Annuals Gardening Hybridizing Saving seed

Why Are My Pansy Flowers Shrinking?

By Larry Hodgson

Question: I’ve been saving and resowing the seeds of my pansies. Three years ago, they had big flowers, but year after year, as I resow them, the flowers are becoming smaller and smaller. Even the flowers of pansy plants that germinated sprouted all on their own are smaller. What’s going on?

Leonard Carmen

Answer: This is a well-known “problem,” if you want to call it that, and the answer can be found in the genetics of the pansy.

The garden pansy (Viola × wittrockiana) is a complex hybrid developed in the 19th century using three species of Eurasian origin: V. lutea, with yellow flowers, V. altaica, with purple flowers and especially the so-called wild pansy or Johnny jump up, V. tricolor, with purple, yellow and white blooms. The garden pansy differs from its ancestors in being a larger plant with much larger flowers and it also comes in a much wider range of flower colors.

Wild pansy in bloom
Within a generation or two or three, most garden pansies will have returned to a form similar to the wild pansy (Viola tricolor), seen above. Photo: H. Zell, Wikimedia Commons

However, if you collect seeds from a garden pansy or allow it to self-sow, which, by the way, it will readily do, it tends to revert over two or three generations to the appearance of a wild pansy, usually V. tricolor. And it’s not just the size of the flower and the plant that decrease, any special coloration of the hybrid (reds, oranges, etc.) tends to disappear and the plant reverts to roughly the original purple, yellow and white trio of V. tricolor.

To maintain large flowers in an interesting range of colors, companies that produce pansy seeds make crosses between specifically selected varieties … and don’t share the parentage of their hybrids with home gardeners. If you want to maintain the effect of large-flowered pansies in your garden, therefore, you’ll have little choice other than to purchase pansy seeds of your preferred color and form on a regular basis.

Of course, this situation is not limited to pansies. Many hybrid plants “degenerate” when allowed to self-sow generation after generation and return to an appearance closer to the ancestral form.

To learn more about pansies, read the article The Year of the Pansy.

4 comments on “Why Are My Pansy Flowers Shrinking?

  1. That is why self sown nasturtiums are only orange or yellow.

  2. It is possible that you can purchase pansy seeds that will reproduce true to the flower you planted. Just check the seed companies that sell openly pollinated seeds, sometimes called heritage (incorrectly). If they sell pansy seeds, you’ve got a solution to buying new plants each year.

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