Answer: In your climate, geraniums are annual plants. The wild geraniums you found growing in their spot were probably the weedy cranesbill called Herb Robert. These plants grow from seeds which are either blown into areas by the wind or dropped by birds. Seeds of a propagated geranium will not produce a wild geranium.
The common name 'geranium' is widely used for Pelargonium, but botanically speaking, it is not really accurate. To the botanist, pelargoniums are woody-based perennials (most of them native to South Africa) that endure light frosts but not hard freezes and have slightly asymmetrical flowers in clusters. True geraniums are annuals and perennials native mainly to the Northern Hemisphere, bearing symmetrical flowers either singly or in clusters.
Cranesbill is Erpodium reichardii. While it is similar in appearance, and a member of the Geraniaceae family, it is not really considered a Pelargonium.
Hope this clarifies things for you!
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