CORVALLIS, Ore. – Bring a taste of South America, Europe or Asia to your garden this year by adding a diverse array of exotic vegetables.
A varied collection of plants can also reduce the potential for pests and diseases in a garden, said Jim Myers, a vegetable breeder with the Oregon State University Extension Service.
"There's a lot of natural, biological control that goes on in a garden that we're not even aware of when we have biodiversity," Myers said.
When shopping for exotic plants, buy only seeds or starts from Pacific Northwest-based nurseries and suppliers, Myers advised. If you order online or while traveling, globetrotting plants can carry hitchhiking pests or diseases.
The following plants were tested at OSU fields and perform well with varying degrees of success in a Pacific Northwest climate, Myers said.
- Yacón: Smallanthus sonchifolius. The yacón is an Andean relative of the sunflower that grows 6-8 feet tall. It's tasty in a salad or as a snack but doesn't contain enough carbohydrates to become a diet staple, according to Myers. The perennial performs well in both eastern and western Oregon. While similar to the Jerusalem artichoke, yacón's tuberous roots grow to about the size of a sweet potato. Plant seed pieces in the spring for an October harvest. Yacón can overwinter in the ground where the soil does not freeze.
- Mashua: Tropaeolum tuberosum. Mashua is grown in the Andes for its edible tuberous roots. A relative of the nasturtium, mashua's showy red flowers emerge in late September. A vigorous perennial, it can climb 7-13 feet high. Mashua has a pungent flavor, similar to a radish. This hardy plant thrives even in poor soil. Cultivate it similar to how you would a potato; plant in spring for a fall harvest.
- Oca: Oxalis tuberosa. Oregon does not offer an optimum climate for oca, but it can be grown in select areas in the western part of the state. Tubers will grow small without tropical heat. It can't survive frost but tubers will overwinter in the ground as long as they do not freeze. Plant in spring for November harvest. Cultivate as you would a potato. The tuber is edible and the leaves and young shoots can be eaten as well. Its flavor is slightly tangy, caused by its oxalic acid content, which should not be consumed in large quantities. Some varieties have been bred for lower oxalic acid content.
- Cardoon: Cynara cardunculus. The cardoon is related to the artichoke. Both are perennial members of the thistle family and hail from southern Europe. It needs full sun. Good for the Willamette Valley and eastern Oregon. Its leaf stalks produce in a flush of springtime growth; in the summer there is little growth. Harvest the leaf stalks similar to the way you would celery. Stalks need to be cleaned and peeled before cooking. Plant transplants in spring.
- Asian greens: Any green in the Brassica rapa family. A good one to try is pakchoi cabbage, which has large white, fleshy stems. When eaten, it has a soft, creamy texture. "It has a little bite to it but it's pretty mild," Myers said. This cool-season crop goes well in salads or cooked. Plant it in early spring for an early summer harvest. Not tolerant of winter conditions. At OSU, pakchoi cabbage is planted in July for a fall harvest.