Gary,

Look at it this way:

Those white leaves seen in infrared-photography employing that Wood-effect are nothing else but strongly over-exposed subject areas. That this does not end in an image overexposed in general, is due the fact that those leaves reflect IR-radiation much! more than any other part of the subject. (Without use of that IR-filter those other subject parts would be even more over-exposed than those leaves due to the sensitivity of the film to that other light which is so much higher.)

Using a green filter, how strong it would be, on a non-IR film would not yield that effect as other parts of the subject still reflect green light, and not that much less than those leaves.

That very selective reflection of IR-radiation is the thing behind that kind of IR-photography.