Pollination
Some greenhouse plants, such as tomatoes, need to be pollinated before they can set fruit. Greenhouse fans, which circulate air and keep foliage dry, don't generally create enough wind for pollination. Manually tapping flowers to release pollen grains is a problem if you can't fit it into your schedule. You can use battery-operated pollinating tools to speed up this task, but they still require an operator. Some bumblebees are specifically bred as greenhouse pollinators. Costs for using these bees include the box or hive of bees and prepackaged nectar as a supplemental food source for them. Pesticides that control other insects and diseases may kill bees, so consider this when deciding how to control pests.