Some of our house plants thrive in soil with a low pH and with low levels of lime, or no lime at all, in the soil. These plants are also pretty sensitive to being watered with water containing lime.
Here are a few signs that your plant is suffering from too much lime, and what you can do about it.
SIGNS THAT THE WATER CONTAINS TOO MUCH LIME
Dry or brown leaf tips
Leaves fall off
Flowers turn brown and might fall off
WHAT YOU CAN DO TO SAVE YOUR PLANT
The absolute best way to save an acid-loving (or just Lime-hating plant) is to water them with rainwater. Rainwater hardly contains any levels of lime at all and is, therefore, the best option for your lime-hating friends.
So start collecting some rainwater in a clean bucket/vase/container and you're good to go for some time.
You can buy and use distilled water for your lime-hating plants, but you can of course also make this yourself, even if it might be a bit tricky. To do so:
Collect the water vapor in a clean container (this is now lime-free)
Let the lime-free water cool down
Water your plants with your own lime-free water
Filtered water / water from a water purifier is often lime free and therefore safe to use on your lime sensitive plants. Just make sure that your purifier is able to remove lime and you're good to go!
MYTHS & DON'TS
There are several different "tips" regarding lime-free water and how you can do this at home in an easy way, but did you know that some of them are actually faulty and might even be harmful to your plants? Here are some of them:
"The water from the dryer is lime-free" - This is correct, however, the water from the dryer also contains residues from your clothes, detergents and fabric softeners which sometimes can be harmful to a stress-prone plant, so if you have the possibility to water your plant with another type of lime-free water that would be amazing!
"If you pour water into your watering can and then let it sit for some time the lime will evaporate / sink to the bottom" - This is sadly incorrect (if only it was this easy). We therefore suggest using rainwater and / or distilled water instead.
"You can use softened water to water your lime sensitive plants" - Softened water often contains high levels of sodium (attained from salt) which might harm your plants since most plants can't tolerate high amounts of salt. This will also interfere with the water balance in the plant, which might kill it by "fooling" it into thinking that it doesn't need any more water, causing it to die of thirst.
FOR THE PLANT NERD
MORE INFORMATION ABOUT LIME
Hard water often contains high levels of lime / chalk. This can cause limescale deposits to develop - this is the same stuff as you might see building up in your home, around taps and sinks etc.
Is limescale harmful to my plants? Limescale buildup is unsightly, and can also potentially cause damage to your houseplants. This is because it can interfere with nutrient availability. If you see limescale on your plants, on the soil or on the pot, you can remove it by scraping or wiping it off. Usually a wet cloth is enough to remove the buildup - just make sure to use distilled water or rainwater when cleaning, otherwise you’ll just be adding to the problem!
Examples of plants that don't like lime:
Rhododendrons (several different types)
Azaleas (Rhododendron simsii, Rhododendron indicum etc.)
Blueberries (Vaccinium corymbosum, Vaccinium myrtillus etc.)
Camellias (Camellia japonica, Camellia sinensis etc.)
Heather (Calluna vulgaris)
Bleeding heart (Lamprocapnos spectabilis)