Rhubarb is a cool season crop recognized by its large green leaves and red stalks. The leaves are not a vegetable and should not be used for food, as they are poisonous. Before using rhubarb in recipes, remove all leaf tissue and use only the stalks. The stalks are similar to celery with a strong sour or tart flavor.
Although rhubarb is a vegetable, it is classified as a fruit due to its use in pies, jams and jellies, and liquers.
References: Ohio State University Extension, Old Farmer’s Almanac, USDA.
TYPES, VARIETIES & CUTS
Rhubarb is generally available in three types: red, speckled (pink), or green. Of the red type, there are several Crimson varieties including Crimson Cherry, Crimson Red, and Crimson Wine. These varieties produce stalks of bright red. In addition to the Crimsons, there are also Valentine, Canada Red, and Cherry Red. Cherry Red is distinguished by its deep red color and long, thick stalks. Most red varieties are more tender than others.
Speckled or pink varieties include Victoria which produces large, long, round stalks. The pink speckling is more pronounced at the bottom of the stalk while the tops are light green. Similar to Victoria, German Wine is more vigorous with darker pink speckling.
Riverside Giant is a green variety that produces long, large, green stalks.
References: Old Farmer’s Almanac, Oregon State University, University of California, Virginia Cooperative Extension.
PESTS & DISEASE
Crown rot is noticed in the lower leaves when they turn yellow, then brown, and wilt. Damaged petiole bases are brown with a mushy texture. Root rot is the result of poor drainage or over-watering. Highly rich organic soil will help with prevention.
Ramularia leaf spot first appears as tiny red dots on the leaves. These dots continue to grow up to a half-inch or more in diameter and change color from red to tan. As with both crown and root rot, well-drained, fertile soil can help prevent the disease. Infected leaves should be removed promptly and plant debris should be completely destroyed after the first frost.
Japanese beetles feed on leaves leaving little behind but veins. These pests are extremely destructive as adults and larvae. Adult beetles are metallic green in color with brown wings. Larvae (grubs) feed on the roots.
Potato flea beetles eat holes in leaves and much like a flea, can jump if disturbed while feeding. Army worms feed primarily on leaves. For approximately two and a half weeks, larvae feed on the plants before moving to the soil to pupate. After two weeks, the moths emerge.
References: Iowa State University, Purdue University, Old Farmer’s Almanac, UC Davis Postharvest Technology website, University of Minnesota.