Blackberry (Rubus fruticosus species aggregate)

Also known as: black berry, blackberries, black berries

Blackberries are semi-deciduous, scrambling shrubs with prickly stems. Recognised as one of the worst weeds in Australia, blackberries are a Weed of National Significance.

Profile

How does this weed affect you?

Recognised as one of the worst weeds in Australia, blackberry was declared a Weed of National Significance in 1999. Blackberries belong to a large genus (group of species) called Rubus which includes other berry plants such as raspberries (R. idaeus), dewberries (R. roribaccus), and loganberries (R. loganobaccus).

The Rubus fruiticosus aggregate 

In NSW the group of blackberries that pose a weed risk are referred to as the Rubus fruticosus aggregate (R. fruticosus agg.) or, commonly, as European blackberries.

Currently there are 16 species in the R. fruticosus aggregate that occur in Australia, with the following nine species occurring in NSW:

  • R. anglocandicans
  • R. leucostachys
  • R. polyanthemus
  • R. laciniatus
  • R. ulmifolius var. ulmifolius
  • R. ulmifolius var. anoplothyrsus
  • R. vestitus
  • R. leightonii
  • R. phaeocarpus

There are a number of other introduced weedy Rubus species that are often referred to as blackberries but are not part of the Rubus fruiticosus species aggregate, including:

  • R. laudatus
  • R. philadelphicus
  • R. roribaccus (dewberry, youngberry, boysenberry)
  • R. loganobaccus (loganberry)
  • R. ellipticus (yellow Himalayan raspberry)
  • R. rugosus (keriberry)
  • R. niveus
  • R. idaeus (raspberry)

Furthermore, there are a number of native Rubus species in Australia that are not part of the R. fruiticosus aggregate with R. pavifolius growing most commonly in association with R. fruticosus agg. species.

The information presented here is specific to the R. fruticosus aggregate in NSW.

Blackberry grows vigorously and can infest large areas quickly. Negative impacts include:

  • reduced available grazing land (most livestock find blackberry unpalatable) and restricted livestock access to water (when growing densely around waterbodies)
  • reduced productivity of land caused by shading out of pastures and crops, and competition for soil moisture and nutrients
  • problems in forestry such as the prevention of regeneration of hardwood forests and reduced capacity of plantation softwood and hardwood seedlings to establish and grow. Thickets of blackberry also hinder access for forest operations
  • degradation of natural environments by displacing native plants and reducing habitat for native animals
  • devaluation of visual and recreational aspects of public land, parks and reserves
  • provision of harbour for vermin such as rabbits and foxes, and seasonal food for exotic animals such as starlings, blackbirds and foxes. These pest species also disperse blackberry seed, acting as vectors that spread blackberry infestations
  • increased fire hazard caused by dead blackberry material and obstruction of access to fire trails and water for controlling fires.

On the positive side, blackberry produces:

  • fruit (berries) which is favoured by many people and which can be eaten fresh, or used in cooking and preserves
  • blackberry flowers which produce nectar for bees to make honey
  • leaves that can be used to make herbal teas, medicinal products for chest ailments, and astringents for skin care
  • food and protection from predators for a number of native animals and birds, such as bandicoots and blue wrens.

Blackberry has been estimated to result in a loss of production and cost of control of between $95.1 million and $102.8 million in Australia. In comparison, the aggregated benefits of blackberry have been estimated to be approximately $1.5 million per annum, indicating that the negative impacts of blackberry vastly outweigh the positive impacts (CRC, 2006).

Where is it found?

Blackberry infests about 9 million hectares of land in Australia. The R. fruticosus agg. has probably reached its climatic limit of distribution; however, individual species in the aggregate may not have done so. The R. fruticosus agg. species in NSW currently occur in the following distribution:

  • R. anglocandicans – most common species occurring in all wetter areas of the state
  • R. leucostachys – widespread
  • R. polyanthemus – recorded in Kosciuzsko National Park
  • R. laciniatus – recorded in wetter areas of the state
  • R. ulmifolius var. ulmifolius – widespread
  • R. ulmifolius var. anoplothyrsus – possibly present in NSW
  • R. vestitus – recorded but not common
  • R. leightonii – recorded
  • R. phaeocarpus – Kowmung River area

How does it spread?

All blackberries can reproduce both vegetatively and by seed. The following describes these two methods of reproduction for the R. fruticosus agg.

Reproduction by seed

Apart from R. ulmifolius, the R. fruticosus agg. species are opomictic plants; that is, the plant’s embryo is stimulated but not fertilised by pollen, producing a clone. Where hybridisation occurs, one parent is likely to be the sexually reproducing R. ulmifolius. Each berry can contain from 20 to 30 seeds. At the end of the blackberry season, there may be up to 13,000 seeds/m2 under a blackberry bush. Plants in dense shade will produce fewer seeds than those in open areas. Seedling survival rate is also considerably lower in shaded areas compared to areas with full sun.

Vegetative reproduction

Where the tips of the primocanes touch the ground, roots may sprout in autumn and become new plants. These ‘daughter plants’ will then produce a primocane in the following spring. When the second year primocanes die, the daughter plant continues as an independent plant. R. fruticosus agg. species can also produce sucker plants and can reproduce from root fragments and other plant parts.

Birds, mammals (including foxes and humans), water and contaminated soil can all act as vectors for blackberry seeds, sometimes spreading them a long way from the mother plant.

What does it look like?

Blackberries are semi-deciduous, scrambling shrubs with tangled, prickly stems that form impenetrable thickets several metres high. Due to a large amount of variation between species, the best way to correctly identify a blackberry species is to send samples to a herbarium. The best time to collect samples for herbarium identification is when the plant is flowering. Include segments of both the primocane (first year cane) and the floricane (flowering cane). Keep one specimen for reference and send two to the herbarium. For more information on collecting samples see the Primefact Collecting and preparing plant specimens for identification and the Blackberry Control Manual, or contact your local weeds officer.

Root system

The root system is the perennial part of the plant. It comprises a woody crown that can grow up to 20 cm wide with a main root that can grow to a depth of 4 m. Secondary roots grow horizontally from the crown for 30-60 cm, then grow down and shoot thin roots in all directions.

Stems

Stems are known as canes and can grow up to 7 m long. They can be erect, semi-erect, arched or trailing. With the exception of R. ulmifolius var. anoplothyrsus, the canes are covered in sharp prickles. Canes generally live for two years (biennial) but may live for longer. They may be green, purplish or red depending on their exposure to light. The first year canes (primocanes) root where they touch the ground, producing a daughter plant. In their second year, primocanes form buds which sprout in spring to produce short canes (floricanes) that terminate in a branched cluster (panicle) of flowers and fruit.

Leaves

Leaves generally occur alternately along canes, are compound (with three to five leaflets), and are dark green on top with a lighter green underside. Leaflet veins and stalks are covered with short, curved prickles. Most leaves shed from the canes during winter except in warmer climates.

Flowers

White or pink flowers 2-3 cm in diameter occur at the end of floricanes from late November to late February. Clusters of flowers are either cylinder or pyramid-shaped, and may change colour between budding and opening depending on the species.

Habitat

Blackberry is is mostly restricted to areas with temperate climates (warm summers, cool winters) with an annual rainfall of at least 700 mm (regardless of altitude), but plants can grow in lower rainfall areas when other environmental conditions are favourable (such as along the banks of watercourses).

Acknowledgements

Author: Miriam Verbeek

Editors: Elissa van Oosterhout, Jill Read

References

Australian Government National Land and Water Resources Audit 2002-08 (2009). Gorrie, G. and Woods, B. (eds).

Bruzzese, E. and Lane, M. (1996). The Blackberry Management Handbook, Department of Conservation and Natural Resources, Victoria.

CRC for Australian Weed Management (2006). Economic Impact Assessment of Australian Weed Biological Control. Technical Series Report No. 10, AEC group, Cooperative Research Centre for Australian Weed Management, Adelaide.

NSW Department of Primary Industries Weed Management Unit (2009) Blackberry Control Manual: Management and control options for blackberry (Rubus spp.) in Australia. Department of Primary Industries, Victoria.

Other publications

back to top

Control

Detailed information about the control and management of blackberry is provided in the Blackberry Control Manual.

Maintaining control of blackberry is an ongoing process. It cannot be achieved with a one-off effort, especially with larger infestations. The best way to manage blackberry is to develop a plan that details the factors to be considered, the control methods to be used, and the monitoring and rehabilitation regimes to be implemented. Develop a management plan using the following steps:

  • Step 1 – Assess the problem (likely impacts of control methods; characteristics of infestation such as size, density, access); record the assessment on a topographic map; take photographs of the infestation.
  • Step 2 - Prioritise the areas for management; set up treatment zones (see Table 1 below); note where the infestation appears to have come from.
  • Step 3 – Develop the management plan; set a short term (first year), medium term (2-3 years) and long term (5 years) goal for each action; choose appropriate control methods; allocate financial resources and time for control as well as for follow-up and monitoring.
  • Step 4 - implement the plan monitor, record, re-treat, rehabilitate; keep records and review progress.
Table 1 – Treatment zones for prioritising blackberry control.
ZoneCharacteristicsActions
Exclusion zone Area free of blackberry Monitor and eradicate new plants
Eradication zone A few well-defined thickets Eradicate infestations
Monitor for new plants and eradicate
Containment zone A few large well-defined infestations with outlying thickets Start control where spread is most rapid
Work from outer edges in
Control to prevent reproduction
Protect high value assets
Protection zone Infestations widespread and scattered Control to reduce impacts and prevent spread

Physical control

Physical control alone is rarely successful because of the root structure of blackberry. These techniques are best used in combination with herbicides. The various methods of physical control are:

  • hand removal of top growth and digging up of roots - this method may be suitable for small and isolated infestations. Combining hand removal with cut stump herbicide application gives better results
  • mechanical grubbing and scalping - this method can be successful if the hoe or root rake completely removes the plant, including all roots
  • cultivation of the ground - because blackberry can reproduce vegetatively as well as sucker, cultivation can simply spread blackberry. However this method may be suitable if it is carried out frequently enough
  • using earthmoving equipment or slashing - this method is unlikely to remove root material and may even promote growth but can be useful to gain initial access to heavy infestations for further treatments.

Biological control

Biological control methods use natural enemies of blackberry to suppress and weaken plants. Currently the only deliberately released biological control agent in Australia is the leaf rust fungus Phragmidium violaceum. The fungus is only effective on the R. fruticosus agg., attacking the leaves and causing defoliation. It also infects flower buds and unripe fruit. The tips of infected canes die back, preventing the production of daughter plants. Overall the fungus reduces a plant’s ability to grow and reproduce. Phragmidium violaceum spores need dew, rain or high humidity to germinate. It is most effective when most of the plant’s canopy is young leaves, in areas where annual rainfall is greater than 750 mm and evenly spread over the year, and where January temperatures average about 20ºC.

There is currently an active program of releasing Phragmidium violaceum into new areas, as well as trialling other strains of fungus to specifically target other species of blackberry.

Grazing

Goats preferentially graze blackberry over improved pasture species. They may be useful as an initial control to reduce heavy infestations but follow-up treatment will be required after the goats are removed. The Meat & Livestock Australia publication Weed Control Using Goats: a guide to using goats for weed control in pastures provides useful information on the use of goats.

Cattle will not control blackberry infestations but will reduce tip rooting and the establishment of daughter plants.

Sheep graze blackberry seedlings depending on availability of other (more palatable) feed.

Pasture management

Pasture management or re-establishment can be an important component of a management program. Strong, actively growing pasture will help to prevent invasion from weeds.

Burning

Burning will not kill blackberry but it can be used to make infestations more accessible for follow-up treatment. Always allow sufficient regrowth before applying follow-up herbicide treatments.

Herbicides

Herbicides are the most reliable method for achieving local eradication of blackberry. For best results they should be used in combination with other control methods. A number of herbicides are registered for use on blackberry, each with advantages and disadvantages. Table 2 below briefly summarises some of these. 

Consider the following when selecting a herbicide for blackberry control:

  • proximity of the site to water – this affects the choice of registered herbicides
  • selectivity of the herbicide – it is usually best to retain desirable vegetation and groundcover where possible
  • cost of herbicides - at their highest application rates, the relative costs of the afore-mentioned herbicides from lowest to highest is: metsulfuron-methyl; triclopyr; picloram; glyphosate; picloram + triclopyr
  • level of control - experience has shown that a mixture of triclopyr + picloram used with or without aminopyralid will give the greatest long-term control
  • application costs – for large infestations the cost of treatment is often underestimated. The costs of retreatment also need to be considered.

The success of any herbicide application will depend on:

  • variation in herbicide application – large bushes are commonly under-sprayed. Foliar treatments must ensure that the inner leaves and canes of bushes are sufficiently wetted along with the outer canopy
  • seasonal timing of application – optimal time for treatment is during the active growth stage from flowering to fruiting (usually December to March). Translocated herbicides applied in autumn can achieve better kill rates as long as the plants are actively growing
  • the condition of the plant being treated – plants must be free of moisture stress or disease. Check that tips of canes have new, soft leaves
  • weather conditions at the time of treatment – temperatures over 30ºC can cause heat stress to plants, limiting uptake of herbicide, particularly when humidity is also high
  • the age of the plant – plants in their first year of growth are easier to kill with herbicides. Old, well-established thickets may require a number of treatments. At least 1 m of growth on canes is required for successful treatment
  • pre-control activities (e.g. slashing or burning) –after slashing or burning ensure enough regrowth, prior to herbicide applications
  • the species of blackberry – some species are more resistant to certain herbicides than others. Correct identification of the species and monitoring the results of the treatment are critical for successful control
  • the quality of the water used to mix herbicide – pH, water hardness and dirty water can all affect the results of a herbicide treatment. Use the best quality water available.

There are various ways of applying herbicides to blackberry infestations, depending on the size of the infestations and other aspects such as accessibility and proximity to waterways. For detailed information on selecting and applying herbicides for blackberry control, see the Blackberry Control Manual.

Table 2 – Herbicides for blackberry control.
Herbicide
(active ingredient)
Characteristics
Metsulfuron-methyl Absorbed through foliage and root system; recommended for initial treatment of large, dense infestations
Glyphosate Absorbed through foliage; recommended for small infestations that are easy to check and re-treat and areas where other herbicides cannot be used, such as in or near watercourses
Triclopyr Absorbed mostly through foliage; recommended for initial treatment of large infestations
Picloram Absorbed through foliage and roots; persistent in the soil;  useful where pellet formulations are considered the most appropriate technique
Picloram + Triclopyr****with or without aminopyralid Recommended for most infestations, both large and small; usually provides highest levels of control

Herbicide options

WARNING - ALWAYS READ THE LABEL
Users of agricultural or veterinary chemical products must always read the label and any permit, before using the product, and strictly comply with the directions on the label and the conditions of any permit. Users are not absolved from compliance with the directions on the label or the conditions of the permit by reason of any statement made or not made in this information. To view permits or product labels go to the Australian Pesticides and Veterinary Medicines Authority website www.apvma.gov.au

See Using herbicides for more information.


Glyphosate 360 g/L (Roundup®)
Rate: 10–13 mL per 1 L of water
Comments: Flowering to leaf fall. Use higher rate on old, dense infestations.
Withholding period: Nil.
Herbicide group: M, Inhibitors of EPSP synthase
Resistance risk: Moderate


Glyphosate 835 g/kg + Metsulfuron-methyl 10 g/kg (Trounce®)
Rate: 1 measured pack (173 g) per 100 L of water
Comments: Apply from flowering until before leaf yellowing. Do not apply to bushes with mature fruit.
Withholding period: Nil (recommended not to graze for 7 days before treatment and for 7 days after treatment to allow adequate chemical uptake in target weeds).
Herbicide group: B, Inhibitors of acetolactate synthase (ALS inhibitors) + M, Inhibitors of EPSP synthase
Resistance risk: High/Moderate


Hexazinone 250 g/L (Velpar® L)
Rate: Undiluted (4 mL per spot)
Comments: Bushes up to 1 m in height.
Withholding period: No stated withholding period.
Herbicide group: C, Inhibitors of photosynthesis at photosystem II (PS II inhibitors)
Resistance risk: Moderate


Metsulfuron-methyl 300 g/kg + Aminopyralid 375 g/kg (Stinger™)
Rate: 20 g per 100 L of water
Comments: Spray to thoroughly wet all foliage, Uptake spray oil or Pulse pentrant should be added.
Withholding period: 3 - 56 days (see label)
Herbicide group: B, Inhibitors of acetolactate synthase (ALS inhibitors) + I, Disruptors of plant cell growth (synthetic auxins)
Resistance risk: High/Moderate


Metsulfuron-methyl 600 g/kg (Brush-off®)
Rate: 10 g per 100 L of water
Comments: Apply when bushes are actively growing. Thoroughly wet all foliage and canes at commencement of flowering.
Withholding period: Nil (recommended not to graze for 7 days before treatment and for 7 days after treatment to allow adequate chemical uptake in target weeds).
Herbicide group: B, Inhibitors of acetolactate synthase (ALS inhibitors)
Resistance risk: High


Metsulfuron-methyl 600 g/kg (Brush-off®)
Rate: 1 g/L + organosilicone penetrant
Comments: Gas gun / Splatter gun application. Thoroughly wet all foliage and canes. Commence application at flowering as this indicates good growing conditions.
Withholding period: Nil (recommended not to graze for 7 days before treatment and for 7 days after treatment to allow adequate chemical uptake in target weeds).
Herbicide group: B, Inhibitors of acetolactate synthase (ALS inhibitors)
Resistance risk: High


Picloram 100 g/L + Triclopyr 300 g/L + Aminopyralid 8 g/L (Grazon Extra®)
Rate: 350 or 500 mL per 100 L water
Comments: Treat in late spring to autumn. Use an adjuvant.
Withholding period: Where product is used to control woody weeds in pastures there is a restriction of 12 weeks for use of treated pastures for making hay and silage; using hay or other plant material for compost, mulch or mushroom substrate; or using animal waste from animals grazing on treated pastures for compost, mulching, or spreading on pasture/crops.
Herbicide group: I, Disruptors of plant cell growth (synthetic auxins)
Resistance risk: Moderate


Picloram 20 g/kg (Tordon® Granules)
Rate: 35–45 g /m2
Comments: Apply granules over an area extending from main stem to 30 cm outside the drip line.
Withholding period: Nil.
Herbicide group: I, Disruptors of plant cell growth (synthetic auxins)
Resistance risk: Moderate


Picloram 44.7 g/kg + Aminopyralid 4.47 g/L (Vigilant II ®)
Rate: Undiluted
Comments: Cut stump/stem injection application. Apply a 3–5 mm layer of gel for stems less than 20 mm. Apply 5 mm layer on stems above 20 mm .
Withholding period: Nil.
Herbicide group: I, Disruptors of plant cell growth (synthetic auxins)
Resistance risk: Moderate


Triclopyr 200 g/L + Picloram 100 g/L (Tordon® DSH)
Rate: 500 mL per 100 L of water
Comments: Late spring to autumn treatment. Use an adjuvant.
Withholding period: Nil.
Herbicide group: I, Disruptors of plant cell growth (synthetic auxins)
Resistance risk: Moderate


Triclopyr 300 g/L + Picloram 100 g/L (Grazon® DS)
Rate: 350 or 500 mL per 100 L of water
Comments: Late spring to early autumn when bushes are actively growing. Use the higher rate on plants which have been damaged by grazing stock or insects.
Withholding period: Nil.
Herbicide group: I, Disruptors of plant cell growth (synthetic auxins)
Resistance risk: Moderate


Triclopyr 300 g/L + Picloram 100 g/L (Grazon® DS)
Rate: 335 mL per 10 L of water
Comments: Gas gun / Splatter gun application. Apply to actively growing bushes.
Withholding period: Nil.
Herbicide group: I, Disruptors of plant cell growth (synthetic auxins)
Resistance risk: Moderate


Triclopyr 600 g/L (Garlon® 600)
Rate: 170 mL per 100 L of water
Comments: Late spring to early autumn. Actively growing bushes. Do not use under dry conditions.
Withholding period: Nil.
Herbicide group: I, Disruptors of plant cell growth (synthetic auxins)
Resistance risk: Moderate


Triclopyr 600 g/L (Garlon® 600)
Rate: 280 L per 10 L of water
Comments: Gas gun / Splatter gun application. Good control will be achieved, similar to high volume application, where bush size enables good coverage of entire bush. The use of marking agent is recommended.
Withholding period: Nil.
Herbicide group: I, Disruptors of plant cell growth (synthetic auxins)
Resistance risk: Moderate


back to top

Biosecurity duty

The content provided here is for information purposes only and is taken from the Biosecurity Act 2015 and its subordinate legislation, and the Regional Strategic Weed Management Plans (published by each Local Land Services region in NSW). It describes the state and regional priorities for weeds in New South Wales, Australia.

Area Duty
All of NSW General Biosecurity Duty
All plants are regulated with a general biosecurity duty to prevent, eliminate or minimise any biosecurity risk they may pose. Any person who deals with any plant, who knows (or ought to know) of any biosecurity risk, has a duty to ensure the risk is prevented, eliminated or minimised, so far as is reasonably practicable.
All of NSW Prohibition on dealings
Must not be imported into the State or sold
All species in the Rubus fruiticosus species aggregate have this requirement, except for the varietals Black Satin, Chehalem, Chester Thornless, Dirksen Thornless, Loch Ness, Murrindindi, Silvan, Smooth Stem, and Thornfree
Central Tablelands Regional Recommended Measure*
Land managers should mitigate the risk of new weeds being introduced to their land. Land managers should mitigate spread from their land.
Protect conservation areas, natural environments and primary production lands that are free of blackberry
Hunter Regional Recommended Measure*
Land managers should mitigate the risk of new weeds being introduced to their land.
North West
An exclusion zone is established for all lands in the region, except the core infestation area comprising the Gwydir Shire council, Liverpool Plains Shire council and Tamworth Regional council
Regional Recommended Measure*
Whole of region: The plant should not be bought, sold, grown, carried or released into the environment. Exclusion zone: Land managers should mitigate the risk of new weeds being introduced to their land; land managers should mitigate spread from their land. Core infestation: Land managers reduce impacts from the plant on priority assets
Northern Tablelands Regional Recommended Measure*
Land managers should mitigate the risk of new weeds being introduced to their land. Land managers should mitigate spread from their land. The plant should not be bought, sold, grown, carried or released into the environment.
*To see the Regional Strategic Weeds Management Plans containing demonstrated outcomes that fulfill the general biosecurity duty for this weed click here

back to top


For technical advice and assistance with identification please contact your local council weeds officer.
For further information call the NSW Invasive Plants and Animals Enquiry Line on 1800 680 244 or send an email to weeds@dpi.nsw.gov.au

Reviewed 2017