Why Do the Leaves on My Peace Lily Get Brown?

Brown leaves mar the beauty of your peace lilies.

Peace lilies require little in the way of special care. They resist disease and pests quite well if you keep them healthy. Browning leaves are one of the first signs of a variety of problems that can make your plant sick. Light, water and fertilizer can all be factors, but sometimes peace lilies can react to being messed with. They don't like change much.

Change

If you have moved the plant or changed the way you water, if the plant is new or recently repotted or it has recently put on new leaves or blossoms, peace lilies can develop brown tips. Change can be as much of a factor in browning as more direct factors. Instead of repotting, fertilizing or adding water, you may need to do the opposite -- leave it undisturbed, dry it out or rinse it.

Natural Causes

Many varieties of peace lily are bred to produce lots of flowers. Producing flowers pulls nutrients away from leaves and roots. A heavy flower load can pull water and nutrients from the plant itself and starve older leaves causing yellowing and browning. If you have new green leaves still growing, the browning may be natural. Trimming the old leaves can perk up the whole plant.

Fertilization

Over-fertilization is one of the more likely causes of leaf browning. You should not fertilize peace lilies more than once every two or three months. If you suspect over-fertilization, rinse the plant with clear water. Be sure drain holes are open and that water runs through freely. Another solution is to repot the lily in fresh, unfertilized soil. If a plant has been in the same pot too long, salts leach from fertilizer or alkaline tap water and build up in the soil. It will take weeks for the plant to rebound. Don't fertilize for at least two months.

Watering

Peace lily leaves can brown and wilt if you water too much or too little. Don't let the plant wilt between waterings. Water at the first sign of leaf droop. Too dry soil can harden and water will run through without actually permeating the soil. Use a hand rake to break up dry soil before watering. Under-watered plants drop leaves to help the plant survive. Roots swimming in water may rot and the plant will shed its oldest roots first. Stop watering immediately. Test the soil by sticking your finger in to the second knuckle. Pull out some dirt. If you can roll it into a ball and squeeze water from it it's too wet. If it won't roll into a ball it's too dry. If it rolls into a ball, but you can't squeeze water from it, it's just right.

Heat and Light

A plant sitting by a window easily overheats. Too much sunlight can sunburn the plant. Try to find a place where room temperature remains stable, between 65 and 85 degrees. Direct sunlight yellows and burns leaves.

Pests

Clear the pot of leaves and debris, which can feed and shelter bugs. Wipe the leaves on both sides with a damp cloth to help it breathe better. Check for bugs. spider mites, mealy bugs and scale. Wiping the leaves with a rag damp with alcohol helps kill aphids, scale and mealy bugs. Gently scrub or scrape the leaves to remove scale and bug deposits. Cut away badly infected foliage. Mist with houseplant insecticide or a solution of 1 tbsp. dishwashing detergent per quart of water.

References

• Plant Care: Peace Lilies -- Why Do They Get Brown Tips
• The Garden Lady: Caring for Sick Peace Lilies
• The Flower Shop Network; Brown Is a Good Color For Chocolates But Not For a Peace Lily; Jamie Jamison Adams
• Iowa State University Reiman Gardens; Lily Brings Peace of Mind; Linda Naeve; Dec. 29, 2003