy of NYBG Plant Information Service