Edible roots
Photos and story by Russ Grayson
Root crops are a concentrated source of dietary carbohydrates and proteins. They are among humanity’s oldest crops.
Edible roots are suitable in community gardens in:
- shared gardening space for root crops which grow as spreading crops
- larger allotments of a size to cope with spreading crops
- smaller allotments in which root crops with a shrub growth form, such as potato, can be grown.
Root crops come in both annual and perennial forms (perennials are those taking longer than two years to produce a crop).
For community gardeners, the root crops offer:
- a concentrated source of nutritional, carbohydrate-rich ‘energy food’
- a source of botanical interest where the less common species are grown
- a way to make use of unused garden space.
Source:
Some of these root crops are difficult to find in nurseries. In Australia, you may be able to mail order them from:
Green Harvest
https://www.greenharvest.com.au/
Ask for their catalog. Some crops are available only at particular times of the year.
Design
- annual root crops can be planted in the annual garden bed or allotment, depending on size
- root crops form one of the components of a crop rotation system with leaf, fruiting and leguminous crops
- in the southern hemisphere, locate the annual vegetable garden on the northern (sunward) side so as to maximise exposure to sunlight.
To keep your root crops healthy:
- protect them from strong and cold winds
provide plenty of water but do not over-water
monitor them for plant diseases and insect pests
maintain soil fertility by adding compost and mulch.
Notes on the plant description
- growth form: sizes given are for mature plants and are approximate only – the size a plant will grow to depends on microclimate, watering, soil fertility and the incidence of insects pests and plant diseases
- botanic name: these are the names botanists and horticulturists use to identify plants; sometimes, a single plant will have more than one common name, leading to difficulty in identifying it; there is only one botanic name so it is a more reliable way to identify a plant.
- spp: abbreviation for ‘species’ which denotes a particular plant variety
- family: a larger grouping of plants, all with some characteristic in common, into which plants are classified
- propagation: how plants are started
- vegetative reproduction is started from a cutting or a sprouting root such as a rhizome or tuber.
Centre of diversity: the region where the plant originated and from where it spread.
CARROT
Botanic name: Daucus carota
Family: Apiaceae
Growth form: tapering tuber of variable length depending on variety.
Biennial:
- the plant produces the tuber in its first year
- flowers and produces seed in the second year
- orange or yellow coloured tuber.
Edible part: tuber eaten raw or cooked.
Cultivation:
There are many varieties of carrot, varying in size and colouration.
- from seed
- new plants can be sprouted by cutting of top of tuber and waiting until it sprouts, then planting.
Centre of diversity:
- probably eastern Mediterranean
- grown in imperial Rome and ancient Turkey
- yellow and purple varieties grown in Europe until the seventeenth century when the orange carrot was developed in Holland.
CHINESE ARTICHOKE
Botanic name: Stachys affinis
Family: Labiatae
Growth form:
- annual
- stiff stem to around a metre grows from tuber.
Edible part: tuber.
Cultivation:
- propagated vegetatively from tuber
- planted in winter in warm temperate climates.
Centre of diversity: China, recorded in Europe in 1882.
DAIKON and other radishes
Daikon is a member of the diverse radish group of plants that vary in:
- shape — cylindrical to spherical
- size — from as small as approximately two centimetres diameter
- colour — white, red, black, purple, yellow – depending on variety
- growth period — from weeks to months.
Botanic name: Raphanus sativus (daikon)
Growth form (daikon): white root to around 30 centimetres long and 4 centimetres in diameter.
Edible part: tuber; edible raw or cooked.
Cultivation:
- daikon is a slower growing variety of radish maturing in warm temperate coastal regions of Easteern Australia in late autumn
- the size of the tuber yields plenty of food
- plant smaller fast-growing radish varieties successionally every two weeks.
Propagation: from seed.
Use in garden: plant as catch crop between slower growing vegetables to make use of garden space until slower growing plants fully occupy the space.
Centre of diversity:
- Asia
- recorded in use in Egypt from 2980BP (before present)
- ancient crop in Japan.
GALANGAL
Varieties: greater galangal; lesser galangal.
Botanic name:Languas galanga
Family: Ziniberaceae; same family as ginger.
Growth form:
- similar to ginger
- leaves grow from stiff stem
- knobbly rhizomes grow in soil.
Edible part: rhizome
- can be dried or grated fresh
- used in curry and satay sauce
- used as spice to flavour food.
Cultivation: vegetative – sprouting rhizome planted.
Centre of diversity:
- South East Asia, southern China
- occurs wild in jungle clearings and is also cultivated.
GARLIC
Botanic name: Allium sativum
Growth form:
- similar in appearance to onion
- bulb enclosed in a papery, whitish/ purplish skin.
Edible part:
- bulb
- used as food flavour
- medicinal uses
Cultivation:
- sprouting clove planted
- provide warm microcllimate.
Centre of diversity:
- Central Asia, China
- in use since ancient times in India, Egypt, China.
GINGER
Botanic name: Zingiber officinale
Family: Ziniberaceae
Growth form:
- long, narrow leaves grow from stiff stem
- rhizomes (the root structure) form underground cluster
- grows to approximately one metre in height.
Edible part:
- knobbly rhizome used as spice to flavour food
- rhizome can be dried and grated
- eaten raw or used in cooking
- used as a tea
- medicinal uses.
Cultivation:
Ginger is a tropical/ subtropical perennial.
- shade tolerant
- prefers a hot, frost-free environment
- grows in a large container.
Propagation:
- vegetative — sprouting rhizome planted
- prefers moist, well-drained soil.
Centre of diversity: South East Asia.
JERUSALUM ARTICHOKE
Botanic name: Helianthus tuberous
Family: Compositae; same family as sunflower and yacon.
Growth form:
- similar to sunflower
- tall, single stem to around a metre in height, sometimes more, with wide, soft laves
- yellow flowers like, but smaller than, sunflower
- produces cluster of rhizomes in late autumn/ early winter in warm temperate coastal climates of Eastern Australia.
Edible part: rhizome
- cooked as vegetable
- used in soup
- edible raw.
Cultivation:
- frost hardy
- tolerates a variety of soils
- rhizomes ready to harvest when foliage dies
- rhizomes may be stored in soil for limited period
- high productivity in good conditions.
Propagation: vegetative; from rhizome.
Centre of diversity:
- North America
- cultivated and collected from wild by Indian peoples.
OCA
Also known as: New Zealand yam; cuiba (Venezeula); iribia (Columbia)
Botanic name: Oxalis tuberosa
Family: Oxalidaceae
Growth form:
- low-growing annual bush
- forms clusters of red tubers to 10cm long
Edible part: tubers eaten after cooking.
Cultivation:
- as for potato
- fertile soil, regular watering.
Propagation: from tuber.
Centre of diversity:
- Andeas region of South Ameica
- staple crop of Lake Titicaca region of Bolivia
- introduced into New Zealand from Chile in 1869 where it is now known as ‘New Zealand yam’.
ONION
Botanic name: Allium sepa
Family: Alliaceae
Growth form:
- annual bulb
- colour variable with variety — white, red (used raw in salads), brown, purple
- shape variable — spherical, oval, elongated.
Edible part: bulb; eaten raw or cooked.
Cultivation:
- from seed
- plant in sunny, well-drained position.
Centre of diversity:
- probably Central Asia
- cultivated by ancient Egyptians at least as far back as 3400BP (before present).
PARSNIP
Botanic name: Pastinaca sativa
Family: Apiaceae
Growth form: Parsnip is biennial; the plant produces the tuber in its first year, then flowers and produces seed in the second.
- tapering tuber
- white colouration
- there area number of varieties of parsnip that vary in size.
Edible part: tuber — eaten cooked.
Cultivation: from seed new plants can be sprouted by cutting of top of tuber, waiting until it sprouts, then planting
Centre of diversity:
- Mediterranean region
- grown by ancient Roman and Greek civilisations.
POTATO
Botanic name: Solanum tuberosum
Family: Solanaceae (tomato family)
Growth form: small annual shrub.
Edible part: tuber— boiled, fried, roasted, steamed.
Cultivation:
- there are numerous varieties of potato
- high productivity achievable in good growing conditions
- plant in well drained soil.
Propagation:
- vegetative — from sprouting tuber
- from seed potato from a nursery.
Insect pests: scab; viruses; aphids; slugs
Diseases: potato blight.
Centre of diversity:
- Central and South America
- potato is an ancient crop of Indian cultures
- recorded in Europe for the first time in the 1560s.
SWEET POTATO
Another common name: kumara (Polynesia).
Botanic name: Ipomoea batatas
Growth form:
- perennial
- scrambling vine
- heart shaped or lobed leaves
- flesh colour of tuber variable – whitish, purplish, yellow.
Edible part:
- tuber — boiled, fried, roasted, steamed
- tips of young shoots cooked.
Cultivation:
- prefers warm conditions
- tolerates light shade
- plant as a ground cover in the orchard
- use as perennial living mulch in orchard or elsewhere.
Propagation:
- sprouting tuber planted
- from tip cuttings
Centre of diversity:
- South America
- cultivated for thousands of years in South East Asia, Pacific Islands and New Zealand.
TARO
Also known as:
• cocoyam
• dasheen
• edo
• elephant’s ear.
Botanic name: Alocasia esculanta
Family: Araceae
Growth form:
- large, pointed, broad leaves grow from tuber on stiff stems
- grows to around one metre in height depending on type.
Edible part:
- large round or elongated tuber
- leaf
- tuber can be made into flour.
Caution:
- do not eat any part of the taro plant raw
- cook all parts well to destroy irritating calcium oxylate crystals
- Joy Larkom (Oriental Vegetables, 1991, John Murray, London) says when cooking the young taro leaf to boil twice, discarding the water to remove the acrid flavour.
Cultivation:
- grows in wet tropical/subtropical/warm temperate climates
- prefers moist soil
- tolerates medium shade or grows in full sun
- will grow in mud
- grows in shallow water
- grown ‘wet’ in paddies in Asia or ‘dry’ in soil.
Propagation:
- by planting the sprouting tuber
- cut off top of tuber with shoot then plant.
Centre of diversity:
- probably India
- found throughout the wet tropics — South East Asia, Pacific Islands, PNG, China
- an ancient crop in use for at least 7000 years.
TUMERIC
Botanic name: Carcuma domestica
Family: Ziniberaceae; same family as ginger.
Growth form:
- similar to ginger
- leaves grow from stiff stem
- elongated rhizomes in soil.
Edible part: rhizome used as spice to flavour food; dried or grated.
Cultivation/propagation: vegetative — sprouting rhizome planted.
Centre of diversity: South East Asia.
YACON/ PERUVIAN GROUND APPLE
Botanic name: Polymnia sonchifolia
Family: Compositae
Growth form:
- an annual to 2 metres resembling the sunflower
- soft, heart-shaped leaves along a stiff stem
- a cluster of underground tubers is formed; moist flesh is off-whote to pale brown in colour
Edible part: tuber eaten raw or cooked
Cultivation: high productivity in good growing conditions.
Propagation: vegetative – from the tuber.
Centre of diversity: Peru — grown by Incas.
YAM
Botanic name: Dioscoria spp
Growth form:
- scrambling vine of variable length
- heart-shaped leaves
- tuber size varies with species.
Edible part: tuber; cooked.
Cultivation: can be used as a trellis crop or left to scramble over the ground.
Propagation:
- by sprouting tuber
- from tip cuttings.
Centre of diversity:
Asia — an ancient crop collected in the past as wild harvest and now cultivated
Australia — varieties collected by Aboriginies as wild harvest.
