Connected might be the wrong word. It doesn't have to be like this:
According to the MinecraftWiki:
In Beta, leaves decay according to a simple formula: leaf blocks decay unless they are within 4 blocks of a log block, and connected to the log by other leaf blocks.
should be fine. Not sure what'll happen to something like
Since I've provided you with the information that there's a MinecraftWiki, please use it next time you have a question. Word of caution: I've seen much wrong information on the wiki. You'll have to try things out.
Private Mod Note
Rollback Post to RevisionRollBack
This signature is now 20% cooler. That's what I'm counting on.
yeah what i wanted to know is if theres a mod to stop it.... or something similar....
The only thing I can think of is to edit your texture pack so you're replacing the texture for one material with that of leaves (white wool, maybe?). That way you can place a load of "white wool" and it'll look like a leaves block