…We gardeners always hear that rainwater is the best for our plants. Orchid growers especially will go to great lengths to acquire and save it. I spoke with Walt Nelson, horticulture program leader at Monroe County’s Cornell Cooperative Extension, to find out why.
Water in our area tends to be “hard,” which means that it contains a lot of dissolved calcium. The calcium comes from Lake Ontario, the Genesee River and the limestone (calcium carbonate) that forms the bedrock in much of our area.
Hard water isn’t bad for most plants (except orchids and carnivores) ” in fact calcium is a necessary plant nutrient.
Actually the article is incorrect. Even if you are not in an area that has hard water the high chlorine concentration in your tap water is bad for plants. Plants prefer slightly acidic water.
If you can collect rainwater for your house plants they will love you for it. Stick any old container outside to collect the water near a spot where it runs off the roof or down a drain spout.
If you are not in a place where you are able to collect rainwater add a tablespoon of vinegar to a gallon of tap water to adjust the acidity for your plants.