If you microwave water for 1 minute and water plants with it, will it grow better or worse than a plant watered with warm tap water?
Water and Its Effects on Plant Growth
Certified GKH Gardening Expert
Generally, most plants prefer water that is at least room temperature. The problem with overly hot water, like that from being boiled or microwaved, is that it could potentially scald the plant and burn its roots. Also, just as with overly cold water, it can cause the plant to go into shock. That being said, a little hot water bath now and then to alleviate pest issues is okay, so long as the temp doesn't climb above 120 F. and only for a short period.