Vivipary is the premature sprouting of seeds inside the fruit and is more likely to happen when abscisic acid (ABA), a plant hormone that regulates seed dormancy and germination, is reduced. Vivipary is not uncommon in overripe or very vine-ripe tomatoes and tomatoes stored in the refrigerator where exposure to cool temperatures and low light are thought to inhibit ABA. Environmental conditions such as potassium deficiency and over fertilization with nitrogen are also thought to influence vivipary. In addition, some types of tomatoes (cultivars) are more prone to vivipary indicating that genetic factors may play a role. While tomatoes undergoing vivipary may not be very appealing or tasty, they are safe to eat.

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