Peace Lily Has Bugs And Black Tips With Holes Starting

Question:

I was wondering if the bugs that are in the peace Lillie also damage the plant?  The tips of the leaves turn black before they unwind and bloom.  What causes this?  The leaves also have a hole started in it.  We had trouble with the plant and the nursery recommended an organic fertilizer.  The pot now has many bugs and fruit flies.  Plus it still didn’t bloom.  So we cut all the leaves short to 1 1/2 inches and now that they are starting to sprout they have black tips and are starting to get holes in them.  How do I fix this and get my blooms back?

Answer:

The folks at your local nursery don’t know what they are talking about, but they do know how to sell product! Fertilizer (organic or otherwise) is not medicine. It is intended only for healthy plants that are growing vigorously. Over fertilizing is a much more common problem than under fertilizing.

Fungus gnats (fruit flies)and black leaf tips are both clear signs of root rot usually caused by not allowing the soil to dry out sufficiently between waterings. Repotting of Peace Lilies is also a  common reason for root rot. The extra soil added acts like a sponge and retains water for too long and deprives the roots of oxygen. I hope you did not make this most common of all plant care mistakes. If you did, let me know and I will try to help you with it.

You will now have to remove any loose soil on the top surface. This extra soil serves no useful purpose but it does harbor most of the fungus gnat larvae. So removing that top layer of soil is the first step in treating he gnats. Do not replace the soil that you remove. Removing the excess soil will also help the air penetrate into the root zone more readily.

You will also have to cut back on your watering frequency. Wait until the leaves start to wilt just a bit before adding any water, no matter how long that takes. When you do water, add just enough so that it reaches the wilt point again in about a week. You will have to experiment a bit with the water quantity to determine how much your plant requires. No doubt, it is less than you realize.

Allowing the soil to dry out sufficiently every week will deprive the gnat larvae of the damp soil they require to live and it will also allow more oxygen into the roots and help counter the root rot.

Peace Lilies sold today are all hybrids cultivated to bloom profusely at point-of-sale, but re-bloom sporadically and weakly thereafter. To encourage flowers, the plant has to be very root-bound with healthy roots. Repotting discourages flowering and plants with ailing roots rarely flower.

The holes are due to root damage, not bugs.