I've had a request from a reader to discuss my method of growing potatoes. I've grown every kind of potato there is, it seems, and in every different way I can. Over the last few years I've definitely found my favorites, and I'm happy to share them with you!
First of all, you don't need to buy seed potatoes from a seed house, unless you are wanting a specific variety that you can't get at your local market. As long as you buy organic potatoes, you can wait until those go soft and sprout, and then plant them. Conventional potatoes are sprayed to prevent them from sprouting, so buy only organic for this purpose. (Heck, for any purpose. Potatoes regularly make the Dirty Dozen list for high-chemical residues.) My local Whole Foods carries organic Russet, Yukon Gold, and both small red and fingerling potatoes, sometimes even blue. Any of these will work. Like I said, if you want something more specific, you'll have to order from a seed house. That's fun too, but I like using up potatoes that have gone soft in my vegetable bowl.
Once you have your sprouted potatoes, you can either cut them, leaving a couple of eyes on each piece, or leave them whole. Frankly, I don't bother with the cutting. If you cut, then you have to wait several days to let them dry and harden, and I honestly usually just want to get them in the ground. Planting them whole is fine, though if you have unlimited space, it's more efficient, and you'll get more yield, if you cut them.
I've grown potatoes in every season. In the hot summer months, they seem to prefer dappled shade in my zone 9b garden (very hot and dry, and often windy), or morning sun only. The full sun just burns them up. They will grow through our colder months (it's mild, here) in full sun, but I don't get a harvest until spring. Mainly it seems I am harvesting potatoes either in the spring or the fall. Potatoes regularly come up voluntarily in every section of my garden, as I've grown them in all different places, and clearly missed some at harvest-time. Sometimes I pull them out when they sprout, for instance if they are coming up in tomato beds, because I don't want any diseases spreading between those two plants in the same nightshade family.
My first potato experiment was growing them in towers. I had read that if you have a limited amount of growing space, this is a good way to still have potatoes. Pretty much anyone can find room for a 2x2 basket of some sort, with an open bottom. You simply lay the mesh cylinder on the dirt, then place the potatoes at the bottom. Cover them with dirt. Line the sides with newspapers so that the dirt doesn't fall out. Wait until the plants have grown about a foot, and then add more dirt up to the bottom of the leaves. As they grow, keep adding more dirt until you reach the top of the cylinder. The potato plant will shoot out the top and then topple over a bit. That's fine.
I got a great yield from this method. The potatoes grew along the stem of the plant but also down deep into the dirt below, so there were potatoes in the cylinder and below the cylinder. I pried apart one side early on, and harvested new potatoes as soon as I saw blooms, and then waited to harvest the rest of them when the plant died. It was textbook.
A word here about potato blossoms. I have gotten a potato harvest even if I haven't seen any blooms. I can't explain that. I don't know why. It seems I am not the only one to question this; when I search for answers, I do find that not all potato varieties need to flower to produce fruit. In fact, some flower some years and not other years. It seems there is a great deal of leeway when it comes to flowering. So don't rely on the flowers to tell you whether or not there are potatoes below - you should be able to pull back your mulch (whether it be dirt or straw or leaves) and see what you've got. In any case, when the vines die back, it's time to dig out the harvest.
I've also grown potatoes in rows, using straw as my hilling material. There's a couple of reasons to hill potatoes. One, covering up the developing tubers keeps them protected; potatoes exposed to light can turn green and poisonous. Two, hilling keeps the developing roots cool and covered. Three, hilling helps drain water to the sides so that the potatoes get what they need but don't sit in puddles. The good news is, you can use pretty much anything to hill your potatoes. Dirt is probably best, but dirt is sometimes in short supply (like in my raised beds, which have a finite amount of soil). Ruth Stout was the person who first wrote about hilling potatoes with straw. She believed in 'no work' gardening, and she advocated tossing your potatoes directly onto dirt and covering them with a layer of spoiled old hay. I find that I like my potatoes to grow a bit of green first, so they don't have to work their way through a matted straw flake, then I toss the straw on top and work it towards the sides of the plant. It works great. A lot cheaper than soil, too.
I get better yields when I plant in rows, but only by a little. It does take up a lot of space, so you'll have to decide space vs. yield, for your needs. I think you could probably make a tower with straw instead of dirt, as well.
Which I tried last year, and I think it worked ok, but the problem is that I planted the potatoes in 10 gallon pots. I don't think the potatoes had a lot of room to spread out and grow properly, like they did in the open-bottomed mesh cylinder. If you search 'growing potatoes in containers,' you'll get all kinds of folks raving about how well it works for them, whether in pots or grow bags. Frankly, it didn't work well at all for me. The plants looked great, but the yield was the smallest by far. I was very disappointed.
Nutritionally, russets have more to offer than the gold potatoes; fingerlings are better than the reds, surprisingly, and the blue potatoes have some interesting extra nutrients that the others don't have. Make sure you eat all the skins! All potatoes are energy-rich, meaning they are fairly high in calories, and can be a calorie-staple crop for those who can store them properly. Around here, it's nearly impossible to do that, so I only grow as many as we can eat within a month. Potatoes prefer dark, cool, ventilated, humid conditions - like a root cellar. I don't know anyone that has a root cellar in CA (and if you do, can I rent a shelf???), so I spread them out into a single layer, then dry them in a shady place for a day or two. If it's winter and it's cool, I can keep them in a bin in the house, but again, not for terribly long. If it's summer, I put them in a paper bag in the garage refrigerator, with a bowl of water nearby for humidity. It's not perfect. That's why it's a good thing to grab a few every few days as they are growing, rather than waiting until the end for a large harvest.
As for pests, we do get the potato beetle here. When I find them on the plants, I collect them and squish them. I don't find that they do a huge amount of damage. Deer like the green leaves and will eat them to the nubs if they can reach them. Other than that, I don't notice many potato predators. (Though we are starting to see signs of voles around here - I'm working on a post on that - they could do some serious damage; as could gophers, which we don't usually see in our yard, thank heavens.)
My dad often told me that potatoes were one of his favorite things to grow in his extensive garden, it was like a 'treasure hunt' digging them up. I agree. They're fun to look for in the dirt, they have beautiful leaves and flowers, and they provide a tasty meal. I'd say put some in the ground ASAP and by October, you could have a substantial crop!