Cross-pollination can be prevented by maintaining a minimum of 14 days' difference in maturity dates. For example, Saturn is a super-sweet cultivar with 75 days to maturity. It could be planted at the same time as Silver Queen, which is a standard cultivar that matures in 95 days. If the cultivars you wish to plant have the same days to maturity, simply plant one and then delay planting the other for two weeks.
Alternatively, plants may be isolated from each other. A separation distance of 700 feet will provide complete isolation of white, yellow, and high sugar varieties. A distance of 250 feet will result in some cross-pollination, but not enough to appreciably affect quality.
