Depends on how fast you want to get up and running.
At this point in time there is no way to tell whether the battery will survive having sat dead for as long as it has. A discharged battery will self destruct the plate material if allowed to sit dead for more than a couple of months.
Recharging a battery that has completely discharged requires that the battery be recharged rather slowly, and for a relatively long period.
For your battery, a charge rate of about 3 amps is ideal and you should charge it at 3 amps for about 3 full days.
Then, take the battery to an auto parts store and have it load tested, repeat LOAD TESTED, not just a simple voltage test.
If you don't feel comfy with auto parts store personnel, take it to a bona fide battery dealer. But, a 3 day 3 amp charge should be followed by a load test if you want to be sure.
Or, you can charge the battery for 3 days at 3 amps and then just try it and see if it starts.
Or........go the fast route and just buy a new battery.
That way you are 3 days ahead of finding out if anything else (like the fuel system) survived the over winter storage.
If you buy a charger, get the kind that automatically cuts back on the charge rate as the battery gets near the fully charged point. That way you will not overcharge and boil the battery dry.
Your choices, your call.

I don't know the specific details of your mower, but some only have headlights when the engine is running.

You might want to take it to a battery shop and explain the details. They can give it the proper charge & test it. Likely this would be free or a minimal charge in hopes of selling you a new battery.

IF you live in a very cold climate and your garage is unheated, it may be a moot point. The electrolyte in a fully discharged battery is basically water and will freeze. That depends on how discharged and how cold.

I'd just replace the battery and be done with it. If it sat that long discharged the battery is most likely done anyway. You'll probably spend close to what the battery is worth in gas taking it to a shop and then going back to pick it up.

Agree with ckr, replacement battery is what, $30-40? No more hassles and no worries for a year or so. Replacement doesn't have to be "green," just fit the holder, connections line up, and rating is equivalent or higher.

Did you run the gas tank dry last fall? Add stabil or equivalent to the gas? Depending on where you live and the type of gas that sat in it over the winter, you may have fuel circuit issues to deal with. If you're new to the "care and feeding" of small engines, the new gas/ethalyne mix creates issues. VERY good idea to put Stabil or equivalent in the can prior to buying gas to preclude this.

Good luck,

Ev

I believe I am going to offer the minority opinion. If it were mine, I would move the tractor over to the car, and jump start the tractor.

If you can not jump start the tractor there is more wrong than the battery.

If it starts, unhook the cables and mow the yard. This will give the battery sufficient charge to start it the next time. The battery may give you several years of service postponing the cost of a new battery. (With a new house you have better things to spend your money on.)

Then again the battery may have to be replaced,

For winter storage, I would get a trickle charger, (I use a cheap charger from Walmart) and periodically put the battery on the charger for several hours. It the tractor is stored in a shed, and you experience extreme cold, I would bring the battery in to someplace that will not be subject to the cold, (When the battery is discharged it can freeze, as when discharged there is more water in the battery. When charged there is more acid in the battery, lowering the freezing point.) Assume standard auto type battery.

NOTE: If you jump start the tractor MAKE SURE YOU FOLLOW ALL OF THE PRECAUTIONS. Make sure the tractor and the car are the same voltage. Make sue you connect negative to negative, positive to positive. MAKE SURE YOU DO NOT GROUND THE BATTERY. If you have never done this google and read complete instructions.

I am posting a generic photo guide (again) that graphically illustrates the proper way to safely jump start a vehicle.
The sequence of connecting the jumper cable alligator clamps needs to be followed exactly (1-2-3-4) and pay close attention to the fact that step #4 is showing the connection IS NOT TO THE BATTERY POST. Connection #4 is to a part of the vehicle chassis or engine ground AWAY from the battery.
When removing the jumper cables, remove them in the reverse order (4-3-2-1)

I'm having the same issue. OEM lasted 3 years. Replace with a DL which died and wouldn't hold a charge after a little over a year (tractor was garaged and used for plowing.) Current battery was replaced last Spring (tractor still garaged but no longer plow with it) Dead this Spring. Did jump start, but did not build enough charge to re-start the tractor.
Will have it load tested just in case I get lucky.
My question is: As the cheapest batteries run $40. and up and only have a 3 mo. warranty, is there a recommended inexpensive battery that is more reliable than the DL?

FWIW, My brother and I have had good luck with the batteries from WalMart for the smaller tractors, go carts, etc. Provided they'll fit and the connections line up. I think we've probably bought four or five over the last three or four years.

Ev

I have used batteries from Walmart and paid about $30 for many years. I keep the tractor in an unheated shed in the yard, BUT bring the battery into the garage and periodically put it on a charger as I said above.

I usually get 3 to 4 years on a battery.

Thanks for the respones. Battery ended up passing the load test, so I get a reprieve. I'll check out Walmart the next time I need to replace it.

Mownie: Your battery connection illustration is inaccurate. Steps 1 and 2 should be reversed. In other words, the initial connection should be the red wire to the DEAD battery (see all the other illustrations and instructions). Otherwise, it's a good chart. (Like so:)

Oh boy. I can't wait for mownies response in 4 or 5 years on this! In May of '14, he was vacationing down under- so naturally the reds would be reversed. Just like the reverse toilet water spinning thing...

Jeff, it is only inaccurate if it is considered in a "time and motion" sense of logical steps.

In that view, I will agree that connecting the red cable to the dead battery first, then connecting the other red cable end to the donor battery second, then connecting the black cable end to the donor battery third, and then arriving back at the vehicle needing the boost to connect to a good ground OTHER THAN the negative post of the dead battery.............will accomplish a safe boost with the LEAST steps between the 2 batteries or vehicles.

But from a strictly "SAFETY" view of the differences between the steps I posted initially, and the revised steps you posted.......either way is equally safe insofar as minimizing the occurrence of a spark or arc directly on the battery.

I did not look at the task from a time and motion point of view when I posted my version and in fact I had not really considered that detail back in the day, but your version does accomplish the same safe hook ups, with just 1 trip between the 2 batteries (for attaching) and 1 trip for detaching the jumper cables.

Equally safe but with fewer steps.