How far apart should cucumbers and squash be to avoid cross-pollination?
Cucumbers (Cucumis) and squash (Cucurbita) are not related closely enough to cross-pollinate, so they may be planted next to each other with no danger of cross-pollination. If they could cross-pollinate, it would still be all right, because the fruits wouldn't be affected. This is because the fruits are part of the mother plant; cross-pollination affects only seeds. So unless you're saving the seeds to plant next year, don't worry about squash crossing with squash (or pumpkins or any other type of vegetable).