When growing anything, my ideal plant is one that can be put into the dirt and ignored until I want something from the plant. When growing vegetables, potatoes are close to perfect. It can be as easy as putting them in some dirt, then ignoring them until 2-5 months later when you want to eat potatoes.
Many people say that soil should be mounded up around potato plants. This is called “hilling” and there are tools to make the job easier (which means it’s lots of work). I’m partial to gardening methods that require the least amount of effort while yielding maximum results. Carefully hilling extra dirt around my potato plants every week does not fall into the “least amount of work” category. Fortunately, potatoes are much easier to grow than all the effort required to build a small mountain around every potato plant.
First, realize that not all potato plants grow the same way:
- determinate – grow in one layer, so there is no point in mounding soil around the plants; usually produce an early crop (70-90 days)
- indeterminate – can produce multiple layers, so hilling soil around plants can significantly increase the yield; usually produce a late crop (110-135 days)
Early (determinate) potatoes can be sown about 4″ deep in very loose soil. After the plant emerges, mulching heavily will help inhibit weeds and will protect the potato tubers from being exposed to sunlight. Sunlight causes potatoes to turn green and toxic, so mulching is important.
Late (indeterminate) potatoes are good candidates for growing in potato towers/boxes. The best plans I’ve seen for building a potato box are here. Put soil down and toss in potatoes; cover with 4″ loose dirt. When the plants are about six inches high, add three inches of soil or straw or hay or dry leaves (potatoes aren’t picky), leaving part of the plant exposed. As the potato plant grows, continue adding new layers of soil/straw/leaves; new tubers will grow at every level that soil is added. Note that boxes are not necessary for late potatoes; these spuds can be grown in traditional rows, but you use more space to grow fewer potatoes so it makes sense to grow them in towers.
Fingerling potatoes are determinate, regardless of how many days it takes them to mature.
Unlike beans and zucchini that can get too big and tough if not harvested at exactly the right time, potatoes can be ignored. When the potato plant is done growing, it will die. Some people say to wait about two weeks for the potato peels to cure. Others dig potatoes right away and let them cure in a cool, dry place. The potatoes don’t care, and I refuse to be a slave to my garden (it serves me; I don’t serve it) so I harvest them whenever it’s convenient.
To harvest potatoes grown in a tower, simply unstack the tower and pick up the potatoes. When you unstack the tower, it might be a good idea to have containers handy for the extra soil.
To harvest potatoes grown in rows, use a digging form (similar to a pitchfork, but with wider tines) to dig well out from where the now-dead plant was growing; gently lift the dirt to look for potatoes.
It’s possible to harvest new potatoes from healthy, green plants, just reach beneath the plant and dig around in the dirt. I like to grab three or four baby (new) potatoes from every plant, leaving plenty to mature.
Do not waste manure or good, fresh compost on potatoes. Doing so will produce fantastic looking leaves, but that is not your objective. Save the compost for lettuce, corn, and other things that grow above ground.
Older soil (not freshly composted/manured) is great for tubers. It needs to be loose, not compact (no clay). It also needs to be well-drained. Potatos will rot if the ground is too wet.
Most potatoes from the grocery store have been chemically treated to inhibit sprouting. Even if they get old and sprout, they don’t yield a good potato crop. Visit a nursery and buy “seed potatoes,” which are untreated potatoes that have begun to sprout. My favorite nursery sells seed potatoes in April (when it’s time to plant); in mid-May, when potatoes are supposed to already be in the ground, the price on seed potatoes drops to 50% off (and there is no problem with planting them late enough to get the price break).
The potato “seed” that is planted is really a sprouted potato. At least two eyes are needed. If you have a larger seed potato with many eyes, you can cut the potato into 2″ chunks and plant the chunks separately. After cutting, let the potatoes sit for a day before planting; this will give the cut edges time to dry and form a seal so that the seed produces a new potato plant instead of rotting. Some people prefer to use tiny seed potatoes that can be planted whole. Although it’s easier than cutting potatoes into chunks and having to wait a day to plant them, it is not recommended. If you plant small potatoes, you grow small potatoes. If you plant cut-up big potatoes, you’ll grow big potatoes.
Which Kind to Plant
Choose potato varieties based on what you want to cook.
- Baked potatoes, mashed, fried: Choose potatoes with a very high starch content and low moisture content, which makes them ideal for baked and fried potatoes but mushy in potato salad. These are known as “mealy” potatoes. These potatoes tend to have a coarse-appearing skin and include Russets, Butte, Rose Gold, and Mountain Rose (to name a few).
- Soup, potato salad, casseroles, scalloped potatoes: Choose potatoes with a low starch and high moisture content. These are perfect for boiling because they don’t absorb much of the cooking liquid. Low-starch potatoes are known as “waxy.” The moisture content is too high to make good bakers or fries. Waxy potatoes tend to have a very smooth skin. Varieties include Purple Viking, All Blue, Onaway, and Red Norland.
All-purpose potatoes have an in-between moisture and starch content. Experiment to see which varieties you prefer. Yukon Gold, Peruvian Blue, German Butterball, Yellow Finn, Superior, Kennebec, Red Cloud, Bintje, Elbe, Caribe, and Katahdin are a few of the all-purpose varieties.
The waxy/mealy categories have no correlation whatsoever to whether the potatoes are determinate/indeterminate. Ideally, a garden would have a few rows of mealy early potatoes, a few rows of waxy early potatoes, and a tower or two each of mealy & waxy late potatoes. Throw everything in the ground and cover with about 4″ of soil. About 3-4 weeks later, mulch rows if you haven’t already. Add soil to towers every 2-3 weeks after that, depending on how quickly your plants grow. It takes very little work.