How to Plant Seed Potatoes (Chitting, Depth, Spacing & Hilling Guide)

Seed potatoes are one of the most satisfying crops to grow at home: plant in spring, hill a few times, and dig up more food than you put in the ground. The process is simple, but a few specific steps — chitting, cutting and curing, the right depth, and consistent hilling — decide whether you get a bucketful or a disappointing handful.

This guide covers every step from choosing certified stock to knowing when to dig.

Quick answer

Chit seed potatoes eye-end up in a cool bright spot for 4–6 weeks until sprouts reach 1–2 cm (0.5–1 in). Cut large tubers into egg-sized pieces with 2+ eyes each, cure cut pieces for 24–48 hours, then plant 10 cm (4 in) deep, 30 cm (12 in) apart, sprouts facing up. Hill soil up around stems every 10–14 days. Harvest new potatoes at 60–70 days; main crop at 90–100 days once foliage dies back.

Step 1: Start with certified seed potatoes

The single best investment in a potato crop is buying certified seed potatoes rather than replanting kitchen spuds or uncertified tubers.

Certified seed potatoes are grown under inspection and declared free of major potato diseases including late blight (Phytophthora infestans), potato virus Y, and blackleg. That disease-free starting point matters because most serious potato problems are soil- or tuber-borne — you import them with what you plant.

What to look for when buying:

• A certification label or tag from your state or provincial seed authority
• Firm, plump tubers with visible dormant eyes — not shrivelled, green, or rotten
• The variety name, so you know whether you’re growing early, mid, or main-crop potatoes

Variety classes by maturity:

Class	Days to harvest	Best for
First early	60–70 days	New potatoes, small gardens, containers
Second early	70–80 days	Medium-sized crop, less blight exposure
Main crop	90–100+ days	Maximum yield, best for storage

If you have a short growing season or a history of blight in your area, first and second earlies are much safer choices — they’re in and out of the ground before late blight peaks in late summer.

Step 2: Chit (pre-sprout) your seed potatoes — 4–6 weeks before planting

Chitting means deliberately sprouting the seed potatoes in a cool, bright spot before they go in the ground. It is the step most first-time growers skip, and it is the step that makes the most visible difference.

How to chit:

1. Place each seed potato eye-end up in an egg box, seed tray, or flat tray — the eye-end is the end with the most indentations (eyes).
2. Put the tray somewhere cool — 7–10°C (45–50°F) — with bright indirect light. A windowsill, an unheated greenhouse, or a cool porch all work well.
3. Leave them for 4–6 weeks until each eye has pushed a short, fat, purple-green sprout of about 1–2 cm (0.5–1 in).

What you want: Short, stocky, dark-coloured chits — purple or green. Long, pale, stringy chits grew in the dark and snap off too easily. If yours look pale and leggy, move them to a brighter spot.

What chitting does: A chitted potato planted in the ground already has an established sprout system. It emerges from the soil faster, develops roots more vigorously, and reaches harvest one to two weeks earlier than an unchitted tuber. In a cool-climate short season, those two weeks can be the margin between a good crop and frost ending things early.

Step 3: Cut large tubers and cure the cut pieces

Small seed potatoes — roughly egg-sized, about 50–60 g (1.5–2 oz) — are planted whole. Larger tubers should be cut to get more plants from your stock and to reduce the risk of rotting in the ground.

How to cut:

• Use a clean, sharp knife. Wipe the blade with dilute bleach solution between cuts to avoid spreading disease.
• Cut each large tuber into pieces roughly the size of a large egg, making sure each piece has at least 2 healthy eyes.
• Avoid tiny scraps with only one small eye — they won’t have enough energy reserves to establish strongly.

How to cure:

After cutting, do not plant immediately. Lay the cut pieces cut-side up on a clean tray in a dry, well-ventilated spot at room temperature — about 15–18°C (60–65°F). Leave them for 24–48 hours.

During curing, the cut surface dries and forms a corky callus layer. That callus is the barrier between the starchy interior of the seed piece and the moist soil — without it, the piece can rot before it sprouts. This step takes almost no effort and prevents the most common cause of seed potato failure.

Step 4: Prepare the soil and trench

Potatoes prefer:

• Loose, well-drained soil — sandy loam or amended loam is ideal. Heavy clay causes waterlogging and encourages rot and scab.
• Slightly acidic pH — 5.5 to 6.5. Alkaline soil encourages common scab.
• Full sun — at least 6 hours of direct sunlight per day.
• No fresh manure mixed into the bed immediately before planting — it causes scab. Well-aged compost or rotted manure dug in the previous autumn is fine.

Dig a trench 10–15 cm (4–6 in) deep and flat-bottomed. A flat-bottomed trench means all seed pieces sit at the same depth, which gives a more even crop. If you’re planting multiple rows, space the trenches 60–75 cm (24–30 in) apart.

Sprinkle a handful of balanced slow-release fertilizer (5-10-10 or similar) into the bottom of each trench and mix it lightly into the base soil.

Step 5: Plant at the correct depth and spacing

Place each chitted seed potato — or cured cut piece — in the trench:

• Sprouts facing up
• 10 cm (4 in) below the soil surface (measure from the top of the seed piece to the final soil level after covering)
• 30 cm (12 in) apart along the row

Cover the seed pieces with soil and firm gently. Do not compact heavily — potatoes need loose soil for the developing tubers to expand into.

Why 30 cm (12 in) spacing matters: Each potato plant can spread its root system and tuber zone out to about 30 cm (12 in) in every direction. Planting closer packs the plants so tightly that tuber development is inhibited, blight spreads faster via the canopy, and individual yields drop. Wider spacing (up to 38 cm / 15 in) is fine for main-crop varieties; first earlies can sit at the closer end of the range.

Container planting: In a grow bag or container at least 40 cm (16 in) deep, add 10–15 cm (4–6 in) of potting mix, place 1–2 seed pieces on top, cover with 10 cm (4 in) of mix, and then add more mix in stages as stems emerge — the container equivalent of hilling.

Step 6: Hill the plants as they grow

Hilling is the most important ongoing task in potato growing. Once the green stems push 15–20 cm (6–8 in) above the soil surface, mound loose soil or compost up around each stem cluster, leaving only the top 5–8 cm (2–3 in) of foliage exposed above the hill.

Repeat every 10–14 days for as long as the plants are actively growing — usually three to four hilling sessions per crop.

Why hilling is non-negotiable:

1. More tubers. New tubers form along the buried portion of the stem above the seed piece. Every extra centimetre of buried stem is potential yield.
2. Prevents greening. Tubers that poke above soil level turn green and produce solanine, making them bitter and mildly toxic. Hilling keeps them covered and dark.
3. Weed suppression. The mounded soil smothers most weed seedlings around the base of the plants.

In containers, the same principle applies: keep adding potting mix around the stems as they grow, stopping 5 cm (2 in) from the rim.

Row planting vs container planting — comparison

Factor	Row / bed planting	Container / grow bag
Yield per plant	Higher — room to spread	Lower — limited volume
Space needed	60–75 cm (24–30 in) between rows	Single container on balcony/patio
Ease of harvest	Dig with fork, can miss tubers	Tip container, near-total recovery
Hilling method	Mound soil along rows	Add potting mix to container
Watering	Relies more on rain + manual	Dries out faster — check daily in heat
Best varieties	Main-crop, high-yield	First earlies, compact varieties

Watering after planting

Potatoes have three critical watering windows:

1. At planting: Water gently to settle the soil around the seed pieces. Don’t saturate — just moisten.
2. During tuber initiation (when plants flower): This is the most water-critical phase. Dry soil at this point directly reduces tuber size. Aim for 2–3 cm (0.75–1 in) of water per week from rainfall plus supplemental watering.
3. Before harvest: Stop watering 10–14 days before you plan to dig. Dry soil at the end of the season firms the skins, reducing bruising and improving storage life.

Avoid wetting the foliage when watering — damp leaves encourage blight. Water at the base of the plant with a watering wand or drip irrigation.

Harvest timing

New potatoes (first earlies, 60–70 days): Harvest when the plants are in flower. Carefully open the side of the hill with your hands and feel for tubers. Take what you need and re-cover — the plant keeps producing. New potatoes have thin skins and are best eaten within a few days.

Main crop (90–100 days): Wait until the foliage naturally yellows, flops, and begins dying back on its own. That dieback is the signal that the plant has finished. Stop watering for 10–14 days. On a dry day, insert a fork 30 cm (12 in) from the base of each plant and lever upward — work from the outside inward to avoid spearing tubers.

Curing after harvest: Spread the harvested potatoes in a single layer in a warm (15–20°C / 59–68°F), dark, well-ventilated space for 1–2 weeks. Curing heals minor skin damage and thickens the skin for storage. Then move to a cool (4–10°C / 40–50°F), dark, dry location. Never store in the fridge — cold converts starch to sugar.

Common mistakes to avoid

• Not chitting. Unchitted seed potatoes emerge 10–14 days later and establish more slowly. In short seasons that delay can cost you a significant portion of the crop.
• Skipping the cure after cutting. Uncured cut pieces rot in damp soil before they sprout. The 24–48 hour wait is not optional.
• Planting too shallow. 10 cm (4 in) is the minimum starting depth. Shallow seed pieces produce fewer tubers and more surface tubers that green in sunlight.
• Skipping hilling. Without hilling, yield can drop by 30–50% compared to a properly hilled plot. There is no substitute.
• Planting in the same bed year after year. Soil-borne diseases build up fast. Rotate potato crops to a different bed at least every 3 years.
• Watering overhead. Wet foliage speeds the spread of late blight. Water at the base.
• Harvesting in wet soil. Wet-soil harvest = thin-skinned, bruised potatoes that rot in storage. Wait for a dry day and dry soil.

Troubleshooting

Symptom	Likely cause	Fix
No emergence after 4 weeks	Seed pieces rotted, planted too deep in waterlogged soil	Check drainage; replant cured pieces in drier bed
Pale, weak stems at emergence	Unchitted stock, very cool soil	Be patient; soil temp below 10°C (50°F) slows emergence significantly
Yellow leaves before 70 days	Underwatering, nitrogen deficiency, or early blight	Deep water once; if brown ringed spots appear, remove affected leaves and treat as blight
Scabby rough patches on skins	Alkaline soil or fresh manure	Lower pH to 5.5–6.5; don’t add fresh manure; rotate bed
Green-tinged tubers	Tubers exposed to light	Hill more aggressively; check container fill level
Tiny tubers even on healthy plants	Too shallow, no hilling, nitrogen overload	Next season: deeper planting, consistent hilling, switch to lower-nitrogen fertilizer
Brown spots inside tubers (hollow heart)	Uneven watering during growth spurt	Maintain consistent 2–3 cm (0.75–1 in)/week; avoid feast-or-famine irrigation
White fungal growth on leaves, blackening stems	Late blight	Remove and bag (never compost) all infected material immediately; harvest what you can; don’t replant potatoes in that bed for 3 years

Watch: planting seed potatoes video guide

This video pairs well with the steps above and gives a visual walkthrough of chitting, cutting, trench preparation, and hilling that’s hard to convey in words alone.

Related reading

• How to plant sprouted potatoes — using kitchen-sprouted spuds instead of certified seed stock, with the same depth and hilling rules.
• How to plant potatoes in a bucket — the full container method if you only have a balcony or patio.
• How to plant sweet potato slips — a completely different planting method for the tropical relative of the common potato.
• Use the free Tazart plant care app to set watering reminders and hilling alerts timed to your specific planting date — it adjusts for your local weather automatically.

A note on conditions

Potato performance varies with soil type, variety, climate, container size, and local weather. The depths, spacings, and timings in this guide are proven starting points — treat them as a baseline, then adjust based on what you observe. A potato plant growing in sandy loam in a warm climate will behave differently from the same variety growing in clay-amended raised beds in a cool, wet region. Both can produce excellent crops once you understand what your specific conditions need.