Common Name: Jicama, Yam Bean
Pachyrrhizus erosus (pah-key- RISE-us eh-RO- sus)
Habit: Vigorous spreading, bushy annual vine that has heart-shaped leaves and blue or white flowers and lima bean-like pods on fully developed plants. Height: 3-4 feet, width: 4-5 feet, recommended spacing : 4-8 feet. Jicama is a root vegetable. Member of the morning glory family, it's related to sweet potato. Above ground, the plant grows as a broad-leafed vine about 20 to 30 feet long depending on variety. It blossoms with light purple or white flowers, which will produce fuzzy beans. The flowers are often removed so that the tubers will be larger. Tuber is shaped a bit like a turnip or a beet and can weigh from 8 oz to 6 pounds or more. The tuber has short roots attached to it.
Culture: Easy to grow in well-drained healthy soils. Plant the beans in the spring. Rows 2’-3’ apart with plants 8”-10” on center. Use the basic fertilization schedule and remove flowers from young plants to encourage the expansion of roots, the edible part of the plant. Jicama is grown from square, brownish seeds that take 5 to 9 months for its roots (tubers) to be ready to harvest.
Harvest: Like potatoes, jicama may be harvested at any time during root development although miniature roots have tender skin. As with potatoes, jicama can be harvested anytime although tubers will be small if harvested too early. If not harvested early enough, the tubers can grow 6 feet long and weigh about 50 pounds but at this point they are very woody and past their usefulness for food. Choose smaller ones with no blemishes on the skin as blemishes indicate bruises underneath (though color blotches are fine.) Larger ones can be a bit woody, dry and starchy.
Problems: The usual caterpillars and beetles attack the foliage at times but it’s rare and usually little problem. Only the root portion of jicama is edible. The leaves, flowers and vines of the plant contain rotenone, a natural insecticide designed to protect the plant from predators. Eating any of these parts of the plant can cause a toxic reaction. While the seedpods can sometimes be eaten when young, the mature pods are toxic.
Varieties: (Pachyrrizus erosus) has two subtypes: one with watery, transparent juice (agua) and one with a cloudy, milky juice (leche.) The leche type has a longer tuber, the agua type is more onion shaped.
Notes: Native to Mexico and northern Central America. Common name is pronounced HICK-a- ma. Only the root portion of jicama is edible. Leaves, flowers and stems of the plant contain rotenone, a natural insecticide that I don’t even recommend for pest control. Eating any of these parts of the plant can cause a toxic reaction.
COOKING TIPS FOR JICAMA
Peel before using.
Jicama can be prepared any way in which potatoes can, but can also be eaten raw or boiled. Raw Jicama tastes a bit like water chestnuts. It can be diced or cut into strips as a crudité for dips, added to salads or used in stir-fries. It will retain its crispness if cooked lightly.
Unlike many other vegetables, such as potatoes or avocados, Jicama won't go brown right away when exposed to air. If you're going to leave the cut pieces exposed to air for a long time, however, it is not a bad idea to brush them with lemon or limejuice.
Some of Bob Webster’s jicama production. Join the Organic Club of America and get some of his seed as a bonus.