Jenny Harris, of Balclutha Primary School, asks :-
Three seeds on one of my strawberry plants seem to have sprouted. What causes this?
Geoff Langford, a crop scientist with Berryworld, responded.
There are several possible explanations for this occurrence. The first is a group of diseases called Phytoplasmas that can be spread from a range of plants by plant hoppers. This can result in seeds sprouting leafy growths as shown in the attached photo. The second possibility is a non-infectious symptom similar to this that seems to result from an unusual combination of circumstances (including climatic factors and plant nutrition), that causes a hormone imbalance in the fruit.
I had a case involving blackberries this season where a similar secondary growth occurred. Strawberry seeds usually need to have acid treatment in order to germinate (passing through the stomach of a bird is how this occurs in nature). I think it unlikely that it is a germinating seed, but more likely that instead of developing as a normal seed, it has developed as a leafy growth because of one of the two reasons outlined above.