Instructions for growing vegetables usually include the phrase "full sun," but there are many vegetables that grow in part shade as well. Vegetables that grow in partial shade need the same considerations for water, compost, and organic insect controls as the rest of the vegetable garden. Partial-shade gardens include garden areas shaded by taller plants as well as those where structures block the sun for part of the day.
According to Colorado State University Master Gardener John Durham, leafy vegetables are the most tolerant of shade. Salad greens such as arugula, Swiss chard, spinach, lettuce of all varieties, and radicchio grow well in part shade. These plants also have the advantage of being useful at any stage of maturity. The seedlings can be thinned and used in salads from the time they are 2 to 3 inches in height. As lettuce, spinach or chard continues to grow, individual leaves can be harvested and used. Salad greens in the shade give a continuous harvest when they are planted successively throughout the growing season. Plant leafy vegetables where they can take advantage of afternoon shade cast by big-leafed plants such as zucchini and taller plants like beans and corn.
Half a day of sun is needed to grow root vegetables. Micro-climates in the garden that are created by trees can provide a good growing area. Potatoes, beets, carrots and turnips are root vegetables that tolerate half a day of shade. Some heritage varieties of beets, such as 'Chioggia,' with its red and white striped bulb, add interest to a shady vegetable garden. Potatoes can be grown in a stack of straw mulch or in a plastic garbage can in partial shade. Popular varieties include 'Red Norland', 'Norgold Russet' and 'White Rose'. Turnips are shade-tolerant and mature in two months. They can be planted in either spring or fall.
Mustard, Collards and Rhubarb
Collards are an easy-to-grow, nutritious leafy vegetable that produces abundantly and is tolerant of many conditions. The leaves can be picked as the plant grows or left to harvest all at one time. Collards grow well in full sun but will tolerate light shade. The Japanese mustard green 'Mizuna' has a mildly peppery taste and is harvested in only 40 days. At 20 days the individual leaves can be plucked for salads. It is a cool season mustard plant that will tolerate very mild shade. Make successive plantings in spring and fall for continuous supply of this hearty salad green. Rhubarb is an old fashioned garden plant that grows well with a half day of sun. Too much heat wilts the big leaves. Rhubarb is harvested from late spring through mid-summer.