Chimonanthus Praecox Add interest and colour to your garden with this stunning Chimonanthus Chimonanthus praecox, also known as wintersweet, is a vigorous deciduous shrub with an erect trunk and leaves that are 5-29 cm long. Its strongly scented flowers, produced in winter are yellow or pale green-yellow, tepals. However, as lovely as it looks, its' fruits are not edible and its seeds contain a toxic alkaloid called calycanthine, so don't be tempted to test their taste!