(Solanum dulcamara) Zones 4 - 8. Bittersweet succeeds in full sun to light shade. If being grown for its medicinal uses, the plant is best placed in a dry and exposed position. Sow seed in the spring in a cold frame. When large enough to handle, prick the seedlings out into individual pots and plant them out into their permanent positions in the summer. The seeds may also be planted in the autumn in the prepared garden bed.