Serr is the preferred walnut variety for marginal soils and hot climates. Unlike other cultivars, Serr seems to prefer shallower, heavier, less fertile soil and is highly resistant to sunburn. With an early to mid-season harvest, Serr is large in size with a fair-to-good shell seal. Serr kernel crackout is 59% with an average kernel size over 7 grams. The fast-growing Serr tree requires a spacing of at least 40 feet due to moderate spreading and good-to-excessive vigor. Suitable pollenizers for Serr include Chico and Tehama.