Agriculture Reference
In-Depth Information
ted. After about six weeks, these new plants can be planted out. Rhubarb can be planted anytime from
spring to autumn.
Propagating by seed is also possible, though we recommend this only for those who enjoy experi-
menting, as traits tend to compartmentalize themselves in individual offspring. Seedlings tend to be
very heterogeneous and can be harvested in the second year at the earliest, but it is better to wait until
the third year.
HARVEST
Harvest seeds as soon as they turn brownish. Dry seeds on the seedhead, thresh or pluck off
seeds, winnow with a sieve and in the wind.
SELECTION CHARACTERISTICS
Individual varieties are distinguished by the inner (some are blood-
red) and outer color of their leaf stalks, the thickness and length of leaf stalks, and earliness. Other se-
lection criteria:
• late flowering
• speed of secondary growth
DISEASES AND PESTS
Diseases are rarely a problem with rhubarb, though plants can be affected by
some viruses and downy mildew (
Peronospora jaapiana
). Turnip mosaic virus can also affect rhubarb
and is a concern for commercial rhubarb producers. Symptoms: lightly colored mosaic or bulges on
young leaves, eventually leading to intense yellow discoloration. Treatment: remove affected plants
(viruses cannot be cured). Downy mildew does not cause major problems. Dock rusts (
Puccinia
phragmitis
) may appear occasionally in gardens sited near reeds. Symptoms: round, red-outlined leaf
spots, white patches of spores on leaf undersides.
A frog's-eye view of a rhubarb plant (late spring)
