Phal narrow leaves
 

I noticed that the new leaf on my phal is narrower than the previous leaves. It happened to my three phals..all the new leaves are narrow and I don't know what's the reason. Thank you guys..

Did you move the plants to stronger light ever since it grew the previous leaves? In lower light the leaves tend to be much wider so that the plant has a greater surface area with which to absorb light. In higher light the leaves usually grow out narrower, since they don't need all that extra surface area. My phals did exactly this when I moved them to a sunnier windowsill.

Yes camille, the plants receives high light. Should I worry about the narrow leaves? Thank you.

I've also seen this due to the plant being stressed. My Phals with known root problems have done this then as then once the roots are healthy again the new leaves have come out wider.

If you are definately giving it higher light then I would not worry as that sounds like the reason, but it never harms to check the roots if you haven't recently or if you have any reason to suspect problems.

On an otherwise healthy plant, the narrow leaves are perfectly normal in higher light conditions. I take it as meaning that you have found the plant's happy spot!