Nasturtiums like poor soil. They have large seeds about the size of a pea. I think they would be great for children to grow. You can plant them in succession over a few weeks and they first put out tendrils with umbrella shaped leaves. When it rains droplets gather on their leaves. Then in late summer, or early autumn the flowers appear. Trumpet shaped, the flower from pale yellow to deep red, with diffeepatterns and stripes as well as full colour ones. You can eat the spicy leaves and flowers in salads or on cold soups. I think the victorians used to use them as food decorations.