Spearmint grows well in nearly all temperate climates. Gardeners often grow it in pots or planters due to its invasive, spreading rhizomes. Spearmint leaves can be used fresh, dried, or frozen. They can also be preserved in salt, sugar, sugar syrup, alcohol, or oil. The leaves lose their aromatic appeal after the plant flowers. It can be dried by cutting just before, or right (at peak) as the flowers open, about one-half to three-quarters the way down the stalk (leaving smaller shoots room to grow). Some dispute exists as to what drying method works best; some prefer different materials (such as plastic or cloth) and different lighting conditions (such as darkness or sunlight). Spearmint essential oil has had success as a larvicide against mosquitoes. Using spearmint as a larvicide would be a greener alternative to synthetic insecticides due to their toxicity and negative effect to the environment. Conditions (such as darkness or sunlight).