How long does the spawning season last for Largemouth Bass?  What factors determine the length of the spawning season?

LMB, Spawn in the spring(of course but it is not the only time)... Water temperature is the main key factor in spawning bass. It not only determines when they spawn it also will determine at what depth they spawn at. In Ohio LMB start to per spawn at around 60-63Dergrees F. Give or take a degree or 2. The full spawn isn't really going on until the water temperature is 64-69Degrees (again give or take a few). You will find them mostly in the shallows but some larger bass in clear lakes will spawn at pretty deep depths. 10-20ft. and usually earlier then the rest of the other smaller LMB(again depending on temp.).. Most of the times you will find the nests at 1-6ft.

Hope this Helps!

JJ

The spawn can last up to 3 months

There is no single controlling factor and as to what those factors are no single person has yet to completely understand all the factors that apply.

List of generally accepted factors

Sunlight penetration

Water clarity

Water depth

Water temperature (not surface temperature)

Gestation period

Weather conditions

Each individual bass

That's seven before my brain disengaged

Thanks for the input fellas

The BULK of our spawn in the North lasts roughly a week.  Sunday, we found a small handful of beds and then yesterday, the place had exploded overnight.  Same thing happened last yr but it happened the night of the moon,...a little early this yr.

By the end of next week (provided the temps stay stable) they will be done and off the beds.