Basil with deformed leaves - need help

[vfx]

I have a very large Basil plant that I inherited from a friend. I don't know how old it is but it is over 2 feet tall and the stems are woody. It was growing beautifully for about 2 months, but lately it has been having problems. All the new leaves have been coming in dark green and deformed. They have jagged edges and are curled. The underside even looks deformed. These leaves look nothing like any of the older leaves. I have searched everywhere, but cannot find answers on this problem. Now leaves are falling off a lot and I don't know what to do.

Does anyone have any idea what it might be, and what I can do?

[Jess]

Do you have your plant indoors or outside?
Basil is very susceptible to whitefly attack which can cause a lot more damage on a plant indoors than ouside where the natural predators have a better chance of eating them.
Whitefly can cause deformity of the leaves as can thrips and spider mite. If you cannot see anything chances are it is spider mite as they very tiny.
Can you see anything on the underside of the leaves?

[anthony22]

Hi there. Reviving this thread from the dead.

I, too, have a basil plant with woody stems. It's about 2 years old and has always lived indoors. The leaves have slightly jagged edges (the edges were previously smooth) and there's nothing underneath them (I think). I've tried putting in new soil which helped but now even new leaves are showing the jagged edges.

[rainbowgardener]

A picture is worth a thousand words!!