Having leaves on your lawn can be seen as a message to the rest of the neighborhood that you just don't care. There are many schools of thought on this. Some people say that having leaves on your lawn will kill the lawn and promote rot and mold. Others say the decaying of the leaves helps the lawn get important nutrients. If you live in Florida you may not have this issue, however throughout the Midwest and Northeast deciduous trees will also cause headaches for homeowners' lawns in Nashville, TN.
After all, Mother Nature put the leaves there, Mother Nature can take them away too. The problem is your lawn did not evolve to have the leaves there, nor did the trees evolve to put them there. It is like putting two different species together and expecting them to somehow make a new baby.
According to the National Gardening Association, many rake their lawns because they worry that the lawn will be killed if it is still growing. The truth is that the lawn is dormant over the winter, so there is little worry concerning growth. As well, when spring comes along, leaves tend to decompose anyways.
On that same note, those wet, decaying leaves in the spring (if not dealt with immediately) can prevent your lawn from getting adequate sunlight. That does kill the lawn. When the leaves are dry and crunchy, they can easily fly away and it is not a problem. Wet, soggy leaves are a big problem though.
What is the best option then?
Well, as it turns out, it is a mixture of keeping your leaves on the lawn, and getting them off.
In the Autumn, when the leaves are on your lawn, rather than rake them, deal with them using a lawn mower. The dry leaves will be swept up into the lawnmower, where they will be chopped up into tiny pieces (hence how dry leaves are best). Once chopped up, the leaves will be spread over the lawn in tiny little pieces. This helps the lawn two-fold.
First, it prevents the leaves from collecting in a pile and killing the lawn underneath in the spring, while promoting rot.
Second, it gives your lawns the nutrients from the decaying leaves, which are scattered all over the lawn.
The third, best benefit, is that you no longer have to take several hours raking up the leaves.
Of course, the downside is you can't jump into a pile of leaves at the end.
So, the answer to keeping your leaves on your lawn comes down to a little from column A and a little from column B.