As a substitute for in-person programming, we’re offering a series of posts on starting a vegetable garden. This science-based information comes from the Seed to Supper program, developed by the Oregon Food Bank.
Along Oregon's North Coast, early spring is a good time to plant potatoes and parsnips. Parsnips are best planted from seed; for potatoes, use seed potatoes purchased from farm or gardening stores. Potatoes make good companion plantings for beans, corn, marigolds, horseradish, and members of the brassica (cabbage) family.
"Suitable companions provide benefits such as nitrogen fixation, production of invigorating exudates, repelling or trapping of insect and other pests, and weed suppression, among other benefits," says Leonard Githinji, Ph.D., Assistant Professor and Extension Specialist, Sustainable and Urban Agriculture, Virginia State University.
Like carrots, parsnips are short plants. They have a 3" x 3" footprint and can handle some shade. They're best planted in April and May and will be ready for harvest 110 - 120 days later. Parsnips are good succession plantings - plant more every week or two to spread out the harvest. Tender when small or medium-sized, parsnips become woody if they grow too large. Parsnips are sweetest after exposure to 40 degrees F or below.
To harvest parsnips, loosen soil, grasp at base of leaves, and gently pull. To store, dust off, cut tops, and store for two to six months in a plastic bag in the fridge.
Potatoes are medium-high plants that comes in many varieties. Mature plants need a 12" x 12" footprint. Some shade is okay. Potatoes can be planted through June. They're generally planted in hills (groups), not rows. To prevent disease, cut seed potatoes, one or two "eyes" to a piece, then leave out overnight before planting eye-side up.
As potato plants grow, you can hill up dirt around the stem and leaves closest to the soil to encourage more growth. When plants flower, you can harvest new potatoes by loosening the soil around a plant with a digging fork. For full-sized potatoes, wait until above-ground parts of the plant die back and harvest the entire bed. Green potatoes have been exposed to too much sun and could cause digestive problems
To store potatoes, wipe off dirt, cure in a cool place for 10 days, then store for six to eight months in a cool, dark place. Don't store in the refrigerator; at temperatures that cold, potatoes lose flavor.
To cook parsnips, try this Food Hero recipe for roasted parsnips and carrots. Potatoes can be roasted, too, following similar directions; because they're softer, they'll take less time.