Galvanized Fire Ring for Rhubarb Raised Beds?

All of the rhubarb plants are up already, about three weeks ahead of schedule. They came up once already, and got froze back when the nighttime temps went down into the teens.  Now, they have re-sprouted, and in a couple days the temps are supposed to drop down into the low-20's again. So, I'm going to put plastic buckets over them overnight in hopes of keeping them from freezing again.

sanderson wrote:Will the rhubarb expand and fill the rings?

You asked this question back last May, and now I think the answer is "yes they will".  Three of the Rhubarb plants will have to be dug and divided this year since they have spread out and have way too many crowns in each bed. Each bed is 7 sq ft of MM that is 1' deep, and it is a mass of roots and multiple crowns. The other three Rhubarb fire rings are only in their 2nd year, so they have a few years to go.

This Victoria Rhubarb plant has expanded to 12 crowns, and must be divided this fall to get it back down to one crown.

This Victoria Rhubarb plant has 8 crowns, and will be divided this fall as well.

The use of the fire rings to prevent the crown rot problem with Rhubarb plants in our heavy clay soil has been more successful than ever anticipated, so this year I have a new project planned for the fire rings. I am going to add drip irrigation for all of the rings so that they don't require manual watering. This year I removed the old Victoria Rhubarb plants, split the Chipman's Canada Red Rhubarb plant, and transplanted the new crowns into the rings that the Victoria were removed from. I now have three Canada Red and three Gaskin's Perpetual Rhubarb plants in the six fire rings. All of them are sweeter red varieties that are less prone to send up flower stalks. After giving away most of the Victoria crowns, I planted two of them in a flower bed where they will remain for their attractive display.

My plan is to form a circle of the drip tube around the plant, with the tubing about half way between the plant and the edge of the fire ring. The 1/4" tubing has drip emitters spaced at 6", so that should equally moisten the soil without over-watering the plant and causing crown rot. It will take some experimenting to determine how often and how long the drip irrigation will need run, but that will change with weather, too.