Potatoes are one of the easiest crops for a home garden: plant pieces of seed potato in spring, keep the developing tubers covered with soil, water steadily, and dig them when the plants are ready. This guide covers how to grow potatoes in the ground, in a container or in a bag, from choosing seed potatoes to curing and storing the harvest. It follows University of Maryland Extension, Iowa State University Extension and the RHS.
Potatoes at a Glance
| Step | What the sources say |
|---|---|
| Seed | Certified disease-free seed potatoes (UMD, Iowa State) |
| Planting time | As soon as the ground can be worked; soil at least 45°F (Iowa State, UMD) |
| Depth and spacing | 3 to 5 in deep, 8 to 12 in apart, rows 24 to 36 in (UMD); 4 in deep, 1 ft apart (Iowa State) |
| Sun | At least 6 hours of direct sun (Iowa State) |
| Soil pH | 6.0 to 6.5; 4.8 to 5.8 where scab persists (UMD) |
| Water | About 1 in a week, steady during tuber development (Iowa State) |
| Maturity | Most cultivars 90 to 120 days (Iowa State) |
| Curing | 50 to 60°F, 85 to 90% humidity, about 2 weeks (Iowa State) |
| Storage | About 40°F, 90% humidity, dark (Iowa State) |
Sources: UMD Extension, Growing Potatoes in a Home Garden (2026); Steil and Jauron, Iowa State Extension (reviewed 2024); RHS.
Seed Potatoes, Cutting and Chitting
Use certified seed potatoes. UMD Extension says to buy certified disease-free seed potatoes from a reputable company, because store-bought potatoes can carry disease without showing symptoms. Iowa State adds that home-saved or supermarket potatoes may carry hidden disease or sprout inhibitors. So you can grow potatoes from sprouted supermarket potatoes, but the results are less predictable.
Cutting: Iowa State says to cut large seed potatoes into pieces with 1 or 2 eyes (buds) each and plant small ones whole. UMD suggests pieces of about 1.5 to 2 oz (roughly 1.5-inch cubes) with 1 to 3 eyes. Let the cut surfaces dry and callus for a few days before planting to reduce rot; Iowa State suggests holding them at 60 to 70°F and 85 percent humidity for several days.
Chitting (pre-sprouting): the RHS suggests setting seed potatoes with the buds facing up in egg boxes or trays somewhere bright and frost-free for about 4 to 6 weeks, until the sprouts are about 5 cm (2 in) long. It says chitting is optional and mainly helps early varieties; maincrop varieties gain little from it.
When and How to Plant
Iowa State says to plant as soon as the ground can be worked in spring; UMD gives March 15 to May 1 depending on location, with soil at least 45°F. Choose a spot with at least six hours of direct sun (Iowa State) and well-drained soil.
- Dig a furrow or trench: 3 to 5 inches deep (UMD), 4 inches (Iowa State) or about 15 cm (6 in) (RHS).
- Set the pieces cut side down, sprouts up, 8 to 12 inches apart (UMD) or about 1 foot (Iowa State), with rows 24 to 36 inches apart (UMD).
- Cover with soil and water well if the soil is dry.
The RHS groups potatoes by how fast they mature: first earlies (ready in as little as 12 weeks, best for small plots and containers), second earlies, and maincrops, which stay in the ground longer and give larger tubers for storage. Its spacing is about 30 cm (12 in) for earlies with rows 60 cm (24 in) apart, and 37 cm (15 in) for maincrops with rows 75 cm (30 in) apart.
Soil, pH and Scab
UMD gives an ideal soil pH of 6.0 to 6.5, and 4.8 to 5.8 where potato scab is a persistent problem. Iowa State notes that scab, caused by Streptomyces scabies, is most common in alkaline soils above pH 7.0, and warns against adding large amounts of organic matter such as manure where potatoes will grow, because it can increase scab. Rotating is the other key: Iowa State suggests planting potatoes in the same area only once every three or four years, and the RHS recommends a different spot each year to reduce soil-borne problems.
Hilling (Earthing Up)
Hilling means drawing loose soil up around the stems as they grow. Iowa State says it gives tubers loose soil to grow in and keeps shallow tubers from turning green in sunlight. The RHS suggests starting when shoots reach about 23 cm (9 in), drawing soil up so only the top 10 cm (4 in) of foliage shows, and repeating every few weeks until the ridge is 20 to 30 cm (8 to 12 in) high. UMD suggests hills no more than 6 inches above grade. The RHS notes that plants still crop if you skip earthing up, but earthing up keeps the tubers out of the light and protects young shoots from frost.
Keep any cultivation shallow so you don’t damage roots and tubers near the surface. A straw mulch also helps: UMD suggests a thick straw mulch to deter Colorado potato beetles.
Watering and Feeding
Water: Iowa State says potatoes need about 1 inch of water a week, and the best yields come from a uniform, consistent supply of moisture while tubers develop. Uneven moisture can cause growth cracks, knobby tubers and hollow heart. UMD says to keep plants well watered if rain is lacking, especially while tubers are developing, and to avoid overhead watering, which can spread fungal diseases.
Feeding: UMD suggests fertilizing before planting and side-dressing about six weeks later, when tubers start to form. The RHS says potatoes in the ground usually need no feeding, though maincrops on poor soil benefit from a nitrogen-rich organic fertilizer around the second earthing up. Don’t overdo it: Iowa State says over-fertilizing can encourage hollow heart. A soil test is the best guide.
How to Grow Potatoes in a Container or Bag
The RHS says early varieties suit containers best. If you want to know how to grow potatoes in a bag, the RHS says grow bags or sacks work well as long as they have drainage holes; the steps are the same as for a pot.
- Use a container at least 30 cm (12 in) wide and deep, and half-fill it with about 15 cm (6 in) of peat-free compost (RHS).
- Plant one seed potato per 30 cm (12 in) of container width, just below the surface.
- Add compost as the shoots grow until it is just below the rim.
- Water regularly all season; containers can dry out even in wet weather because the foliage shelters the compost (RHS).
- Mix a general-purpose organic fertilizer into the compost, or use a liquid feed after about six weeks (RHS).
- At harvest, tip the container out.
To grow potatoes in a bucket, use the same method in a bucket with drainage holes, as long as it is about 30 cm (12 in) across. UMD notes that tall potato “towers” usually don’t work.
Harvesting
New potatoes: Iowa State says you can dig them once tubers are more than 1.5 inches across; UMD says 6 to 8 weeks after planting, usually after the plants flower. The RHS suggests harvesting earlies when the flowers open or the buds drop, once tubers are about the size of a hen’s egg. New potatoes don’t store well: Iowa State says to refrigerate them and use them within ten days.
Storage potatoes: Iowa State says most cultivars mature 90 to 120 days after planting. Dig a test plant after the vines die: if the skin is thin and rubs off easily, the potatoes aren’t mature. UMD suggests leaving the tubers in the ground for two weeks after the plants die back so the skins thicken. Dig carefully, starting well away from the stems, to avoid cutting or bruising tubers. Iowa State gives 20 to 30 pounds per 10-foot row as a good yield.
Curing and Storage
- Cure: hold the tubers at 50 to 60°F and 85 to 90 percent humidity for about two weeks to heal small cuts and thicken the skin (Iowa State; UMD gives 10 to 14 days).
- Sort: store only sound, undamaged tubers; use damaged ones first (RHS).
- Store: at about 40°F and 90 percent humidity in the dark (Iowa State); UMD gives 40 to 50°F and says they can last 6 to 8 months.
- Not too warm, not too cold: above 50°F, tubers start sprouting after 2 or 3 months; below 38°F, they turn sweet (Iowa State).
- Keep away from fruit: ripening fruit gives off ethylene, which promotes sprouting (Iowa State).
Common Problems
| Problem | Cause | What to do |
|---|---|---|
| Rough, corky patches on the skin | Common scab, worse in alkaline soil (Iowa State) | Lower pH if high, avoid heavy manure, rotate every 3 to 4 years |
| Cavities in the center of large tubers | Hollow heart from rapid growth (Iowa State) | Avoid over-fertilizing; cut out the discolored part |
| Cracks or knobby tubers | Dry spell followed by heavy water (Iowa State) | Water evenly |
| Green skin | Light exposure (Iowa State, RHS) | Hill well; store in the dark; discard green parts |
| Leaves stripped by striped beetles and red larvae | Colorado potato beetle (Iowa State, UMD) | Hand-pick beetles, eggs and larvae; straw mulch |
| Small round holes in tubers | Wireworms (Iowa State) | Little control in home gardens; rotate |
| Brown, collapsing foliage in wet summers | Blight (RHS) | Act quickly; don’t store blighted tubers |
| Blackened leaves after a late frost | Frost damage (Iowa State) | Plants usually regrow; no need to replant |
Sources: Steil, Iowa State Extension, Managing Potato Diseases, Disorders and Pests (reviewed 2024); UMD Extension; RHS.
Potatoes are related to tomatoes; for a different summer crop, see our okra guide, and for building garden soil, our composting guide.
For more herbs and edibles, see our guides to creeping thyme.
Frequently Asked Questions
Can I grow potatoes from sprouted supermarket potatoes?
They may grow, but UMD and Iowa State recommend certified seed potatoes because store-bought ones can carry disease without symptoms or be treated with sprout inhibitors.
How deep do you plant potatoes?
About 3 to 5 inches (UMD) or 4 inches (Iowa State), with pieces about 8 to 12 inches apart. The RHS uses trenches about 15 cm (6 in) deep.
How do you grow potatoes in a container?
Use a container or bag at least 30 cm (12 in) wide and deep with drainage holes, plant one seed potato per 30 cm just below 15 cm of compost, and add compost as the shoots grow (RHS).
When are potatoes ready to harvest?
New potatoes once tubers pass 1.5 inches (Iowa State), often around flowering. Storage potatoes after the vines die back, usually 90 to 120 days after planting (Iowa State).
Are green potatoes safe to eat?
Cut off and discard green parts. Iowa State says green tissue has higher glycoalkaloid levels and can upset the stomach.
How do you store potatoes after harvest?
Cure them at 50 to 60°F and high humidity for about two weeks, then store at about 40°F and 90 percent humidity in the dark, away from fruit (Iowa State).
Sources
- University of Maryland Extension: Growing Potatoes in a Home Garden (updated 2026)
- Steil, A. and Jauron, R. Growing Potatoes in the Home Garden. Iowa State University Extension (reviewed 2024)
- Steil, A. Managing Potato Diseases, Disorders, and Pests. Iowa State University Extension (reviewed 2024)
- RHS: How to grow potatoes