She's a clever girl

As we were driving to church today:

KK: I spy something that starts with the letter "L". It's outside and we are passing it right now. There is some right over there.
Sparky: Uh. . .lights?
KK: Actually, it starts with the letter "T", but when you get a bunch of them together then it starts with the letter "L".
Me: Leaves!
Sparky: Yeah, leaves.
KK: No, but leaves are part of it when they are still on the things that start with the letter "T".
(At this point we were all stumped)
Sparky: I don't know.
KK: Landscaping!!