What Time Of Year Do You Plant Garden Potatoes

growing potatoes

Photo by: Kevin Lee Jacobs.

Potatoes are generous plants. They are easy to grow and produce abundant harvests. Give them the following and they will accept almost any planting situation:

Full sun
Loose, fertile soil
1" of water per week

You can grow potatoes in containers, pots, or a special "grow bag". But in my experience, containers like these require constant attention to watering, and yield smaller harvests than growing in a raised bed.

RELATED: Raised Bed Gardening

I achieve an enormous harvest—enough to feed two for nearly a year—by planting potatoes in two 4'-x-8' raised beds. The tubers are wildly productive in the well-draining, rock-free soil the beds provide, and the vines require deep watering only once each week.

Of all the root vegetables I grow, it is the potatoes that give me the biggest thrill at harvest time. I love to stick my hands in the soil and retrieve the buried bounty, with a yield of eight to ten potatoes for every one that I plant.

However you decide to grow your potatoes, the planting directions are the same.

seed potato

Photo by: Kevin Lee Jacobs.

Step 1: Choose Seed Potatoes

Start with organic, certified disease-free seed potatoes obtained from a catalog or farm store. (Grocery store potatoes that have been treated with a sprout-retardant are not suitable for planting.) If you buy from a farm store, as I do, try to select tubers which have already sprouted. Otherwise, pre-sprout them by simply laying them out on your kitchen counter. Pre-sprouted potatoes can be harvested a few weeks earlier than their non-sprouted kin.

potato eyes

Photo by: Kevin Lee Jacobs.

Step 2: Separate the Eyes

Only small, golf ball-sized potatoes should be planted whole.

Cut large tubers into pieces. I cut mine so that each segment has two or three "eyes" (the little bumps from which sprouts emerge, as shown in the photo). The reason for cutting the potatoes is because the many eyes on a large potato will create a crowded, multi-stemmed plant, with each stem competing for food and moisture, and in the end, bearing only small potatoes.

curing potatoes

Photo by: Kevin Lee Jacobs.

Step 3: Cure the Cut Pieces

Next, "cure" the cut pieces. Either set them out in the sun, or place them on a table or counter in a warm (about 70°F), moderately lit room for three to five days. This step permits the cuts to become calloused. Calloused seed potatoes will help prevent rot.

planting potatoes

Photo by: Kevin Lee Jacobs.

Step 4: How & When to Plant Potatoes

Plant seed potato segments cut-side down (eyes up) in a 6-inch-deep hole or trench. Space each segment 12-inches apart on all sides.

Between each segment, sprinkle 2 tablespoons of a low-nitrogen, high-phosphorous fertilizer. Then cover both potatoes and fertilizer with 2-inches of soil, and water the soil well.

When do you plant potatoes?

This will vary depending on where you live. Gardeners in warm climates often plant around Valentine's Day, while those in cooler areas may get them into the ground near Easter, or early spring. A good rule of thumb is to aim for 3-4 weeks prior to your last frost date.

hilling potatoes

Photo by: Kevin Lee Jacobs.

Step 5: Hill Around the Stems

Because new potatoes form on lateral stems, or "stolons" above the seed potato, it's necessary to "hill" the vines. When the green sprouts achieve 8 inches in height, bury all but their top 4 inches with soil, chopped straw, or shredded leaves. Hill again when potato plants grow another 8 inches. The more you hill, the more prolific your harvest is likely to be. I usually hill mine to a height of 18 inches. Stop hilling when the vines flower.

Potato tubers, like vampires, need to live in darkness. In fact, they will turn green if exposed to light. And a green potato can cause sickness if consumed. Therefore it is absolutely essential to keep the tubers covered with soil or mulch.

potato flowers

Photo by: Kevin Lee Jacobs.

Step 6: How & When to Harvest Potatoes

Two weeks after the vines have flowered, you can, if you wish, reach into the soil or mulch and retrieve a few baby potatoes. Otherwise, wait until the vines die back. Dead vines signal that the tubers have reached maturity. Now reach into the soil with your hands and pull the tubers up.

How long do potatoes take to grow? Small new potatoes can be ready as early as ten weeks. However, full sized potatoes take about 80-100 days to reach maturity.

harvesting potatoes

Photo by: Kevin Lee Jacobs.

Step 7: Store Your Potatoes

Since my potatoes are grown for storage, I leave them in the ground until cool weather arrives. Why? Because potatoes will only store well if they are placed somewhere cold, but not freezing. The closet in my mudroom doesn't cool off until the outside temperatures plunges to 45° at night. So harvest time for me is usually a sunny day in late October.

After digging the tubers, I let them sit on top of the raised beds for a few hours to dry, as illustrated. This brief drying-period toughens their skin, and prepares them for storage. Then I gently brush off any loose soil from the tubers, and place them in double thicknesses of paper bags.

More potato growing tips:

If you don't want to bother with hilling, plant your potatoes 8-9 inches deep. The downsides are: the potatoes take longer to sprout and your harvest might be smaller.
Potatoes like slightly acidic soil (5.8-6.5 pH). Add fertilizer or composted manure for best results.
When growing potatoes in containers, a good soil recipe is 1 part peat moss, 1 part organic potting soil and 1 part cow manure.
If you want to make the task of weeding easier (and you have the space), plant your potatoes at least two feet apart so that you can weed around them easily.

Preventing Potato Blight

The dreaded fungal disease known as the "potato blight" (Phytophthora infestans) was responsible for the Irish potato famine and can destroy your entire crop, too. To reduce the chance of infection, never plant potatoes (or tomatoes and other members of the nightshade family, such as eggplants or chili peppers) in the same patch of land without leaving an interval of at least three years. Also, promptly remove any volunteer potatoes that emerge in your garden. The disease overwinters in tubers left behind during the previous year's harvest.

RELATED:
How to Start a Vegetable Garden
How to Grow Tomatoes
Growing Peppers
How to Grow Beans