Puckering Leaves: but not the kissable type

Asked October 16, 2020, 11:50 AM EDT

Hello, I have a 3 year old Peace Lily plant which I adore, however for at least a year now I have noticed long puckered streaks on both old and new leaves. The puckers or wrinkles.. (I will include photos) will eventually pull on the leaf enough that it tears/rips and eventually destroys it.
I can think of nothing different that I did or has happened during the time this began happening. I have searched every leaf with a magnifying glass and see no indications of mites or bugs. I changed the plant pot and soil, I started keeping the window blind closed on the side closest to plant in case it was too much sunlight, I keep the leaves cleaned at least bi weekly. I took an effected leaf to the agriculture department in my area and everyone is as puzzled as I am. Help please!


Maryland

1 Response

This damage appears to be abiotic, meaning it was not caused by a pest or disease but rather by environmental conditions. Based on the symmetry in the folds, it looks as if this damage occurred while the leaf was still emerging/unfurling. Low humidity is a possible cause, given that air-conditioned and heated air in homes results in very low humidity which can hard on tropical plants. Among other side effects, this can affect how leaves unfurl from their rolled or folded emerging state, causing creases or tears. Some tropical species naturally exude a slight sticky residue (generally termed "exudate") from their leaves when they are newly expanding/unfurling, which can act as a natural adhesive if it doesn't dissipate on its own or get rinsed away (as it might in rainfall in nature). Since leaves expand to their full size primarily by absorbing water, any lack of sufficient moisture during this process can cause kinks in the leaf as it expands unevenly; the same with any exudates that temporarily prevent the leaf from expanding evenly if portions of it are stuck together. The kinks remain even after the environmental conditions improve because leaves do not "heal" from damage and cannot change shape after they have formed.

Although it causes aesthetic damage, this is not a threat to the plant's health overall, though adequate humidity levels will minimize the plant's stress in other ways. (We do not have research data on what exact levels are needed, but as a rough guideline, around 50% is probably sufficient.) If needed, a room humidifier can help raise ambient humidity levels if several houseplants are sharing the same space.

Dusting the leaves with a damp cloth is good, but if you use a "leaf shine" product, make sure not to apply it too often based on how frequently the label directions say it can be used, as you do not want to over-expose the plant to its chemicals. [This puckering is probably not phytotoxicity (damage to tissues from chemical exposure - organic or otherwise) but it is a general risk if a pesticide or any other treatment is applied too often or differently than label directions.]

Overall, the foliage in the pictures looks to be in very good condition, so other than monitoring it for watering needs to make sure it doesn't get too dry between waterings, no actions need to be taken. You can resume giving it the normal amount of light it received before the blind was closed (especially now that the days are shortening and it's getting less light overall) as this does not look like sunburn.

Miri