STOCKTON, Calif. (KGO) -- Big clumps of water hyacinth are blocking the Port of Stockton.
City officials are at a loss of what to do.
The floating plant is forcing ships to anchor in the delta and has completely shut down night time traffic because a ship's radar can't distinguish between hyacinth and boats.
The hyacinth has been sprayed with herbicide, but it's still there.
City officials are afraid they might have to wait for a winter freeze to kill the hyacinth off.