Sugar beet, cultivated Beta vulgaris, is a plant whose root contains a high concentration of sucrose. It is grown commercially for sugar production. [Photo provided to China Daily]

Some people dry Chinese toon buds under the spring sun, and then save them for winter.

Apart from Chinese toon shoots, Zhao's mother, who asked to be identified as Tang, sometimes cooks the leaves of other trees for the family, including willows and elms, and even the flowers of acacia trees.

Tang, 54, says she is not good at cooking, and remembers her mother used to cook wild green vegetables that grow in spring along riversides or in the fields, when she was a little girl in Liaoning province.

The most frequently used one was jicai, or shepherd's purse.

Jicai can be eaten both raw and cooked, and its flavor is very pleasant - slightly bitter and sweet.

It can be used to stuff dumplings and steamed buns, or cook in a soup.

Fan Zhihong, a food-safety and nutrition expert at China Agricultural University, says there is apparent scientific rationale for people to have preferences for green vegetables in spring.

"Spring is the season when plants sprout and grow," Fan says.

"Vegetables thrive in spring, and it is the best time for them to have nutrients at the highest levels."

Scientific study has proven that increased consumption of green vegetables is associated with lower risk of diabetes, cardiovascular diseases, some cancers and age-related cognitive decline. Because they are low in calories and have low glycemic and high satiety properties, green vegetables also contribute to weight-control, Fan says.

Besides, green vegetables, especially dark green ones, are low on the glycemic index and rich in phytonutrient, dietary fibers and enzymes, which help people absorb vitamins, minerals and amino acids from other sources, experts say.

Every place offers different choices of vegetables in spring, no matter wild or cultivated, and it is best to eat fresh and local when one can, Fan adds.

In Southwest China's Yunnan, a province famous for producing wild flowers and herbs, spring provides locals with abundant choices for edible greens.

Zhang Jianhui, 28, a chef with a Yunnan restaurant in Beijing, says there are dozens of vegetables in the markets in Dali throughout the spring, which are able to provide a variety of vitamins and fibers to enhance people's immunity and health.