This is the eleventh in our biweekly series from Amy Pennington – urban farmer, founder of GoGo Green Garden, and author of Urban Pantry and Apartment Gardening – on how to start growing your own food, no matter how tiny your garden-to-be is.
Today: Growing potatoes couldn't be easier -- as Amy explains, it's all in the bag. Literally.
Growing potatoes is a pretty mysterious undertaking. All of the harvestable bits of the plant grow underground, making it hard to keep track of progress. Even though I've grown potatoes in the past, I'm consistently amazed when baby potatoes appear in the soil at harvest time.
To grow a potato, you basically cut a small piece off of a seed potato (a potato specifically designated as seed for planting, versus a potato you buy in the store) and bury it under a few inches of soil. The plant will eventually send up a stem and leaves, and as the plant grows we cover them (always leaving a little bit of leaf showing) in order for the plant to produce more potatoes. Pretty simple. This process, when done in a field, is called "hilling up" potatoes, as farmers will form hills of soil around the potato stem to maximize production.
Potatoes in the great outdoors
In small urban gardens, this task becomes difficult as we often don't have much space to begin with. Or maybe, like me, you only have a small balcony. Fortunately for all of us, potatoes can be grown in bags — or boxes or garbage cans for that matter. Essentially, any container in which potatoes can grow vertically while we cover their stems and roots will work.
Before we get started, a few quick notes about potatoes:
• Potatoes do not like super hot weather -- for Northern gardeners, now is a great time to get started. For Southern gardeners, you'll have to wait until the heat of summer begins to wane, or try putting your potato bags in a cool, shaded spot that only gets morning sun, such as the north side of a garage or a north-facing balcony.
• Sweet potatoes and potatoes are different plants, but can be grown in the same manner. (Remember that they take longer, about 3 months.)
• Choose a quick-growing potato variety for your bag. Remember all those seed sources we talked about a few weeks ago? They're great resources, as is your local nursery.
• Finally, for this plant-in-a-bag project I prefer a better-looking bag. Burlap sacks and plastic woven feed bags are a bit more shabby-chic than the bag your soil is sold in. Try your local coffee roaster or country feed store; these often have the added benefit of vintage-looking logos — a great way to add character to your urban garden.
For more on potatoes and how they're grown, you can find more in this post on Feed52. And now, here's potatoes in a bag — know it, love it.
1. Purchase organic seed potatoes and a bag of potting soil.
2. Cut each potato into smaller 1 to 2-inch "seeds" — each seed should have 1 to 3 "eyes." Set the seeds on a countertop or windowsill for a day or two to dry out. This helps minimize rot during the growing process.
3. Empty 2/3 of the soil bag into a storage bin, a large terracotta pot, a garbage bag, or another large, handy receptacle. (You'll end up using this portion of the soil for covering the potato stem.) This leaves you with 1/3 of the soil still in the bag — now, fold or roll down the sides of the soil bag so you end up with container-bag about a foot deep. (Check out Feed52 for more on how you can use simple straw to hill your potatoes.)
4. Place the seed potatoes, eyes facing up, about 2 inches deep into your soil. It's easy -- just press them in and call it a day.
5. Pierce or slash your potato bag in several places to allow for drainage, but be careful not to make too big of a hole. You don't want soil spilling out!
6. Water lightly. The best way to tell if your potatoes (or any plant, for that matter) have enough water is to stick your hand into the bottom of the bag. The soil should just barely hold together due to dampness, but it should not be wet. As you continue to water over the coming weeks, be sure to NOT overwater your plants! Overwatering and then drying out the soil will produce imperfect potatoes with knobs and hard, dense skin.
Demonstrating how to roll up the sides of the bag -- even though these are just planted!
7. After a few weeks, the potatoes stems will have grown about a foot tall. Now is the time to unroll a length of your potato bag and cover the entire stem with fresh soil (or hay***), leaving the leaves uncovered. If the stems grow tall enough, you can do this once more during the growing season.
8. When flowers start to bloom on your potato plant, it's a good indication that you've produced baby potatoes (also called "new potatoes" -- these are the same teeny new potatoes you see at the farmer's market). You can harvest potatoes from your plant now, if you'd like!
9. After the flowers bloom, the potato vines will yellow and die back. Leave plants for another week or so before harvesting (potatoes are still developing inside that bag). To harvest, line your patio or deck with newspaper and cut open the sides of the bag. (Soil will spill out, which you can reuse for lettuces or herbs.) Harvest the potatoes and let them "cure" for two days — this simply means laying them out to dry, which helps to develop the skin. Then cook them as you like!
And now it's time to get growing -- keep us posted on your bags!