In Grow a Garden, crops are one of the main features of the game, which are planted as seeds.
Seeds can be obtained from the Seed Shop, Seed Packs, Pets, Events, through Crafting, and more.
These seeds will grow into plants of different appearances, sizes, and values.
Crops can also obtain mutations from weather and admin events, which will sell for more.
This article contains a Rhubarb wiki in Grow a Garden, including its crop/seed price, whether it’s multi-harvest, and more.
Grow a Garden Rhubarb Wiki

The Rhubarb is an uncommon crop that was added in the Cooking Update.
You can get it as a reward from the Culinarian Chest or Exotic Culinarian Chest at a 34.5% chance.
The crop is multi-harvest with a minimum value of 13,538 Sheckles.
It has a minimum value weight of 1.90kg, a base weight of 2.00kg, a minimum weight of 1.40kg, and a huge chance of 1.25%.
Further reading
Grow a Garden Spring Onion Wiki