There is nothing rare about Geranium maderense but it is certainly eye-catching if you have not seen it before. The only tricky part seems to be getting the first plant to grow. It then sets seed prolifically and it will continue coming up for years to come. I weed out most of them, leaving two or three to grow on to flowering size each season.
This is the largest of the geranium family and it is biennial. It doesn’t flower until its second year and then it puts on a huge show, sets seed and dies. By this point it is at least a metre high and a metre across so it does require space. Curiously, its lower leaves (which are large and attractive in their own right) become elbows resting on the ground to enable the plant to stand upright without support when flowering time arrives. It comes from the island of Madeira and to save you looking it up, this island group belong to Portugal and is located southwards to the west (or left) of North Africa. So this geranium comes from a hot, dry, maritime climate and is not particularly hardy to cold areas but it seems to be resilient in a range of soil conditions.
Apparently the Romans used to call Madeira the Purple Isles which seems appropriate given the most common form of G. maderense is in cerise to purple tones. There is a white form available. Terry Hatch from Joy Plants on the northern border of the Waikato gave us three plants of the white form but, alas, they failed to survive with us. This may be because we didn’t get around to planting them out quickly enough though others have told me they have tried and lost the common purple form too. If you are going to try growing G. maderense, go for a position which offers warmth, sun, good drainage and space.
First published in the Waikato Times and reproduced here with their permission.
Postscript: I have just been alerted to the existence of an endangered geranium in Hawaii which would almost certainly beat G. maderense on size. Geranium arboreum can reach up to 4 metres high, though it does not appear to be as showy in bloom as the second place-getter in the big geranium stakes.