Strawberries, the most popular fruit crop among home gardeners, are easy to grow in all parts of the United States and southern Canada. The plants grow 6 to 8 inches tall in a thick central crown from which emerge dark green three- leaflet leaves and fruit-producing stems; each plant will spread about 12 inches across, but runners may extend several feet beyond.

Black raspberries, often called blackcaps, and purple raspberries, which are hybrids between red and black varieties, have quite a different flavor from that of red raspberries. Yellow raspberries are mutations of red varieties and are like them except for color.

There are two categories of red and yellow raspberries, the more important being the common raspberry, which ripens in early to midsummer. The other type is called fall or everbearing; although lacking the subtle flavor of the summer varieties, it produces both an early-summer crop on the previous season’s growth and a fall crop on the current season’s growth. Excellent varieties of summer-fruiting red raspberries are Canby, Hilton, Latham, Taylor and Willamette; of these, Canby and Willamette grow in Zones 5-8, while the others grow in Zones 4-8. Recommended varieties of everbearing red raspberries include Heritage, Falired, Durham, Indian Summer and September; all grow in Zones 4-7. Two summer-fruiting yellow raspberries are Amber and Golden West; an everbearing yellow raspberry is Fall Gold. Among the recommended varieties of black raspberries, all of which grow in Zones 5-8, are Allen, Black Hawk, Bristol, Cumberland and Dundee. Outstanding purple raspberries are Clyde and Sodus.

Feed raspberry plants in early spring by scattering 10-10-10 fertilizer around them at the rate of 1 pound per 10 feet of row. Birds are very fond of raspberries, but the fruit can be protected with plastic netting. Raspberries are ready for harvest when the berries separate easily from the stems. To pick them, gently pull each ripe berry between the thumb and forefinger; it will drop into your cupped hand. Handle the berries carefully and do not pile them into a deep container, for they crush easily. Do not wash or wet them because the water dilutes their flavor. Red and yellow raspberry plants propagate themselves, spreading by underground suckers.

Raspberries should never be planted where eggplants, peppers, potatoes or tomatoes have grown within three years, because they are susceptible to soil- borne diseases associated with such plants. Spring planting is recommended. If plants are to be grown in rows, set red and yellow varieties about 2 to 21/2 feet apart in rows about 7 to 8 feet apart; set black and purple varieties 3 feet apart in rows 8 feet apart.

To get new black and purple raspberry plants, use the method called tip layering: cover the tips of the arching stems in the late summer with a shovelful of soil-a new plant will start to root at that spot in the spring. Cut off the tip, dig up the rooted plant (which may or may not yet show growth aboveground) and replant it elsewhere.