Question: How can I grow Ilex verticillata (winterberry) from the berry (seed)? Answer: In answer to your question about growing Winterberry, Ilex vertillata, you can use the berries from current plants. If the berries are still firm enough, put them in a plastic bag and let them ferment. When soft enough (might take a week) read more How can I grow <i>Ilex verticillata</i> (winterberry) from the berry (seed)?