Every year my grandpa (Papaw) asked me, "Did you plant your potatoes on St. Patrick's Day?" and I usually said no. Eventually, I started to do just that, so I could give him a big smile and say yes! And after his passing a few years ago, I vowed to plant at least my first set of potatoes on St. Patrick's day - no matter what the weather was like. I've planted in the rain, in pure mud and even once in the snow! Usually, these potatoes give me the best crops, so thanks Papaw!
It is recommended that you use seed potatoes to put in the garden and I used to do that. But honestly, now I just use whatever potatoes have gone too far (with big gnarly sprouts), which always happens to me because I buy organic potatoes. Organic potatoes are not treated with a synthetic sprout inhibitor (a chemical cocktail that prevents cell division) which is used on regular potatoes to lengthen shelf life in the grocery store. I still get really good yields, it means less waste and I know the potatoes were organic. I just leave the potatoes whole and plop them in the ground.
Potatoes don't like to be planted too deeply because they rot easily and the perform best when immersed in nutrient-rich compost and my beds are perfect for this. See my post on prepping the garden beds for details. Another important piece of advice is to rotate your crops each year. This reduces the chance of having pest and disease problems that you may have experienced the previous season. Potatoes belong to the Nightshade family (Solanaceae), but so do peppers, tomatoes, and eggplants. Keep this in mind when you plan where to plant what each year. Many members of this family of plants contain chemical compounds that can be toxic at low levels, but nightshade foods are just fine, though some people have sensitivity to them. Solanine is a chemical that is present in potato tubers. When potatoes are exposed to sunlight in the garden, they develop green spots that contain higher levels of solanine, which can be toxic if too much is ingested. Just make sure to keep them covered during the growing season and you have nothing to worry about though. I usually throw some mulch over the tubers whenever I see anything exposed, but the green part can be cut off and the rest of the potato is just fine.
Potatoes are tubers, which are modified stems. This is where the starch (nutrients) is stored when they are not actively growing. The roots will grow down and the shoots will grow up. Place the potatoes on the soil surface, with the buds pointing up. If the poatoes haven't sprouted yet, don't worry - they will "figure" it out themselves.
Cover them with soil and a thick layer of mulch - no need to water at this point, but if it is a dry season, make sure to water them a couple times a week. You can use compost, straw or just extra soil if you don't have anything else. There are numerous methods to growing potatoes, such as in a 5 gallon bucket (with drainage holes) or in an old tire. Experiment and use your favorite method!
Now we wait. Before long, you will see the shoots emerge and the flowers will bloom. When the flowers and stems begin to wither, you can start harvesting. Early harvests will give you tender young new potatoes, or you can leave them in the ground a little longer to grow larger and firmer. When you have your first fresh baby potato, you'll ask yourself why you never planted them before. When the time comes, I'll share my favorite recipes with you. The easiest and tastiest is simply drizzling with olive oil, salt and pepper and roasting them. They are so creamy and luxurious.