What is the climate around March and any veg food in Tianjin

For the whole month, sunny & cloudy days are most likely to happen. In early Mar. it is sill a little bit cold, especially at night, so ovecoat, light sweater and jeans are recommended. In the second half of the month, it gets warm, so a leather jacket, thick long-sleeved shirt and regular pants are fine.

Yes, vegetarian food and restaurants are available in the city. I know the Yipintang Veg. Resto at Tongqingli, Ancient Cultural Street, Nankai District. No. 1 Jinmen Veg. Resto at no. 112, Suzhou Road, Hexi District is another good choice.

i am travelling in march mid. What kind of clothing can I take?

If for the mid Mar. 2015, it will be sunny, bu the temperature difference is a little large. I still recommend you bring overcoat, light jacket and jeans. If you are really afraid of cold, bring long john as well.