Answer: Rainwater is the water of choice because it is free of chemicals such as chlorine and fluoride, normally present in city water. However, this is more of an issue with houseplants than plants outdoors in the garden. Containerized plants don't have the benefit of far-reaching root systems, or the filtering action of soil. Plants outdoors benefit from the several inches of soil that are above the root systems. The soil particles tend to filter the water so what reaches the roots is generally purer than the tap water you use. So, since you have no rainwater to use on your plants, plain water from the hose should be just fine.
Best wishes with your garden!
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