Caring for Sick Peace Lilies

TheGardenLady received this question from Linda.

I have a peace lily indoor plant which has sentimental value to me and over the past winter it has contracted a leaf condition – the leaves die from the tip towards the stem.  It’s as though a critter is “sucking” the life from it. It still flowers, but I am afraid as more and more leaves are infected I will lose the battle. Any suggestions?

TheGardenLady has to assume from your brief email that you have not changed anything in your plant’s environment- you haven’t moved your plant or changed the lighting, temperature, humidity or care. Usually most brown tips are caused by low humidity. And I also have to assume that you had not re-potted your Peace Lily Spathiphyllum improperly or put it in poor soil.

Or your Peace Lily might have to be re-potted. Sometimes a plant that has been in the same pot for a long time has a build up of salts in the soil from fertilizers and alkaline tap water. When you re-pot your plant, be sure you do not re-pot it too high or too low and use good potting soil (see here).

Peace Lilies are tough plants but they can have problems. Taking good care of your peace lily will mean it’s less likely to suffer from problems like pests. It is important to keep the pot free of dead leaves and debris. You should be cutting out the dead leaves. Wiping the leaves – upper and lower sides – from time to time with a damp cloth helps the plant breathe. And you should check to see if your plant is free of the pests that infect these plants which you may have brought into the house, unbeknownst to you, when you brought in a new plant.

Some of these pests that attack the Peace Lilly and other plants are spider mites, mealy bugs and scale. You should check your plant carefully to see if there are these pests. For photos of pests of plants check out this.

If you do have the problems with pests, remove the plant from near any other plants and also check the other plants for these pests to remove from the vicinity of healthy plants.

Should you notice tiny webs at the underside of your leaves or in leaf axils, you could have spider mites. Wash by hand but use dish soap and water, about 1-2 tablespoons to the gallon is enough. Use warm water and wash thoroughly. If pests are seen or thought present, wash with dish soap weekly for 3-4 weeks checking the plant all the time.

If you have mealy bugs, a dilute solution of water and rubbing alcohol sprayed on leaves will kill these pests. The bugs turn brown in color and you can wipe them off. Be sure you use only a little alcohol. The alcohol approach can work against scales and aphids as well.

Scale is the most difficult problem to deal with, especially on houseplants. Scale insects are often difficult to control and there is no, easy simple cure for a scale infestation. TheGardenLady hopes you don’t have scale. If you do, try to pick off individual scales or gently scrub (or rub) the scales loose from the leaves and stems. This is a laborious task that works only on small, large-leafed plants. Dabbing each scale with an alcohol-soaked cotton swab is another possibility on lightly infested plants.

Sprays can be used for scale but success will depend upon thoroughness and persistence. Aerosol or hand pump insecticide sprays made just for houseplants are available at garden centers. Or you can try a mild dish washing detergent- again use a dilute solution of 1 Tbs of detergent per quart of water. Soap sprays can be applied with a sprayer or used with a soft cloth while washing infested leaves and stems.

Peace Lillys are generally free of diseases. If one over waters the plant, it could get root rot, but you would see a rotting root and smell an awful rotting smell.

Without seeing a plant, it is tricky to make a diagnosis. Good luck in saving your plant.