Is there an NPC I can hire or create that will do my farming for me?

Solution 1:

If you have the into the future expansion, you can create a plumbot and give it Gardening Software, which gives it maximum gardening skill and even includes an unlimited amount of the best fertilizer and will prioritize gardening over other actions.

You still have to choose which plants to plant but aside for every week or so when plants die and need to be replaced you won't have to mess with it.

Solution 2:

I had this problem myself- visions of a beautiful healthy garden- just didnt realize I'd be in it from sun rise to sun set. Unfortunately, no, you have to tell one of your controlled sims to do the work. Sprinklers is a good 1st step, but if it's taking too long still, you might want to narrow your garden down to 1 type of each plant. Then you can make use of the 'Tend Garden' and 'Fertizile Garden' options; while your sim is still doing the work, one command applies to every plant. Gardening is serious business in The Sims- if you follow it through, which you are doing now- (good luck with the Omni, I got as far as Steak and Egg plants and rolled another town), one skill can take up all your time in the game

Solution 3:

There is a mod called Gardener Service that will use your home phone (not cellphone) and then a gardener (or two if you have bigger garden) will come and take care of it every day. It works with the latest patch but hasn't been uptaded for Seasons so you have to manually cancel the service when the frost kicks in and no gardening can be done. You can find it on modthesims.