by OCMGA Master Gardener Tom Wentzel
This is my first rhubarb harvest this year. There was one more, but I ate it. We all have bunches of recipes for using rhubarb so I won’t go there.
Chinese records from 2700 BC record its medicinal use. Marco Polo documented its use, but I’m not sure if he introduced it to Europe. A while ago, I visited Old World Wisconsin. In one of the Germany heritage houses there was a string of, what I thought, were chicken bones. It was dried rhubarb! Many of the historical uses that I have read seem to be medicinal, rather that culinary.
My first picking didn’t have that lip puckering sourness of later season harvests. The sourness is due to the pH (acidity) which is in the range of 3.1 – 3.2. For reference, fresh lemon juice has a pH of about 2. Adding sugar doesn’t “neutralize” the acidity, it simply covers it up.
Rhubarb leaves have a reputation as being toxic. This is due to the relatively high concentration of oxalic acid. Oxalic acid’s primary effects can be stomach irritation and kidney problems. Ten pounds of leaves would be required to deliver a lethal dose. Kitchen pot cleaners such as Bar Keepers Friend and ZUD use oxalic acid as the primary active ingredient.
Uses for Rhubarb leaves:
- Use them as a mulch.
- They can be composted in limited quantities.
- GREAT for leaf castings
- I have seen recipes for rhubarb leaf concoctions as insecticides and repellents. These have been anecdotal, their effectiveness has not been verified.
I will break my promise not to talk recipes. Here’s mine: Peel, then eat.