Hi Jeff, I suggest trying a product called mosquito torpedo in rain barrels. I also use this great product in my water garden and the mosquitoes never reach adulthood. The good thing about this product is that you just pop one in the water and it starts to work immediately. It will also not harm humans, animals, fish and most importantly…vegetation!

The way Mosquito Torpedo works is that it slowly releases an insect growth regulator into the water that prevents adult mosquito development for two months or more (per torpedo). Below is list of places where you can use a Pre-Strike® Mosquito Torpedo®:

• Bird baths
• Water Gardens
• Roof Gutters
• Old Tires
• Pool Covers
• Ornamental Foundations
• Flowerpots or planters
• Urns
• Unused swimming pools and spas
• Tree holes
• Rain barrels
• Garbage cans
• Wheelbarrows
• Privately owned ponds
• Flooded areas
• Animal watering troughs
• Man made depressions
• Standing water anywhere!

Toss one in and your mosquito problem is solved, you could also purchase a fully enclosed rain barrel (like the ones I make) and have no need to kill mosquitoes. Hope this helps, -Aaron