Question: I like to catch rain water in a tub to water my houseplants with but of course after only a couple of days I have a whole lot mosquito larvae. Is there anything I can add to the water to keep the mosquitoes from laying their eggs?
Answer: First, you could plant some things that are reportedly mosquito repellent around the area. Some choices are: Citronella plants, citronella grass, 'Citrosa' geraniums and thymus citriodora. They are available from Richter's Herbs at www.richters.com ph. 905-640-6677.
However, I think your best bet would be to try "mosquito biscuits". They are little donut shape rings that you float in rain barrels, ponds, birdbaths, etc. that are imbedded with a bacterium (Bt 'Israelensis) that kills mosquito larvae. They last about 30 days. They don't stop the mosquitos from laying eggs, but they stop the eggs from hatching. You can usually pick them up at garden centers that sell pond supplies, or from Gardener's Supply Co. at ph. 800-863-1700.
Perhaps if you tried some of the plantings as well, you could have a multi-pronged defense!
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