garden asparagus

Asparagus officinalis
infestation in a wetland area in Sydney (Photo: Sheldon Navie)
habit (Photo: Sheldon Navie)
habit in fruit (Photo: Jackie Miles and Max Campbell)
close-up of flowers (Photo: Sheldon Navie)
close-up of immature fruit (Photo: Sheldon Navie)
mature fruit (Photo: Jackie Miles and Max Campbell)
close-up of seeds (Photo: Jose Hernandez at USDA PLANTS Database)
Vine
Whorled
Reduced / Needle
White
Yellow
Green

A long-lived herbaceous plant that produces short-lived upright stems 0.5-1.5 m tall each year. Its green stems are densely branched towards their tips and do not have any thorns. Its needle-like 'leaves' (10-32 mm long and 0.5-1 mm wide) are borne in clusters of 3-15. Its greenish-white to yellowish flowers (3-8 mm long) are arranged singly or in pairs along the branches. Separate male and female flowers are often borne on separate plants. Its rounded berries (5-10 mm across) turn red as they mature and contain 2-6 seeds.

Common names 
Also known as: garden asparagus, edible asparagus, florist's fern, green asparagus, white asparagus, wild asparagus,
Family 
Asparagaceae
Deciduous 
No
Flowering time 
Spring - Summer
Native/Exotic 
Exotic
Origin 
Native to northern Africa, Europe, western Asia.
Notifiable 
No
Council declaration 
SIL – Special Investigation List
Known distribution 

This species is occasionally naturalised in southern and eastern Australia (i.e. in south-eastern Queensland, eastern New South Wales, ACT, Victoria, Tasmania, south-eastern South Australia and south-western Western Australia).

Habitat 

A weed of wetlands, riparian vegetation, open woodlands, coastal environs, roadsides, railways, disturbed sites, waste areas and old gardens.

Habit 

A long-lived (i.e. perennial) herbaceous plant that has a crown and produces short-lived (i.e. annual) stems each year. These upright (i.e. erect) stems usually grow 0.5-1.5 m tall, but may occasionally reach up to 2.5 m in height.

Impact and control methods 

"This commonly grown vegetable plant has spread from cultivation and is a minor environmental weed in the cooler parts of south-eastern Queensland. It is primarily found in wetlands, watercourses (i.e. riparian areas) and open woodlands in the cooler parts of the region (e.g. in the Stanthorpe area).

Garden asparagus (Asparagus officinalis) is more common in southern Australia. It is regarded as an environmental weed in Victoria and as a minor or potential environmental weed in New South Wales, the ACT, South Australia and Western Australia. It is present in conservation areas in some of these states, and infestations in some areas have become more apparent in recent years (e.g. in the Adelaide and Mount Lofty Ranges region in South Australia)."

Stem and leaves 

"The stems are green and hairless (i.e. glabrous) and are densely branched towards their tips. The smaller branches are very slender and upright or spreading (i.e. ascending to perpendicular). They do not have thorns, but do have scale-like bracts.

The leaves are reduced to tiny scales (3-4 mm long) and what appear to be the 'leaves' are actually small stem segments which function as leaves (i.e. cladodes). Several (3-15) of these needle-like (i.e. filiform) 'leaves' (10-32 mm long and 0.5-1 mm wide) are produced in a cluster above each scale leaf. They are hairless (i.e. glabrous), either straight or slightly curved, and have pointed tips (i.e. acute apices)."

Flowers and fruits 

"The bell-shaped (i.e. campanulate) flowers are arranged singly or in pairs in the forks (i.e. axils) of the scale leaves. They are borne on stalks (i.e. pedicels) 6-15 mm long that are jointed at or above the middle. These flowers have six greenish-white to yellowish 'petals' (i.e. tepals or perianth segments) that are fused together at the base (3-8 mm long and 1-2 mm wide). Separate male and female (i.e. unisexual) flowers are often borne on separate plants, but sometimes the flowers have both male and female parts (i.e. they are occasionally bisexual). The male and bisexual flowers have six yellow stamens, while the female and bisexual flowers have an ovary topped with a short style and stigma. Flowering occurs during spring and summer.

The fruit is a rounded (i.e. globose) berry that turns from green to red as it matures. These fruit (5-10 mm across) contain 2-6 seeds. Fruit are present during autumn and early winter."

Reproduction and dispersal 

"This species reproduces by seed and also vegetatively via creeping underground stems (i.e. rhizomes).

The berries are readily eaten and dispersed by fruit-eating (i.e. frugivorous) birds and other animals. Seeds and rhizomes may also be spread in dumped garden waste."

Similar species 

"Garden asparagus (Asparagus officinalis) is very similar to asparagus fern (Asparagus virgatus ) and relatively similar to ground asparagus fern ( Asparagus aethiopicus 'Sprengeri'), the climbing asparagus ferns (Asparagus africanus and Asparagus plumosus ), bridal creeper (Asparagus asparagoides ), sicklethorn (Asparagus falcatus ) and ming asparagus fern (Aspargaus retrofractus). These species can be distinguished by the following differences:

■garden asparagus (Asparagus officinalis) is an upright plant (up to 2 m tall) with short-lived thornless stems that die back each summer. Its 'leaves' (i.e. cladodes) are borne in groups of one to five along the stems, are linear in shape, and are relatively small (12-25 mm long and 0.5 mm wide). Its flowers are borne singly or in pairs and its fruit turn red when mature.

■asparagus fern (Asparagus virgatus ) is an upright plant (up to 1.5 m tall) with short-lived or long-lived thornless stems. Its 'leaves' (i.e. cladodes) are borne in groups of three along the stems, are linear in shape, and are relatively small (6-20 mm long and 0.5-1 mm wide). Its flowers are borne singly and its fruit turn orange when mature.

■ground asparagus fern ( Asparagus aethiopicus 'Sprengeri') is usually a low-growing or scrambling plant with spreading or drooping branches bearing some small sharp thorns. Its 'leaves' (i.e. cladodes) are borne in groups of one to eight (usually 2-5) along the stems, are linear in shape, and are moderately large (15-25 mm long and 2-3 mm wide). Its flowers are borne in elongated, many-flowered clusters (i.e. racemes) and its fruit turn red when mature.

■climbing asparagus fern (Asparagus africanus ) is a climbing plant with long-lived and thorny main stems. Its 'leaves' (i.e. cladodes) are borne in groups of more than three along the stems, are linear in shape, and are relatively small (6-15 mm long and only about 0.5 mm wide). Its flowers are borne in small several-flowered clusters and its fruit turn orange when mature.

■climbing asparagus fern (Asparagus plumosus ) is a climbing plant with long-lived and thornless or slightly thorny main stems. Its 'leaves' (i.e. cladodes) are borne in groups of more than three along the stems, are linear in shape, and are very small (4-7 mm long and only about 0.5 mm wide). Its flowers are borne singly or in pairs and its fruit turn black when mature.

■bridal creeper (Asparagus asparagoides ) is a creeping or climbing plant with short-lived thornless stems that die back each summer. Its 'leaves' (i.e. cladodes) are borne singly along the stems, are oval (i.e. elliptic) in shape, and are relatively large (10-70 mm long and 10-30 mm wide). Its flowers are borne singly or in few-flowered clusters and its fruit turn red when mature.

■sicklethorn (Asparagus falcatus ) is a shrubby climbing plant with long-lived and thorny main stems. Its 'leaves' (i.e. cladodes) are borne in groups of three to six along the stems, are elongated in shape, and are quite large (35-125 mm long and 2-5 mm wide). Its flowers are borne in elongated, many-flowered clusters (i.e. racemes) and its fruit turn red or whitish when mature.

■ming asparagus fern (Aspargaus retrofractus) is shrubby plant with somewhat woody branches bearing some small sharp thorns. Its 'leaves' (i.e. cladodes) are borne in large clusters along the stems, are linear in shape, and are moderately large (8.5-25 mm long and only about 0.5 mm wide). Its flowers are borne in large rounded clusters and its fruit turn black when mature."