Why Cucumbers Stay Yellow: Poor Pollination

Cucumbers that turn yellow before reaching full size usually suffer from incomplete pollination. Fruit expansion is driven by hormones from developing seeds; without pollination, seeds don't form, hormones are lacking, and fruit aborts or ripens prematurely.

Fix: Plant pollinator-friendly flowers (cosmos, zinnias, sunflowers) near cucumbers at planting time. Avoid insecticides during bloom. Hand-pollinate with a small brush if bees are scarce.