what about misting.I know the shade cloths would help with keeping the soil cooler& i'd think good air flow would also.How far is that river?have you checked further down in valley to see if temps are lower than where your at?higher ground has higher temps

I might try growing some again and see what gives.I know it'll be gone by june.I lose it when stay in the 80s(28),but know they mist it in the stores for keeping fresh