I know leaves do not emit inferred so should not trigger an inferred sensor, but also know mine are triggered so will guess there is some inferred light which they are reflecting, however it is the sensor which matters, and stand alone are always better.
We tend to call safety lighting, security lighting, not sure I want to help an intruder by lighting his way, I am quite happy to watch him walk into things in my garden, with the exception of milk man, and since he calls at approx same time every time a light on a timer works fine, it also connects to wifi so I can switch it on/off from phone when I get home.
But a 12W LED bulb in the bulkhead lamp is not going to break the bank in running costs, so simply not worth having on a PIR.
Because leaves are reflecting inferred light, if there is light they can reflect not much you can do, same as cat or badger in the garden, they will trigger the lamp. My old one had three adjustments, sensitivity, light level, and time it stayed on for, but any human dressed up for the cold does not emit much inferred, specially wearing face masks, and if I reverse up my drive, the lights are not triggered until I have got out of car and am nearly at the house, but the trees still trigger them, so I intend to use wifi switches on the all, as they are not for intruders they are for me.
As for intruders we close curtains at night, so would not see lights come on anyway, and leaving on attracts insects, which in turn attracts the bats, which are very distracting as they fly past the window, and do trigger the PIR's so if we leave the outside lights on, they flash on/off all night as insects are attracted by light from windows which in turn attracts bats.
