The MLL which is the major league outdoor lax is in the summer and its not always on but if it is it'll be on ESPN2.
The NLL which is the major league indoor box lax isnt usually on TV it all depends on the market cause it's not as popular in the other team markets like it is in buffalo and rochester. but the championship game is usually broadcasted. That runs in the winter months I think the first weekend is the last weekend of the year.
College lacrosse starts in the spring and the championship game is memorial day weekend.
I love the sport it's played very differently in each league which can be confusing to people not used to it. Outdoor lacrosse is much more open with a bunch more players, indoor (or box) lacrosse is played in a hockey arena with less players and is just as if not more physical than hockey.