Submitted to the Contra Costa Times on April 6, 2006

Q. How can I grow Rhubarb?

A. Rheum rhabarbarum L.  Rhubarb is sometimes known as the Pie plant.This cool-season perennial is a member of the buckwheat family. Originally from central Asia, Rhubarb has a long ethnobotanical history with records on cultivation going back over 2000 years.  Rhubarb was introduced to Britain in the 16^th century and was brought to North America in the 18^th..  The large thick stalks  are eaten, most frequently in deserts. The stalks  are low in calories and contains vitamins A and C, thiamin, riboflavin, niacin, potassium, phosphorous, and are an excellent source of dietary fibre, with a unique tart flavor. For rhubarb to produce well, it will require winter temperatures below 40F  so that it can become dormant, and summer temperatures at about 75F. If it becomes much warmer, the plants will go summer dormant and will not thrive.  Planting can last for up to 8 years, although insect and disease problems can reduce that amount of time.

Rhubarb is most often purchased as crowns consisting of woody rhizomes, roots and buds. It is not usually propagated from seed because of the variation that occurs in color and stalk size.  If you purchase dormant crowns, soak them for a short time in tepid water, and plant in a well prepared bed. The bed should have been double-dug to a depth of 18” ( 46cm). with about 50% of the soil’s volume replaced with aged compost. Rhubarb does best in slightly acidic soils, with slightly acidic water. Neither of these are common in this area. Test your soil pH (you want it to be about 6- 6.8 pH) If your irrigation water has a pH higher than 7 you may need to take that into consideration also. Plant the crowns about 4” below the surface, spaced about 3’ apart. The area will need to be kept moist, weeded and in full sun.

Rhubarb forms large plants that need to left alone for the first year. Stalks can be harvested the second year as they mature, being careful to leave enough to supply energy for the crowns for the next years crop. There are red and green and speckled types of stalks available.

In the Bay Area there are few insect pests. Rhubarb is susceptible to root rots, and requires good drainage.  Be careful with Rhubarb. The leaves contain oxalates and are poisonous. Only the stalks are eaten.

For more information see publication # 8020 at http://anrcatalog.ucdavis.edu