my rhubarb is in the ground and grows great, it is in sun in the afternoon and gets lots of rain water and I often feed it with sea sole

ours grew really well semi shade of established trees in our courtyard. If you have dogs, take care as it is toxic to them x

it likes semi shade. if you have a dog, keep them away from it as it is toxic for them

wow that last answer was so detailed! i was just going to say, make sure that the soil has the nutrients it needs lol

Rhubarb needs well drained soil. Black pots absorb heat and the plants then suffer from heat stress in very warm / hot weather. If the plant touches against the sides or top of the pot they may be getting burnt. If it sends up a stem in the middle of it it is most likely its flower which should be removed as it takes all the nourishment from the plant. If the pot is too close to a fence it may be absorbing heat reflecting from it and scorching the plant. It may need fertilizing. I suggest you contact a Garden Centre. You may get information by googling Rhubarb. The pot may not be a suitable size either. If you only planted it recently you may have planted it at the wrong time of the year. If you live in a very humid area it could also have a disease or virus in it.