As the name indicates, sea pea grows along the sea shore. In the Netherlands, you find it mostly growing between basalt blocks on the foot of sea dikes. Elsewhere, it grows on stony beaches, steep beach ridges or other such shores. The seeds are spread by the sea, remaining fertile up to five years. In that way, the plant can spread throughout the world. Once the hard seed covering is abraded by sand, the seed will germinate. The major part of the plant is hidden underground. The plant rarely gets the chance to fully flower in the Netherlands, due to harsh conditions and people's tendency to pick the lovely blossoms.