_Irrigation._--In Riverside grapes cannot be grown without irrigation on the mesa lands, with the exception of one or two localities in the arroyo. In the Ontario district, raisin grapes may be grown without irrigation in the center of the valley, but on the mesas, higher on the sides, they must be irrigated, and even in localities where they could be grown without artificial irrigation the same is always practiced whenever it can be obtained. Less water is, however, needed than in the San Joaquin valley, but more than would suffice in El Cajon. Through the nature of the gravelly subsoil, the raisin land cannot fill up with water. Seepage is only possible to a limited degree; summer irrigation is always required. The vines are irrigated three times a year, in April, June and August. The system of furrows is used, and a ten-inch flow is considered enough to irrigate one acre of grapes during one day and night each time. In Ontario the raisin grapes are irrigated every five weeks, not, however, while they are in bloom, as it is considered best to wait until the berries are well set. In Redlands, one irrigation after the winter rain ceases is considered enough, even on soil with thirty feet to water. _Soils._--The soil in San Bernardino county varies considerably. In Riverside and Redlands the best soil is a reddish loam, with some sand and gravel. But in Riverside we also find sandy soil of lighter color and strength, which, however, is less suited to grapes. In Ontario the soil varies from a heavy clayey _adobe_ to a lighter but very rich sandy loam of a grayish color. The very sandy soil in some river bottoms, especially around Lugonia, has, through experience, been found to be entirely unsuited to the raisin grapes.