Why do my zucchini keep shriveling up?

Zucchini Blossom End Rot

Q: I’m growing zucchini in large pots on my deck. The plants look great but some of the young fruit look like they set, but soon start to shrivel from the blossom end and never mature. What’s going on?

A: Three possibilities come to mind. Inadequate pollination. Too dry between waterings. Blossom end rot. If you do not see bees on your flowers you may need to use a small paint brush or Q-tip to pollinate the female flowers, using pollen gathered from the male flowers. Check your watering practices. Squash require a lot of water. If they dry out every day, consider moving them into larger pots. Finally, blossom end rot can affect squash and other fruiting vegetables. Make sure you are using a fertilizer containing calcium. Lack of calcium, combined with erratic watering leads to blossom end rot which is simply a cultural problem. Not a disease.

Read our Q & As with Keith Funk answering common Colorado gardening questions here. You can also hear him on the Garden Wise Radio Show