A canopy treatment system to treat plants is disclosed. In one implementation according to examples of the present disclosure, a canopy treatment system comprises a hot fluid generating system configured to heat a fluid, the hot fluid generating system including a canopy valve; and a canopy in fluid communication with the hot fluid generating system, the canopy defining a treatment region, the canopy valve of the hot fluid generating system selectively positionable to control fluid flow between the hot fluid generating system and the canopy.