2 Staples You Already Have In Your Home Will Help Peace Lilies Thrive

Peace lilies (Spathiphyllum spp.) have long been houseplant favorites, with their low-maintenance needs, vibrant foliage, and graceful white blooms. They're not picky about their lighting and won't hold your busy schedules (and neglect) against you. We also benefit from having peace lilies in our home. They are known to help purify the air we breathe by potentially removing toxins like formaldehyde. 

As with any houseplant — even easy-to-care-for varieties like the peace lily — it's essential for plant parents to give it the right nutrients and to keep an eye out for signs of deficiencies. Thankfully, giving your peace lily some TLC can be easy, with two items that are commonly found in your home: coffee grounds and Epsom salt. If your peace lily is content, adding coffee grounds provides an extra boost of nitrogen for leaf growth and improves soil health. For a peace lily showing signs of magnesium deficiency, like discolored foliage, brown tips, and wilted leaves, spraying its leaves with a mixture of Epsom spray and water can restore its nutritional balance. 

Coffee grounds are known to contain nitrogen, as well as phosphorous and potassium — key plant fertilizer ingredients — which means sharing a cup of Joe with your peace lily is like giving it a healthy treat. But just like the customer with a highly customized coffee order, the peace lily also has its preferences. One of the most important details to remember when using coffee grounds as a fertilizer is to avoid fresh grounds, which have high levels of acid and caffeine that can harm your plant. Used grounds have a pH range of 6.5 to 6.8, making them more neutral and, thus, safer for your plant — a decaf version, so to speak.

One of the most effective ways to use coffee grounds as food for your peace lily is to make a liquid fertilizer that does double duty by also watering your plant. Mix 1 cup of coffee with 5 gallons of water and let it steep for several days before straining the grounds and using the liquid to water your plants. You can also combine coffee grounds with compost and add this mixture to your potting soil. However, make sure that only around 10% of your mixture is made up of the coffee grounds.

A third option is to sprinkle — not layer — dry coffee grounds on the soil. If you use too much, you risk creating a compact layer of grounds that hinders airflow and drainage through the pot. Regardless of which option, apply the fertilizer one to two times in the spring or summer when the peace lily is actively growing. 

Just as Epsom salt is used to treat ailments or relieve stress in people, this mineral salt can do the same for peace lilies. Epsom salt is a compound of sulfur and magnesium, the latter of which strengthens plant cells, improves the lily's ability to absorb nutrients, and boosts chlorophyll levels — all of which are vital to a plant's well-being. While fertilizing with coffee grounds can be done on a regular basis, even on healthy plants, Epsom salt is only necessary when you see signs of magnesium deficiency. 

Symptoms include yellowing between veins on foliage, curling leaves, or stunted growth, but since these signs also can be indicative of other problems, always test the soil before applying Epsom salt, as a plant also can suffer from having too much magnesium. A plant might be low in magnesium when its soil is too acidic or course and cannot retain the amount of magnesium that your peace lily needs. And just like how minerals react to each other in human bodies, the same goes for plants. If the soil contains too much potassium, ammonium, or calcium, your plant might struggle to take in magnesium. 

Watering your peace lily with Epsom salt is quite simple, especially because it easily dissolves in water. Instead of applying Epsom salt directly to soil either as granules or as a liquid, spraying the plant's leaves is the most effective option. To do so, mix 2 tablespoons of Epsom salt in a gallon of water and spray the peace lily's leaves once a month to maintain your plant's magnesium levels.