Unripe Chinese dates (Ziziphus jujuba) growing on a tree. Chinese dates have been grown in China for 4,000 years. The tree can grow to 6 metres high and it produces its fruit during late spring. The fruit, which are rich in vitamin C, can be eaten once they turn red. The fruit is believed to have medicinal properties and one of its most popular uses is as a tea for a sore throat.