www.towergarden.com/blog.read.htm..._no_fruit.html
You should probably hand pollinate if:
- You don’t see bees or other insects hovering around your flowering plants
- You’re growing indoors, in a greenhouse or on a screened-in porch
- Your plants produce fruit that shrivels and dies before maturing
Even with healthy pollinator activity, you may consider hand pollinating simply to prevent cross-pollination between similar plants. This is important if you want to save seeds from your garden to grow more of the same plant—a common practice for heirloom varieties.