Harvesting fall rhubarb
My rhubarb is still growing very well. It hasn't had a seed stalk yet. Can I still harvest it? It looks just like it did in the spring. My lettuce and green beans are still producing well. Sept 12, 2016 Jean Siirila
Otter Tail County Minnesota
The harvest season for rhubarb lasts until the end of June. Until then, pick as many stalks as you wish. Then allow the plant to keep all of its leaves, to build its reserves of energy for the next year. A common myth is that the entire plant becomes toxic later in the summer. This is not true; indeed, if a few stalks are pulled on one occasion later in summer to prepare a special dish, plant health and vigor will probably be unaffected. The stalks may be tougher than spring-harvested rhubarb, however.
More info on rhubarb - http://www.extension.umn.edu/garden/yard-garden/vegetables/growing-rhubarb-and-sorrel-in-minnesota-h...
Hope this helps.