It wasn't until I bought my first house and was planning the garden for it that someone asked me why I was going to plant anything. It was the first time that I felt like I had to justify the time and space used for gardening. I talked about the food that my family canned (salsa) and froze (green beans). They were so much better than what was at the store, in terms of both flavor and healthiness. We'd also have a stockpile of fresh food going into winter.

"So you're one of those preppers? Do you think the world is going to end?"

When that was the follow-up question, I was actually offended for a minute. I might have been offended the rest of the week. It's funny to think about because I would probably take it as a compliment now. At the time it felt like an insult along the lines of "you're paranoid and crazy, and live in fear of the world ending". I'm not any of those things (moments of crazy not withstanding), but there are so many reasons to grow your own food other than civilization might collapse. It took a while for me to organize those reasons in my head and figure out which were actually important to me. I'd say the biggest reasons for having a garden are the cost savings and enjoyment. Secondary to that is the variety, health benefits, and availability.

I like to use a tomato example to show the cost benefits of gardening.  A roma tomato at the grocery store is around 32 cents, or $1.29 per pound. A package of seeds (250 seeds) is less than $5. A single roma plant will produce around 25 pounds of fruit.  So for $1, I can either grow myself 1,250 pounds of tomato OR buy just under one pound from the store. (Math check: $1 = 50 seeds, 50 plants x 25 pounds per plant = 1,250 pounds). The same thing goes with many other vegetables and fruits that you can buy at the store. I'm not going to eat 1,250 pounds of tomatoes straight off the vine every year, but what if I turned that into pasta sauce, salsa, curry, or soup? Suddenly I have a whole pantry of meal staples from that $1 of seeds.