May 5, 2011

A Giant Amongst Geraniums

It's hard to believe that this giant is a true geranium ( not a Pelargonium), but this is a plant that even surprises the plant geeks, for it is one that we all rarely see in bloom, since it is notoriously fussy about flowering. Geranium maderense is a giant in a genus where most plants live in window boxes, for this is a plant that will require an old bath tub, or a big spot in the garden if you live in California ( it is tender, and must be brought indoors where there is frost). A Biennial, this plant takes some time to mature, perhaps two or three years, then it will bloom, if you are lucky, in a massive display of 6 foot tall stems and hundreds of flowers. The type plant is magenta, this one is a white ( alba) form that I started from seed.

Geranium maderense gets its name from where it grows, on the island of Madieira, an island off of the coast of Portugal. Like many plants that find their way to isolated islands, like Lobelia, the evolutionary changes that occur in these situations can take a tiny plant, and evolve them into trees. Although G. maderense is no tree, it sure comes close with a thick, woody trunk, and three foot long leaves and petioles radiating out. This is a one-of-a-kind geranium species. Looking for one? Try Annie's Annuals, I believe that they offer the pink form. My seed for G. maderense alba 'Guernsey White'  came from Jelitto seed.

The flowers on G. maderense are large, like silver dollars with just a touch of pink, which was surprised me, but you really only notice the tint in photos.

The leaves are large, with the leaf petioles extending two to three feet out in all directions. My plant is potted in a large clay tub, 40 inches in diameter.


  1. What a marvelous geranium Matt. It is a big one isn't it? Very pretty.

  2. Anonymous7:33 AM

    Here in eastern Massachusetts, a couple of falls ago I goofed and left my G maderense outdoors, in the ground. The temperature dropped to 22F, a good, hard freeze, no snow cover. The next day I hacked it out of the icy ground, threw it in a pot, and it survived quite nicely.

    One side effect is that it now has two crowns, so it might be worth dividing. Then there's the task of finding a 30" pot like yours...

  3. Glad to see your G. madarense bloomed. Have you noticed the fragrance. I have a friend who has a not very nice way to describe it but I have never really noticed it personally.

    I grew one in a huge pot on my balcony when I lived in Santa Monica. It is pretty neat to see how quickly and thoroughly they collapse and die after blooming and setting seed.

  4. I'm always amazed at what you get to bloom in your greenhouse! The G. maderenses are still flowering all over the place here in San Francisco :)

  5. Fabulous! Such an astonishing display! I had read they were monocarpic...have you found that to be the case?


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