Smallanthus sonchifolius

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earth apple

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earth apple RHS
earth apple RHS

Other common names

yacon

Synonyms

Polymnia sonchifolia

Herbaceous Perennial
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A rhizomatous perennial usually grown as an annual to provide an edible crop of tuberous roots which are mildly sweet, crisp and juicy. Large, triangular leaves are borne on stems up to 1.5m tall and small, yellow, daisy-like flowers are borne from late summer into early autumn

Position

Full sun

Soil Types

Clay, Loam, Sand

Max Height

1-1.5 metres

Max Spread

0.5-1 metres

Size

Time to Maturity
1–2 years
Max Spread
0.5-1 metres
Max Height
1-1.5 metres

Growing Conditions

Clay Loam Sand
Moisture
Moist but well–drained
pH
Acid or Alkaline or Neutral

Position

Full sun
Aspect
South–facing or West–facing or East–facing
Exposure
Sheltered
Hardiness

Hardiness Ratings

All ratings refer to the UK growing conditions unless otherwise stated. Minimum temperature ranges (in degrees C) are shown in brackets

  • H1A: under glass all year (>15C)
  • H1B: can be grown outside in the summer (10 - 15)
  • H1C: can be grown outside in the summer (5 - 10)
  • H2: tolerant of low temperatures, but not surviving being frozen (1 to 5)
  • H3: hardy in coastal and relatively mild parts of the UK (-5 to 1)
  • H4: hardy through most of the UK (-10 to -5)
  • H5: hardy in most places throughout the UK even in severe winters (-15 to -10)
  • H6: hardy in all of UK and northern Europe (-20 to -15)
  • H7: hardy in the severest European continental climates (< -20)
H4

Colour & Scent

Season Stem Flower Foliage Fruit
Spring
Summer
Autumn
Winter

Botanical Details

Family
Asteraceae
Native to GB/Ireland
No
Foliage
Deciduous
Habit
Clump forming
Genus
A genus of rhizomatous flowering perennials, native to South America, with bushy green foliage and daisy-like yellow flowers. Some cultivars are grown as vegetables, with the potato-like tubers tasting similar to a pear with a texture like water chestnuts
Name Status
Correct

How to Grow

Cultivation

Grows best in a fertile, moist but well drained soil in full sun with shelter from strong winds to prevent damage to the leaves. Plant outside only when the risk of frost has passed.

Propagation

Propagate by seed, by cuttings or by division of rhizomes

Pruning

No pruning required

Pests

Slugs and snails may be troublesome

Diseases

May be susceptible to cucumber mosaic virus and powdery mildews