Potatoes are one of the most productive crops a home garden can grow. A single 10-foot row can yield 10 to 25 pounds of tubers, and the variety depth available from seed catalogs leaves grocery store options looking sparse. They do ask one specific thing: hilling. Keep tubers covered with soil throughout the season and you get clean, flavorful potatoes; let them see sunlight and they green up and become bitter. Get that habit down and potatoes are remarkably forgiving.
When to plant potatoes
Potatoes are a cool-season crop and tolerate light frost better than most vegetables, but they need soil temperatures of at least 45 to 50 degrees F at planting depth for reliable sprouting. That puts the window at roughly 2 to 4 weeks before your last spring frost for most gardeners. Too early in cold, wet soil and seed pieces rot; too late and the heat of summer cuts yields short.
For a fall crop in mild climates, count backward from your first fall frost by the variety's days-to-maturity plus 2 to 3 weeks for harvest and foliage-die-back. Fall potato timing is tighter, but worth it for a separate storage harvest.
Soil and site
Potatoes thrive in full sun (6 to 8 hours minimum) and well-drained, loose soil. Heavy clay holds too much moisture around tubers and invites disease; sandy loam with plenty of organic matter is ideal. Target a soil pH of 5.8 to 6.5, slightly acidic, because alkaline soils encourage potato scab.
Work in a few inches of compost before planting to improve drainage and feed the long season. Avoid fresh manure, which can also promote scab. Good drainage and a slightly acidic pH are the two soil factors that matter most.
Seed potatoes: what to buy and how to prep
Always start with certified disease-free seed potatoes from a reputable seed supplier or garden center, never grocery store potatoes (which may be treated to prevent sprouting and can carry disease). Certified seed stock is inspected and free from common viral and bacterial pathogens.
Preparing your seed pieces
Choose your variety
Early types like Yukon Gold and Red Norland mature in 70 to 90 days; late-season types like Russet Burbank need 100 to 120 days. Pick based on your season length and intended use (waxy varieties for boiling and salads; starchy for baking and frying).
Cut large tubers
Cut any seed potato larger than a small egg into pieces, each containing at least 1 to 2 "eyes" (the budding points) and roughly 1.5 to 2 ounces of flesh. Small tubers can be planted whole.
Cure cut pieces
Spread cut pieces in a single layer at room temperature for 1 to 2 days so the cut surfaces callus over. Calloused pieces resist rot in cold soil far better than freshly cut ones.
Planting
Plant seed pieces cut side down in furrows 3 to 5 inches deep, spaced 10 to 12 inches apart, in rows 30 to 36 inches apart. Closer spacing (around 9 to 10 inches) produces more smaller tubers; wider spacing (up to 15 inches) pushes the plant toward fewer but larger ones.
If you are growing in a raised bed or container, the same 10- to 12-inch in-row spacing applies; just make sure the bed is at least 12 inches deep for room to hill and for tubers to develop without crowding.
Cover seed pieces with soil, firm gently, and water in. Shoots should emerge in 2 to 3 weeks depending on soil temperature.
Hilling: the non-negotiable step
Hilling is the practice of mounding soil up along the stems as plants grow. It matters for two reasons: it keeps developing tubers covered so they do not turn green (green potato flesh contains solanine and is mildly toxic), and it gives tubers more loose soil to expand into, which often improves yield.
How and when to hill
First hilling
When stems are 6 inches tall, pull 3 to 4 inches of soil up around the base, leaving only the top few inches of leaves exposed. A garden hoe works well for pulling soil from between rows.
Second hilling
When plants reach 12 inches, repeat, mounding soil further up the stems. By this pass you will have covered much of the stem below the leaf canopy.
Total goal
Aim for 6 to 8 inches of hilled soil total around each plant by the end of the process. Do not hill after plants flower, as tubers are already sizing up.
Watering and feeding
Potatoes need consistent, even moisture, roughly 1 to 2 inches per week, especially during tuber set (the flowering period). Irregular watering during bulking causes knobby, misshapen, or cracked tubers. A soaker hose delivering slow, deep moisture at the root zone is ideal.
Back off water significantly once the vines begin to yellow and die back. Wet soil at harvest leads to disease and poor storage. Stop all water about 10 to 14 days before you plan to dig.
For feeding, potatoes respond well to a balanced organic fertilizer worked into the soil at planting. Once plants are a few inches tall, a side-dress of a vegetable fertilizer supports the long growing season without pushing excessive leaf growth at the expense of tubers.
Common problems to watch
Colorado potato beetles are the most consistent pest: large yellow-and-black-striped beetles and their reddish larvae devour foliage fast. Scout every few days and pick off egg masses (orange clusters on leaf undersides) before larvae hatch. Flea beetles riddle new foliage with small holes and are most damaging on young plants. Wireworms damage tubers underground and are hard to manage once present; rotate away from grass-preceded beds.
On disease: early blight shows up as dark lesions with concentric rings on lower leaves; late blight, the historic famine pathogen, causes water-soaked lesions that spread rapidly in cool, wet weather. Both are managed with rotation, adequate spacing for airflow, and prompt removal of infected material. Potato scab roughens the skin and is reduced by keeping soil pH below 6.5 and watering evenly during tuber set.
Harvesting and curing
New potatoes (small, thin-skinned, eaten immediately) can be dug 6 to 8 weeks after planting, usually once plants have flowered, by carefully reaching into the hill and pulling a few without disturbing the main plant.
Full-size storage potatoes are ready when the tops have fully yellowed and died back. Wait 10 to 14 days after dieback before digging; this waiting period thickens the skins for better storage.
Dig carefully with a garden fork, inserting it at the outer edge of the hill to avoid spearing tubers. Lift, brush off loose soil, and spread in a single layer in a cool, dry, shaded spot (not the sun) for 1 to 2 weeks to cure. Cured potatoes store for months in a cool (38 to 40 degrees F), dark, humid space.
Potatoes in the rotation
Potatoes are heavy brassica-rotation partners in the sense that they share important rotation rules: never follow themselves or other nightshades (tomatoes, peppers) in the same bed for at least 3 years. Both early and late blight, plus soil-borne pathogens, build up quickly without rotation. See the crop rotation guide for a practical rotation schedule.
When should I plant potatoes in spring?
Plant seed potatoes 2 to 4 weeks before your average last spring frost, once soil temperature at planting depth reaches 45 to 50 degrees F. Colder, wetter soil causes seed pieces to rot before sprouting. Look up your frost date on the frost dates tool and count back from there.
Do I have to hill potatoes?
Yes, if you want clean, edible tubers. Hilling keeps developing potatoes covered with soil so they do not turn green. Green potato flesh contains solanine and should not be eaten. Start hilling when stems reach about 6 inches tall and repeat until you have 6 to 8 inches of soil mounded around the base.
Can I grow potatoes from grocery store potatoes?
It is strongly discouraged. Grocery store potatoes are often treated with a sprout inhibitor and may carry virus or bacterial diseases that spread to your soil. Certified seed potatoes from a garden center or seed supplier are inspected, disease-free, and reliably viable. The difference in germination rate and plant health is significant.
How do I know when potatoes are ready to harvest?
For storage potatoes, wait until the vines have fully yellowed and died back, then wait another 10 to 14 days before digging. That waiting period allows skins to set, which dramatically improves how long potatoes keep. For new potatoes, you can harvest small tubers carefully as early as 6 to 8 weeks after planting once plants have flowered.
Why are my potatoes small or knobby?
Irregular watering during tuber set (the flowering period) is the most common cause. Potatoes need steady moisture, roughly 1 to 2 inches per week, while bulking up. Drought followed by heavy rain causes growth cracks and knobby shapes. Wide spacing (12 to 15 inches) also gives each plant more room to produce larger individual tubers.