Confessions of a Houseplant Killer 3

Welcome to the 3rd installment of Confessions of a Houseplant Killer.

Because we have such low light in our house, this was a plant I actually bought, as it had descriptors like “thrives on cruel neglect” and “hard to kill.” Oh, really?

Here we go again!

Zamioculcas zamiifolia, also known as the “eternity plant” or “ZZ,” the ZZ plant is an upright-growing tropical plant that can grow in practically any environment. Other than a pot with adequate drainage and a location away from cold drafts, the ZZ plant doesn’t need much and grows well in low-lit areas. So, where did I go wrong?

Shameless stock photo of a healthy plant, not mine!

As I’ve written in my prior confessions, the rule of thumb with most houseplants is to always err on the side of under watering. That’s especially true for this drought-tolerant plant that stores water in its rhizomes. Generally I would deeply water every few weeks when it felt dry. It was doing great until one day when one of the leaves started turning yellow.

After some investigation and a water test from the Walton County UGA extension office, I realized it was because there was too much sodium in the water! We recently installed a water softener, and even though I was using reverse osmosis filtered drinking water, it still contained too much sodium!

Here’s a copy of my drinking water report from Walton County UGA Extension.

Though it says it’s acceptable for drinking, even a small amount of sodium is enough to affect a plant’s health. Upon further investigation I found out that the sodium in softened water interferes with the water balance in the plants by making them believe they’ve taken in more water than they actually have, thus causing the plants to die of thirst. Not only does the salt in softened water hurt the plants you water with it, but the salt will build up in your soil and make it difficult for future plants to grow.

Also, synthetic fertilizers contain soluble salts such as sodium, chloride, boron, and magnesium which can also accumulate in soil over time. If you see signs of sodium buildup such as a white powdery crust on top of the soil, white stains on your pots, or yellowing and burned leaf tips, you’ll need to correct the salt levels in the soil through a process called leaching. 

Before you start, scoop out any layer of salt that is visible, no more than an inch from the top. Next, frequently water the plant enough to drain out completely. Do this at least three times with the same amount of water as the pot’s volume. For example, if you have a one-gallon pot, water one gallon at a time. Be sure to toss out any water that’s left in the drip plate as it can be reabsorbed back into the soil.

Note that leaching will not only draw the salt out, it will also draw out essential nutrients and minerals, so you’ll need to add them back with fertilizer. Click here for tips on how and when to fertilize and here to learn more about leaching.

You can prevent salt build-up by choosing mineral-free water such as collected rainwater which has no added chemicals. I now use non-softened, uv-filtered water from our well for all my indoor and outdoor plants.

If you would like your water tested, email Walton County Extension at uge1297@uga.edu or drop by the office located at 1258 Criswell Road, Monroe, GA to pick up sample bottles and instructions. Click here more about the different water tests available.

Share your near-death/killer houseplant confessions by filling out the form on our website www.waltonmastergardeners.com/ask-mg, and we'll help you investigate!