G'day!  When I was young we grew rhubarb in the farm garden . From memory in a fairly sunny spot, but sheltered from strong wind.

Now - maybe 70 years on - we have a couple of plants in a raised garden bed.

From little plants they grew produced stems maybe 8 inches from the corm to the start of the leaf.   Rhubarb and Apple pie -  Yum!

Now as we get into our Autumn [or Fall] the stems are much shorter, and the plants a lot less vigorous.

Is this just normal for the colder nights and days in the low 20's C. - or should they be fed some nitrogenous fertilizer like sheep manure?

Any helpful thoughts most welcome.