Potatoes, Solanum tuberosum
This article is a complete guide to growing your own potatoes from certified seed stock. Below you'll find a number of explanatory videos and photographs. But if you're just looking for a quick reference then we've got you covered:
|Average Seed / oz||Seed / 100' Row||Average Yield / 100' Row||Days to Harvest|
|NA||10 lbs||100 lbs||60-120|
|Planting Season||Ideal Soil Temp||Sun||Frost Tolerance|
|Spring/Fall||NA°F||Full Sun||Very Tolerant|
|Sowing Method||Seed Depth||Direct Seed Spacing||Seeds Per Packet|
|Mature Spacing||Days to Sprout||Production Cycle||Seed Viability|
The potato is native to the Andes Mountains of South America where it is a perennial plant. It has steadily become a staple of the Anglo diet since its adoption roughly 400 years ago. Research suggests that it may have been domesticated as long ago as 10,000 years by the native people of that region. Potatoes from the Andes come in all colors and sizes. We are just beginning to see some of this diversity on grocery store shelves as well as in seed catalogs. Examples of this diversity include the Austrian Crescent Fingerling and the Purple Majesty that we offer.
If you know what you're doing and just want to buy some certified seed potatoes then we have a range of organic and gourmet varieties to get you growing. We take pre-orders year round, but seed potatoes generally ship in March.
I’ll be honest from the start: I love potatoes. Potatoes are the one food group I could not live without. Stick me on a desert island and I’ll take some seed potatoes and start a farm. Despite the bad rap potatoes have received in some sectors of western nutrition, the potato has a lot to offer. Carol Deppe, in her book, The Resilient Gardener, discusses five main crop types that every resilient gardener should grow. Potatoes are top of the list. Deppe states:
“In temperate regions there is no crop capable of producing more calories per square foot than the potato.”
At Sow True Seed, we sell certified seed potatoes, which are very different from potato seeds. Seed potatoes describe prime quality potatoes grown under disease free conditions and sold for the purpose of growing potatoes. When you grow a potato plant from a potato, you are growing a genetically identical clone. Potatoes do sometimes flower and set seed, but that’s a different article!
Can I use store bought potatoes?
It is worth noting here the risks of growing store bought potatoes. Yes, they are cheaper. Yes, they will sprout (although they are often sprayed with growth inhibitors that will affect vigor). But they have not been grown and monitored to be disease free as seed potatoes. Potatoes are prone to many diseases and you certainly don’t want to introduce them into your garden. Many people do grow store bought potatoes and are successful, but if you do it that way you should at least know and weigh the risks.
Potatoes come in a wonderful assortment of skin and flesh colors with purples, blues, reds, yellows, golds and whites. I believe in diversity between crops, but also diversity within crops. So, plant lots of different varieties and find out what works for your garden and your plate. Early potatoes, such as Red Pontiacs, are often eaten as ‘new potatoes’. They are thin skinned and taste great boiled and eaten with melted butter. They mature early, but often don’t store that well. Yukon Golds are a good example of an early potato that stands up well to being left in the ground for a later storing harvest, making it a good all rounder. Late potatoes are often storage potatoes, they are denser and hold up well through the winter. Kennebec is a classic late season storage potato.
When and How to Plant Potatoes
Potatoes are basically a cool season crop. They like a sunny spot with loose, well-draining soil so that the roots and tubers can develop. Potatoes do not need super-rich soil, but enjoy some organic matter and a balanced (or slightly lower) pH. As a root crop they'd appreciate some phosphorous, adding bonemeal at planting time can help with yields. The well known (and easily remembered) planting date for our region is St. Patrick’s Day, but you can certainly plant earlier and later to spread your harvest window. For other areas the planting should occur about 3-6 weeks before the last killing frost date for your area.
Prior to planting, you’ll cut the seed potato into sections. Each section wants to be about the size of an egg with 3 or 4 eyes. The eyes are where the potato sprouts grow from. If the potato is already sprouting, this isn’t a problem, but be careful not to break them during planting. Some people will cut a couple of days prior to planting and let the potato heal over, this can help with disease and rot. Good rotation is essential for preventing disease. Do not plant where nightshades have been planted in the last four years.
Here are some tried and tested planting methods:
Trench Method – Dig a shallow 6" trench and plant the potatoes with their "eyes" facing up. Cover with 1"-2" of soil and continue to build soil up around the sides in "hills" as the potatoes grow. This keeps the soil loose for growth while preventing exposure to sunlight which creates solanine that turns potatoes green and somewhat toxic. Stop hilling up soil when the plant develops flowers and add a few inches of straw around the plants to help conserve moisture.
Scatter Method – Simply scatter the potatoes right on the soil and cover with 1"-2" of soil, adding more soil and mulch as the potatoes grow. This is not a good option if you have issues with rodents, but is good if you have issues with drainage.
Container Method – Place about 6" of soil in the bottom of a container (tall planter or garbage can with small holes in the bottom for drainage), place plants inside and simply continue to add 1"-2" of soil and straw as they grow.
Potatoes grow best in acidic soil (pH 5.0-6.0) with plenty of well rotted manure and organic matter. The soil should be well drained so that the spuds stay drier, reducing the incidence of disease.
The plants will flower (or sometimes not) and then begin to die back. Discontinue hilling once the plants begin to flower or die back. They will be ready for digging about two weeks after the dieback. Dig potatoes gently, with hands or a fork. Avoid bruising them. Ideally you’ll harvest after a dry period, but if potatoes are wet allow them to dry prior to storage. There is no need to wash potatoes before storing, but you will need to eat damaged ones as they won’t store well. With proper care you can expect as much as 10 times the yield of what you planted (1lb can become 10lbs).
Common Potato Diseases
Check regularly for signs of insects and disease. The Colorado Potato Beetle usually finds its way to most crops. Luckily the brightly colored orange/yellow eggs on the underside of the leaves are easy to find and squish. Beetles can be hand collected (chickens will love them!) and removed from the crop as an initial control. Plants can also be covered with row covers to prevent beetles from landing on the crop in early spring. Here is an image chart for identifying the Colorado Potato Beetle.
Late blight, the disease that caused the Irish Potato Famine can be a challenge as well. It enjoys cool temperatures and moist conditions throughout the growing season and causes water soaked spots on leaves of potato and tomato crops. Good air circulation and early drying of dew off leaves each day helps prevent the spread of the disease. Never touch leaves while they are wet and prune out diseased areas quickly. If you anticipate a problem with late blight you can find more information on this disease through your local Co-operative Extension Service.
Potatoes from year to year
Potatoes are one of those crops where the seed to seed part is pretty easy. We’re not dealing with sexual reproduction, so there is no worry about cross pollination. Plant and save as many varieties as you want. Because you want to store potatoes for eating, it is easy to keep a few back for planting the following year. Keep the potatoes in a cool (35-40F) and dark location with moderate humidity and ventilation. I store separate varieties in labeled paper bags in my basement. If stored properly, potatoes can keep for up to 8 months.
The additional step for saving seed potatoes for planting is to closely monitor for disease. You can do this during planting, growing and harvesting. Don’t be tempted to risk planting a potentially diseased potato. Check for plant damage, abnormal growth, skin blemishes - anything that would suggest it’s different to the norm. Feel free to eat these, but don’t use them as seed stock! And then follow Deppe’s three rules for disease prevention:
“Rotate. Rotate. Rotate.”
Comments Contest is Now Closed
Enter our comments contest for a chance to win an Asheville-made bar of Gardener's Soap (for after potato planting!) and a set of Wooden Plant Markers (so you can keep track of all your colorful potato varieties!). Just leave a comment below answering the question: How do you like to eat your potatoes? A winner will be selected at random on Thursday March 1st.