Mosquitos are terrible right now, mostly because they have had lots of water to breed in lately. Swarms of the biting bugs can make gardening chores miserable.
Mosquito control advice always includes emptying any containers that contain open water
If you have potted plants in trays with water, add gravel or sand around the pot. Use enough to cover all open water in the tray.
For ditches, flooded yard areas, anything that really must have standing water in it, a little bit of oil will form a floating surface slick that suffocates mosquito larvae.
Add one-quarter teaspoon of oil (vegetable oil, horticultural oil, Neem, common mineral oil) per gallon of water, or use 1 tablespoon per 100 square feet. Replenish every few days as the oil slick disappears.