"Space crops" are grown from seeds that have spent time in orbit, where they are modified by cosmic radiation, or future generations developed from those seeds.

Shi Zhenggang, deputy general manager of Pujiang Town Zhengyi Horticulture Co Ltd, said his company planted 25 species of space crops, including tomatoes, corn and watermelons, in February. The seeds had been shot into space on a recoverable satellite last year.

"Space crops are generally bigger than common crops and the color of some species varies," Shi said, citing watermelons with yellow skin as an example.

He said the output from space seeds is 25 percent higher than regular seeds on average.

Crops from the company's first harvest will be sold in a variety pack containing a few species of crops for 100 yuan (US$13) to 150 yuan a box, Shi said.

The next harvest is expected in two months.

Feng Zhiyong of the Shanghai Academy of Agricultural Sciences said space crops don't pose any risk to people's health as changes in the seeds happen spontaneously when they come in contact with cosmic radiation, which is different from genetically modified food.