Producing food, year round, to feed yourself/family is actually insanely difficult. Small scale farming that provides year round is no small task and generally not considered “good” advice for prepping. Do that if you want to supplement sure but you’re going to die if your only source of food is the garden in your yard. Farming is a very labor intensive and resource consuming, highly contextual skill that requires highly specific knowledge with a huge variety of variables that can also just flat out fail through no fault of your own, it’s not a safe plan for survival.

Long term shelf stable foods like rice, beans, grains, pastas, canned goods, canned protein, dried goods, dried spices/seasoning and salt all need to be stocked before you consider growing fresh food as part of the equation. Also canning/preserving food will be a huge task if you plan to rely on your own grown food, which is in and of itself a time consuming skill that requires the correct tools and knowledge to do well and safely.

If the time comes that your only food option is home grown food you’re as good as starved in basically the entirety of the US and I’m sure most other developed nations. If you happen to live in an agricultural valley that has actual real, dedicated farms with farmers who actually know how to produce food at scale you will survive longer but it will still be very difficult and social connections would likely serve you better than wasting all your time and energy working a yard garden that produces a measly haul, go spend that time doing what the farmer needs so you can barter.