Flax leaves shriveling up

Question

I have what I believe is a Flax plant in my yard and many of the leaves dry out and shrivel up. Any idea why and what I can do to make it stop?

Answer 1

New Zealand flax (Phormium) tend to do this if they are in a very windy and dry situation, or after winter - it doesn't kill the plant, but its not attractive, obviously. It's usual to just cut out at the base leaves which are damaged or dead - best done with very sharp scissors.

Just check the smaller plant though - look right at the base of the leaves, pulling them apart to see if you have a Phormium mealybug infestation, see here for images http://oregonstate.edu/dept/nurspest/ground_mealybug.htm. This pest does affect growth, causing it to be stunted and with more die back on the leaves. If it is present, you need to source an insecticide that will treat for it - malathion works, but has been withdrawn in some countries. It needs to be sprayed at the base, inside the leaves by moving them aside to reveal as much as possible of the white fluff, and will likely need to be repeated annually in spring. If you do find this pest, check your other Phormium too. It is not necessary to spray the whole plant, just the affected areas.