Marketmen said low supply and high demand mainly held prices continuously in green zone from past four trading seasons.
Reports of lower production than expected this year further influenced the sentiment.
At the National Commodity and Derivatives Exchange counter, castorseed prices for February contract hardened by Rs 57, or 1.23 per cent, to Rs 4,691 per quintal, with an open interest of 1,64,490 lots.
Current January contract improved by Rs 43, or 0.94 per cent, to Rs 4,605 per quintal, in an open interest of 41,170 lots.