Shallow tillage will incorporate the fertilizer. Remove flower heads as soon as they appear in the spring. Pests Only one disease of importance is found on rhubarb in Western Canada. Red leaf disease of rhubarb commonly attacks the roots and crown areas of the plant. The leaves of the affected plants become reddish and later wilt and shrivel.
New leaves cease to appear, and all that remains of the plant above ground is a few dry leaves.
In some plants this process is slow, while in others it is rapid. Examination of the parts below the ground reveals decay in varying amounts. With plants showing only reddening of the leaves, the roots may appear normal on the outside, but their centers will be found to have rotted away. Some rotting in the crown will also be evident. In more advanced stages, when the leaves become dry, the greater portion of the root and crown will be found in a decaying condition.