i planted hollyhocks 6or7 years ago ( I live I MN. The seeds are from IA.) The seeds were multiple colors but now are a dark purple almost black & since blooming have been that color is there any way to get more colors out of the plants.
Hennepin County Minnesota
This happens with many self-seeding plants. There are a couple of possible reasons, but there is no way to get these to change colors. If you want more variety you will have to plant new plants or seeds.
If they were hybrid plants, new plants from seeds will not come back the same as the initial plant. Like humans, each one will represent its parents a little differently.
Hollyhocks are biennials, which means they grow only leaves the first year. The next year they grow leaves and flower. After blooming that plant dies. The purpose of flowers from the plant’s point of view is to produce seeds. The seeds produced grow the next year, so while it may seem like you have the same plants you purchased, you actually have several generations out from those plants.
Sometimes other colors have not been able to re-seed. This could be caused by the other seeds genetically not being as strong, they were eaten by animals (as flowers or seeds), they fell in less than optimal locations, or even the flowers that are deemed prettier are picked for bouquets and the less-favored left to reproduce. Whatever the cause, the only solution is replanting.