He died of heart attack in 1975 so far as I can find out.

"Fun Ways to Eat and Cook Rhubarb

You can eat our bright red stalks but not our green leaves which contain an acid that should not be eaten. Simply cut off our leaves and any white root area, then cut stalk crosswise into 25-50mm lengths. There is no need to peel."

I like to eat the stalks raw but dipped in sugar bite by bite.