Lug tires will help. A wet hil can be a challenge no matter what. Can you cut on an angle to help with the traction? I am not sure what model you have, but you can buy sets at a good price on ebay. I put 4 on mine. 12's in the back 6's up front. Weights are key as well. I have weights inboard 52 lbs.each wheel and outboard 50 lbs each wheel. Ad to that my 200 lbs., I am good to go. I do have a nice lawn and you can not tell I use lugs. "Nothing runs like a Deere"

Changing to a lug tire or ATV tire will greatly improve traction.I had a Simplicity Landlord last year and put 489XT's(6-ply) on it filled with windshield fluid and made a world of difference.It'd climb a 30°bank until the front end lifted off the ground.The XT's won't mark as much as bar lug tires either.
I still have these tires and they're like new.If somebody here needs them,let me know as they're just taking up garage space now. 23X10.00X12
locknut..Indiana

I have super-turf tires... more aggresive, but not a lug tire. If you are afraid to mark up your smooth lawn, you may wish to consider these. I used to slip on the slope in my ditch, but not any more.

{{gwi:317776}}

Wheel weights are by far the easiest route. I was in your shoes five years ago. The first order of business was to install wheel weights and then see if I needed to go with a more aggressive tire tread. Five years later, and I'm still running with the original tires -- the weights did the trick!

Jay
2001 JD GT225
42C Deck

If you have turf saver tires, well, they are about the slipperiest tires out there. Just about any other tread (except no-treads & rib-tread) will increase your traction. Wheel weights or loading your tires will make a BIG difference in traction, perhaps all you need. Weight will increase traction more than just changing your tires (except, perhaps super lugs)IMHO.

t