Cooked rhubarb with it's high acidity and added sugar syrup will last a long time refrigerated, even without canning. Of course, canning is a good way to take advantage of fruits and veggies when they're abundant. My grandma had a perennial crop of rhubarb in her Denver garden and I grew to love the sauces, pies, syrups and jams that she made from it. I imagine she might have made rhubarb liqueur too, but she wouldn't have told anyone, or labeled the bottles. Nana was a closet sipper who re-bottled rum into plastic containers so it wouldn't look like she kept alcohol in the house. She lived through the Great Depression and her experiences led her to build a large basement cold cellar room filled with home canned goods.
We picked up a couple 3 qt. jars and added to the rhubarb cordials in making. One is dry with tequila only, no sugar yet, one uses vodka with Grand Marnier and sugar syrup, and another is with rum and triple sec with sugar syrup. We'll see how they come out in a few months.
http://i59.photobucket.com/albums/g2...psbvqywqxz.jpg
BTW, I have neighbors here in the mountains who have rhubarb plants that I know are more that 35 years old. It's a trouble free and abundant food producer. And, I've never seen evidence that wildlife eat it.