sweet potatoIpomoea batatas

sweet potato

sweet potatoes

1. Ipomoea batatas

1. Ipomoea batatas

1. sweet potato

morning glory

1. tuber
2. leaves
3. shoots

Sweet potato (Ipomoea batatas) is a heat-loving root vegetable from the morning glory family. It is prized for its sweet-tasting tubers, which are rich in vitamins and fiber.

Sweet potato originated in Central and South America and was cultivated by indigenous peoples over 5000 years ago. It reached Europe via Spain and Portugal and is now grown worldwide in tropical and subtropical regions.

1. Taskcheck_storage

   Label

   Storage check

   Prioritymedium

   Months

   1. 1

   Estimated effortlow

   Notes

   Check overwintered tubers for rot, discard affected ones immediately

1. Taskstart_preculture

   Label

   Start pre‑culture

   Priorityhigh

   Months

   1. 2

   Estimated effortmedium

   Notes

   Sprout tubers in moist sand or water at 20–25 °C until shoots appear

1. Taskpot_slips

   Label

   Pot slips

   Priorityhigh

   Months

   1. 3

   Estimated effortmedium

   Notes

   Once shoots are about 10 cm long, cut them off and pot up

1. Taskharden_off

   Label

   Harden off

   Prioritymedium

   Months

   1. 4

   Estimated effortlow

   Notes

   Place young plants outdoors in a sheltered spot during the day, bring in at night

1. Taskplant_out

   Label

   Plant out

   Priorityhigh

   Months

   1. 5
   2. 6

   ConditionBoden mindestens 15 °C, keine Frostgefahr

   Estimated effortmedium

   Notes

   From mid‑May plant on ridges or in beds; spacing 30–40 cm, row spacing 70–100 cm

1. Taskwater_regularly

   Label

   Water regularly

   Priorityhigh

   Months

   1. 6
   2. 7
   3. 8

   Estimated effortmedium

   Notes

   Maintain even moisture, avoid waterlogging

1. Taskweed_and_feed

   Label

   Weed and fertilise

   Prioritymedium

   Months

   1. 7

   Estimated effortmedium

   Notes

   Hoe regularly, feed with nettle tea if growth is weak

1. Taskstop_nitrogen

   Label

   Stop nitrogen fertilisation

   Prioritymedium

   Months

   1. 8

   Estimated effortlow

   Notes

   From August stop applying nitrogen to encourage tuber development

1. Taskprepare_harvest

   Label

   Prepare harvest

   Priorityhigh

   Months

   1. 9

   Estimated effortlow

   Notes

   Start harvesting when leaves turn yellow

1. Taskfinal_harvest

   Label

   Final harvest and curing

   Priorityhigh

   Months

   1. 10

   ConditionVor dem ersten Frost

   Estimated efforthigh

   Notes

   Dig tubers before frost, cure for one week at 25–30 °C and high humidity

1. Taskstore_tubers

   Label

   Store tubers

   Priorityhigh

   Months

   1. 11

   Estimated effortmedium

   Notes

   Store in the dark at 12–15 °C and 80–90 % humidity

1. Taskstorage_check

   Label

   Storage check

   Prioritymedium

   Months

   1. 12

   Estimated effortlow

   Notes

   Monthly check for rot and mould, remove affected tubers

Full sun

sheltered from wind preferred

warm, protected location e.g. against a south‑facing wall or in a cold frame

loose, sandy loam

very well‑drained

Deeply loosen, remove stones, incorporate well‑rotted compost; ridges of 30 cm height are recommended

Avoid heavy, compacted soils; in clay soils raised beds or ridge cultivation are beneficial

drip irrigation or low‑level watering

regularly, especially during dry spells 2–3 times per week

approx. 20–30 mm per week

1. tuber initiation (July)
2. tuber bulking (August/September)

Avoid wetting the foliage as this encourages fungal diseases; mulch helps retain moisture

Incorporate 3–4 l/m² of well‑rotted compost before planting

During growth: apply potassium‑rich fertiliser (e.g. patentkali or wood ash); moderate nitrogen if needed

Excessive nitrogen fertilisation (promotes foliage at the expense of tubers)

Potassium is the most important nutrient for tuber formation; phosphorus supports root growth

Sweet potato needs a long, warm growing season; only one planting per season. Crop rotation: good after legumes or brassicas; do not grow after other Convolvulaceae or potatoes

1. Legumes (peas, beans)
2. Brassicas
3. Cereals
4. Green manure

Do not grow sweet potatoes on the same plot as the previous year; maintain a minimum 4-year rotation to avoid soilborne diseases such as Fusarium wilt.

1. Soil pests (wireworms)
2. Sucking insects (aphids, spider mites)

1. Soilborne fungal diseases (Fusarium, black rot)
2. Leaf fungi (powdery mildew)

1. Use healthy planting material
2. Maintain crop rotation and spacing
3. Ensure even watering
4. Enrich soil with organic matter

For wilting symptoms, first check soil moisture; for tuber discolouration, inspect for wireworm entry holes.

1. Slugfusarium-welke-profil

   Severityhigh

   Conditions

   1. Moist, heavy soil
   2. Rotation with host plants

   Affected parts

   1. leaves
   2. stems
   3. tubers

   Prevention

   1. Follow crop rotation
   2. Use disease-free planting material

   Organic control

   1. Mycorrhizal preparations
   2. Compost applications
2. Slugschwarzfaeule-profil

   Severityhigh

   Conditions

   1. Injuries during harvest or storage
   2. High storage humidity

   Affected parts

   1. tubers

   Prevention

   1. Gentle harvest
   2. Optimise storage conditions

   Organic control

   1. Remove affected tubers immediately
   2. Disinfect storage
3. Slugechter-mehltau-profil

   Severitymedium

   Conditions

   1. High humidity
   2. Moderate temperatures 15–25°C

   Affected parts

   1. leaves

   Prevention

   1. Avoid wet leaves
   2. Maintain spacing

   Organic control

   1. Sulfur preparations
   2. Baking soda solution

1. Symptom

   Wilting and yellowing of leaves

   Possible causes

   1. Fusarium-Welke
   2. Wassermangel
   3. Staunässe

   First checks

   1. Check soil moisture
   2. Examine stem base for discolouration
2. Symptom

   Dark, sunken spots on tubers

   Possible causes

   1. Schwarzfäule
   2. Drahtwurmfraß

   First checks

   1. Check tubers for entry holes
   2. Detect rot odour
3. Symptom

   White powdery coating on leaves

   Possible causes

   1. Echter Mehltau

   First checks

   1. Wipe coating with finger – fungal powder wipes off

Systematic inspection from top to bottom: leaves, stems, soil surface, tubers.

1. germination
2. leaf development
3. tuber initiation
4. tuber bulking
5. harvest maturity

In Central Europe the growing period from planting slips (May/June) to harvest (September/October) lasts about 90–150 days, strongly variety dependent.

Flowers funnel-shaped, pink to purple, appear under short-day conditions; in Central Europe often sparse or absent.

Once per season; individual tubers can be taken in late summer if desired.

1. Leaves yellow and wilt
2. Tubers flex and crack when levered

Do not wash tubers, only brush off dry soil. Then cure for one week at 25–30 °C and high humidity to toughen the skin and heal wounds.

Cool, dark space with high humidity

3–6 months under optimal conditions

1. Freezing (blanched)
2. Drying (chips or powder)
3. Pickling (e.g. in brine or vinegar)
4. Purée and freeze

1. tuber
2. leaves
3. young shoots

1. seeds (contain small amounts of toxic alkaloids)
2. raw tubers in very large quantities (may cause flatulence)

The tubers are not toxic raw for humans but can be hard to digest. The seeds contain indole alkaloids and should not be consumed.

Edible raw in small amounts, but starchy and hard on the stomach; much more digestible when cooked.

Not applicable as seed set is generally absent. For breeding purposes, controlled pollination is done in greenhouses or in tropical regions.

Not relevant.

Not relevant.

Sweet potato is an herbaceous, non-woody perennial. Woody pruning and grafting are not applicable.

Flowers are occasionally visited by bees, but are of minor importance for biodiversity in Central Europe.