The only currently active legislation on weeds and invasive plants in South Africa forms part of the Conservation of Agricultural Resources Act, 1983 (Act No 43 of 1983) (CARA). Regulations 15 and 16 under this Act, which concern problem plants, were amended during March 2001. CARA is currently (2011) in the process of being revised.
The National Environmental Management: Biodiversity Act (Act No 10 of 2004) (NEM:BA) also has a chapter dealing with alien species and invasive species, which is relevant to this subject. The regulations in terms of this chapter have, however, not been finalized, and as a result this chapter cannot be implemented yet.
A lot of useful information on CARA can be found on the website of the Working for Water Programme.
Legislation regarding noxious weeds is nothing new in South Africa. As early as 1860, spiny cocklebur (Xanthium spinosum) was declared a noxious weed in the Cape Peninsula, and even before the promulgation of the Noxious Weeds Act, No 42 of 1937, the various Provincial Administrations were charged with the enforcement of legislation on the compulsory eradication of weeds.
The present legislation forms part of the Conservation of Agricultural Resources Act, 1983 (Act No 43 of 1983) (CARA). Regulations 15 and 16 under this Act, which concern problem plants, were amended during March 2001. These changes were necessitated by the accelerating deterioration of the country's natural resources due to invasion by alien plants, as well as a heightened public awareness with regards to environmental matters.
Contents of the new legislation
Whereas CARA previously classified problem plants into two groups - declared weeds and plant invaders - the amended regulations make provision for four groups: declared weeds (Category 1 plants), plant invaders (Category 2 and Category 3 plants) and indicators of bush encroachment. The first three groups consist of undesirable alien plants and are covered by Regulation 15. Bush encroachers, which are indigenous plants that require sound management practices to prevent them from becoming problematic, are covered separately by Regulation 16.
Which plants have to be controlled?
The actions required with regard to any plant species depend on the category in which the plant appears in Table 3 of the amended regulations, and might differ from province to province. In certain cases, special conditions were added that apply only to that specific species.
Category 1 plants, or declared weeds
These are prohibited plants that will no longer be tolerated, neither in rural nor urban areas, except with the written permission of the executive officer or in an approved biocontrol reserve. These plants may no longer be planted or propagated, and all trade in their seeds, cuttings or other propagative material is prohibited. They may not be transported or be allowed to disperse.
Plant species were included in this list for one or more of the following reasons: they might pose a serious health risk to humans or livestock, cause serious financial losses to land users, be able to invade undisturbed environments and transform or degrade natural plant communities, use more water than the plant communities they replace or be particularly difficult to control. Most of the plants in this category produce copious numbers of seeds, are wind or bird dispersed or have highly efficient means of vegetative reproduction. Whereas some of these plants were introduced inadvertently, have no obvious function to fulfil in South Africa and are generally regarded as undesirable, many of them are popular garden or landscaping plants. What they all have in common, however, is the fact that their harmfulness outweighs any useful properties they might have. Care was taken not to include a plant in this category if part of the population of South Africa would suffer because of its absence. The ornamentals in this category ought to be reasonably easy to replace with less invasive substitutes.
The following species are declared weeds (Category 1 plants):
Woody plants (trees or shrubs): several Australian Acacia species (A. implexa, A. longifolia, A. paradoxa and A. pycnantha); two lebbeck trees (Albizia lebbeck and A. procera); Mauritius thorn (Caesalpinia decapetala); four cestrum species (Cestrum aurantiacum, C. elegans, C. laevigatum and C. parqui); triffid weed (Chromolaena odorata); Montpellier and Scotch broom (Cytisus monspessulanus and C. scoparius); three hakeas (Hakea drupacea, H. gibbosa and H. sericea); all seed producing species or seed producing hybrids of Lantana that are non-indigenous to Africa (this excludes the creeping, purple-flowered Lantana montevidensis, which does not produce seeds in South Africa); Australian myrtle (Leptospermum laevigatum); Indian laurel (Litsea glutinosa); purple loosestrife (Lythrum salicaria); cat's claw creeper (Macfadyena unguis-cati); tree daisy (Montanoa hibiscifolia); the single-flowered varieties of oleander (Nerium oleander); wild tobacco (Nicotiana glauca); lesser broomrape (Orobanche minor); stinkbean (Paraserianthes lophantha); four ornamental granadilla-like species (Passiflora caerulea, P. mollissima, P. suberosa and P. subpeltata, but not the edible Passiflora edulis); pereskia (Pereskia aculeata); Australian cheesewood (Pittosporum undulatum); the ornamental Durban guava (Psidium x durbanensis); wax tree (Rhus succedanea); bloodberry (Rivina humilis); eglantine (Rosa rubiginosa); American bramble (Rubus cuneifolius); red sesbania (Sesbania punicea); silverleaf bitter apple (Solanum elaeagnifolium); bugweed (Solanum mauritianum); Spanish broom (Spartium junceum); yellow bells (Tecoma stans); yellow oleander (Thevetia peruviana); Indian almond (Triplaris americana) and European gorse (Ulex europaeus).
Succulents: chandelier plant (Bryophyllum delagoense); queen of the night (Cereus jamacaru); torch cactus (Echinopsis spachiana); harrisia cactus (Harrisia martinii); jointed cactus (Opuntia aurantiaca); long spine cactus (O. exaltata); sweet prickly pear (O. ficus-indica - but excluding all spineless cactus pear cultivars and selections); creeping prickly pear (O. humifusa); imbricate cactus (O. imbricata); small round-leaved prickly pear (O. lindheimeri); drooping prickly pear (O. monacantha); rosea cactus (O. rosea); saucepan cactus (O. spinulifer) and pest pear of Australia (O. stricta).
Herbaceous plants: burweed (Achyranthes aspera); crofton weed and mistflower (Ageratina adenophora and A. riparia); two ageratums (Ageratum conyzoides and A. houstonianum); camel thorn bush (Alhagi maurorum); Madeira vine (Anredera cordifolia); moth catcher (Araujia sericifera); two Mexican poppy species (Argemone mexicana and A. ochroleuca); pom pom weed (Campuloclinium macrocephalum); the small-flowered Indian canna (Canna indica - but not the common ornamental species or cultivars); balloon vine (Cardiospermum grandiflorum); spear thistle (Cirsium vulgare); field bindweed (Convolvulus arvensis); two dodder species (Cuscuta campestris and C. suaveolens); three thorn apple species (Datura ferox, D. innoxia and D. stramonium); two echium species (Echium plantagineum and E. vulgare); four species of ginger lilies (Hedychium coccineum, H. coronarium, H. flavescens and H. gardnerianum); pepper-cress (Lepidium draba); parthenium weed (Parthenium hysterophorus); kudzu vine (Pueraria lobata); potato creeper (Solanum seaforthianum); wild tomato (Solanum sisymbriifolium); Mexican and red sunflower (Tithonia diversifolia and T. rotundifolia) and two cocklebur species (Xanthium spinosum and X. strumarium).
Grasses or reeds: Spanish reed (Arundo donax); pampas grass (Cortaderia selloana and C. jubata) - excluding sterile varieties of C. cordata; nassella tussock (Nassella trichotoma); white tussock (Nassella tenuissima); fountain grass (Pennisetum setaceum - excluding the sterile cultivar 'Rubrum') and feathertop (P. villosum).
Aquatic plants: red water fern (Azolla filiculoides); dense water weed (Egeria densa); water hyacinth (Eichhornia crassipes); Canadian water weed (Elodea canadensis); parrot's feather (Myriophyllum aquaticum); spiked water-milfoil (Myriophyllum spicatum); water lettuce (Pistia statiotes) and Kariba weed (Salvinia molesta).
Plants that are problematic only in certain areas, but are popular ornamental or utility plants elsewhere, were declared weeds (Category 1 plants) only in certain provinces. These include:
- Silver wattle (Acacia dealbata), spider gum (Eucalyptus lehmannii) and leucaena (Leucaena leucocephala) - Category 1 in Western Cape, but Category 2 elsewhere.
- Two tamarisk species (Tamarix chinensis and T. ramosissima) - Category 1 in Northern, Western and Eastern Cape, but Category 3 elsewhere.
- Coral tree (Ardisia crenata) and camphor tree (Cinnamomum camphora)- Category 1 in only Northern Province, KwaZulu-Natal and Mpumalanga, but not subject to legislation elsewhere.
- Pitanga (Eugenia uniflora), moonflower (Ipomoea alba) and morning glory (Ipomoea indica) -Category 1 in Northern Province, KwaZulu-Natal and Mpumalanga, but Category 3 elsewhere.
- Brazilian pepper tree (Schinus terebinthifolia) and Singapore daisy (Telechitonia trilobata) - Category 1 in KwaZulu-Natal, Category 3 elsewhere.
The dagga plant (Cannabis sativa), which used to be a declared weed, has been removed from the list because it is covered by the Narcotics Act.
Plant invaders of Category 2
These are plants with the proven potential of becoming invasive, but which nevertheless have certain beneficial properties that warrant their continued presence in certain circumstances. CARA makes provision for Category 2 plants to be retained in special areas demarcated for that purpose, but those occurring outside demarcated areas have to be controlled. The exception is that Category 2 plants may also be retained or cultivated in biological control reserves, where the plants will serve as host plants for the breeding of biological control agents. The growing of Category 2 plants in a demarcated area qualifies as a water use, and is subject to the requirements of section 21 of the National Water Act, 1998 (Act No. 36 of 1998).
An area can only demarcated for the growing of Category 2 plants by the Executive Officer. The land user needs to obtain a water use license; the plants have to primarily serve a commercial or utility purpose, such as a woodlot, shelter belt, building material, animal fodder, soil stabilisation, medicinal or own consumption; the conditions under which they are cultivated, have to be controlled; all reasonable steps have to be taken to curtail the spreading of seeds or vegetatively reproducing material outside the demarcated area, and all specimens outside the demarcated area have to be controlled. The Executive Officer has the power to impose additional conditions to ensure the adequate control of Category 2 plants in demarcated areas.
Seed or other propagative material of Category 2 plants may only be sold to, and acquired by, land users of areas demarcated for the growing of that species, or for the establishment of a biocontrol reserve. Category 2 plants may not occur within 30 m from the 1:50 year flood line of watercourses or wetlands, unless authorisation has been obtained in terms of the National Water Act. The Executive Officer has the power to grant exemption from some of the above requirements.
The following species are classified as Category 2 plants: rooikrans (Acacia cyclops); silver wattle (A. dealbata) - this species not allowed in the Western Cape; green wattle (A. decurrens); black wattle (A. mearnsii); Australian blackwood (A. melanoxylon); Port Jackson willow (A. saligna); sisal hemp (Agave sisalana); old man salt bush (Atriplex nummularia); beefwood and horsetail (Casuarina cunninghamiana and C. equisetifolia) - neither of which will be allowed for dune stabilisation; several species of gum trees (Eucalyptus camaldulensis, E. cladocalyx, E. diversifolia, E. grandis, E. paniculata, E. sideroxylon and E. lehmannii) - the latter species not allowed in the Western Province (because of their importance for beekeepers, legislation with regard to Eucalyptus species might still be changed; they might be exempted from the need of being controlled wherever they occur outside demarcated areas and, instead, control might only be mandatory in or near watercourses and wetlands); honey locust (Gleditsia triacanthos), St John's wort (Hypericum perforatum), which may only be grown under controlled conditions; leucaena (Leucaena leucocephala) - this species not allowed in the Western Cape; several pine species (Pinus canariensis, P. elliotti, P. halepensis, P. patula, P. pinaster, P. radiata, P. roxburghii and P. taeda); white and grey poplars (Populus alba and P. x canescens); honey and velvet mesquite (Prosopis glandulosa and P. velutina), as well as their hybrids; the commercial guava (Psidium guajava); castor oil plant (Ricinus communis); black locust (Robinia pseudoacacia), which may be propagated as a rootstock only, and then only with special authorisation ; watercress (Rorippa nasturtium-aquaticum); European blackberry (Rubus fruticosus); the weeping and crack willows (Salix babylonica and S. fragilis) - not to be confused with the indigenous Salix mucronata, which should not be removed; and Johnson grass (Sorghum halepense).
Plant invaders of Category 3
These plants are undesirable because they have the proven potential of becoming invasive, but most of them are nevertheless popular ornamentals or shade trees that will take a long time to replace. A few of them were placed into this category instead of into category 1 because they do not cause problems in all situations. In terms of Regulation 15 of CARA, Category 3 plants will not be allowed to occur anywhere except in biological control reserves, unless they were already in existence when these regulations went into effect. The conditions on which these already existing plants may be retained are that they do not grow within 30 m from the 1:50 year flood line of watercourses or wetlands, that all reasonable steps are taken to keep the plant from spreading, and that the Executive Officer has the power to impose additional conditions or even prohibit the growing of Category 3 plants in any area where he has reason to believe that these plants will pose a threat to the agricultural resources.
Propagative material of these plants, such as seeds or cuttings, may no longer be planted, propagated, imported, bought, sold or traded in any way. It will, however, be legal to trade in the wood of Category 3 plants, or in other products that do not have the potential to grow or multiply. The Executive Officer will have the power to grant exemption from some of the above requirements.
The following species are Category 3 plant invaders: pepper tree wattle (Acacia elata); pearl acacia (Acacia podalyriifolia); tree-of-heaven (Ailanthus altissima); sponge-fruit salt bush (Atriplex lindleyi subsp. Inflata); two species of orchid trees (Bauhinia purpurea and B. variegata); two species of cotoneasters (Cotoneaster franchetii and C. pannosus); loquat (Eriobotrya japonica); pitanga (Eugenia uniflora) - but not allowed in Northern Province, Mpumalanga or KwaZulu-Natal; Australian silky oak (Grevillea robusta); moonflower (Ipomoea alba) - but not allowed in Northen Province, Mpumalanga or KwaZulu-Natal; morning glory (Ipomoea indica) - but not allowed in Northen Province, Mpumalanga or KwaZulu-Natal; another species of morning glory (Ipomoea purpurea); jacaranda (Jacaranda mimosifolia); five species of privets (Ligustrum japonicum, L. lucidum, L. ovalifolium, L. sinense and L. vulgare) - L. lucidum may be propagated only as a rootstock if special permission has been obtained; St Joseph's lily (Lilium formosanum, also incorrectly called Lilium longiflorum); "syringa" (Melia azedarach); New Zealand christmas tree (Metrosideros excelsa); giant sensitive plant (Mimosa pigra); white mulberry (Morus alba) - excluding clutivar 'Pendula',- may be propagated only as a rootstock , if special permission has been obtained (note that the black mulberry, Morus nigrum, which is the better fruit tree of the two, is not subject to legislation); manatoka (Myoporum tenuifolium subsp. montanum, also sometimes called M. acuminatum); sword fern (Nephrolepis exaltata) - excluding its cultivars; belhambra (Phytolacca dioica); 'Abyssinian' coleus (Plectranthus comosus); pickerel weed (Pontederia cordata); strawberry and Durban guavas (Psidium cattleianum and P. x durbanensis); yellow and Himalayan firethorn (Pyracantha angustifolia and P. crenulata); Brazilian pepper tree (Schinus terebinthifolius) - but not allowed in KwaZulu-Natal; three senna species (formerly known as cassias) (Senna bicapsularis, S. didymobotrya and S. pendula); jambolan (Syzygium cumini); rose apple (Syzygium jambos); Chinese and pink tamarisk (Tamarix chinensis and T. ramosissima) - neither of which is allowed in the Northern, Western or Eastern Cape; the tipu tree (Tipuana tipu) and the toon tree (Toona ciliata).
The amended regulations stress that, when controlling plants that occur in areas where they are not allowed, methods should be used that are appropriate for the species concerned as well as to the ecosystem in which they occur. One or a combination of the following control methods may be used: uprooting, felling, cutting, burning, treatment with registered herbicides, biological control or any other recognised and appropriate method. Repetitive follow-up actions will be mandatory until the required control has been achieved.
The aim of control is to reach a point where, ideally, the plants concerned do no longer occur in that particular area or, at least, where the plants can no longer grow, produce viable seeds or spores, coppice, sprout or produce root suckers, reproduce vegetatively, propagate themselves in any other way, or spread into other areas. If this is not possible, the plants have to be contained and their multiplication limited as far as possible.
When controlling weeds and invaders, damage to the environment has to be limited to the minimum. CARA does not specify the types of environmental damage that might be caused by control actions, but a few examples would be:
- the removal of or herbicidal damage to non-target plants
- the chemical pollution of soil or water or any other threat to non-target organisms
- the irresponsible use of fire
- the creation of a fire hazard by allowing flammable material to accumulate in fire-sensitive areas
- unnecessary or irresponsible disturbance of the soil, especially on riverbanks or slopes
- failure to rehabilitate denuded areas so as to prevent soil erosion and invasion by other undesirable species
- any other action that might upset the ecological balance of the environment.
Biological control of weeds is subject to rigorous regulations, and will be recognised by CARA as a valid control method only if it is practised in accordance with all these regulations. Biological control involves the use of host-specific natural enemies of weeds or invaders from the plant's country of origin, to either kill or remove the invasive potential of these plants. It may only be initiated by and carried out under the supervision of an academic or research institute or organisation established by legislation, which practises and researches biological control of weeds and invader plants. In order to prevent the waste of biocontrol research effort, money and natural enemies, CARA also lays down certain rules for the protection of biological control agents. In areas where biological control is effective, no additional control methods should be used that would harm the biocontrol agents. Provision is made for certain areas to be set aside as biological control reserves, i.e. areas in which a number of invasive plants are maintained as host plants for the biological control agents, to ensure the continued presence of the agents in that area. Only the Executive Officer may designate a biological control reserve, on condition that it is used by a biocontrol expert to rear and redistribute biocontrol agents. In such a biological control reserve, no measures may be applied that would render the biocontrol agents ineffective.
Nothing contained in Regulation 15 may be used as a reason for ignoring or circumventing any other laws.
Declared indicators of bush encroachment concern only landowners in rural areas and are covered in Regulation 16 of CARA. Bush encroachment is a term used for "stands of plants of the kinds specified in Table 4 where individual plants are closer to each other than three times the mean crown diameter". Plants in this group are not alien plants, but indigenous plants that tend to become abnormally abundant when the area is degraded by e.g. overgrazing or injudicious fires.
A list of indigenous plants that might indicate bush encroachment in specified areas of the country (Table 4) appears in Regulation 16. The list includes plants such as sickle bush (Dichrostachys cinerea) and sweet thorn (Acacia karroo), but the complete list will not be reproduced here.
The plants themselves are not the problem, but they can be regarded as a symptom of poor land management practices. Therefore CARA does not outlaw these plants, but instead prescribes management practices aimed at preventing bush encroachment, and at combating it where it already occurs. If communities of plants from the list of indicators occur in the natural vegetation of an area, the land users have to take the necessary precautions to prevent the deterioration of their land to such an extent that bush encroachment takes place. In cases where bush encroachment has already taken place, the land users have to remove the cause of deterioration and combat the encroachment of indicator species. Among the prescribed measures are the uprooting, felling or cutting of plants, the judicious application of registered herbicides, livestock reduction and the correct utilisation and protection of veld. Regulations 9, 10 and 11 of CARA contain details of livestock reduction and veld utilisation and protection. The Executive Officer may also impose any additional requirements, control methods or strategies by means of a directive.
Who will administrate this legislation, and how will it be enforced?
CARA is administered by the National Department of Agriculture (DoA), through its Direcorate: Land Use and Soil Management (D:LUSM).
The Executive Officer is mentioned repeatedly in the regulations, usually in connection with the granting of permission for certain actions, or the making of decisions. The Minister of Agriculture has designated the Director: Land Use and Soil Management as Executive Officer where CARA is concerned. The Director has in turn delegated his powers to the Resource Auditors. Applications for the designation of demarcated areas, or applications for exemption from any of the requirements of CARA, should be addressed to the regional office of D:LUSM - see table 1.
Table 1. Regional offices of D:LUSM
||Private Bag X120, Pretoria, 0001
||(012) 319 7560
||(012) 329 5938|
||P.O. Box 3620, Pietersburg, 0700
||(015) 295 4175/6
||(015) 291 1936|
||P.O. Box 1665, Nelspruit, 1200
||(013) 755 1420
||(013) 755 1961|
||P.O. Box 2557, Potchefstroom, 2520
||(018) 294 3343
||(018) 297 4642|
||P.O. Box 2303, Kimberley, 8300
||(053) 831 1793
||(053) 83 3101|
||P.O. Box 34521, Faunasig, 9325
||(051) 861 2171
||(051) 861 1024|
||P.O. Box 545, Durbanville, 7551
||(021) 976 8136
||(021) 976 1889|
||Private Bag X3917, North End, Port Elizabeth, 6056
||(041) 487 1734
||(041) 484 4552|
||P.O. Box 285, Queenstown 5340
||P.O. Box 345, Pietermaritzburg 3200
||(033) 345 3557
||(033) 394 6161|
The Resource Auditors of D:LUSM, who are the law enforcement officers, may delegate some of their powers to employees of a local authority, who would then become municipal weed inspectors.
Resource Auditors and Municipal Weed Inspectors are authorised to visit any property at a reasonable time to inspect it for the presence of declared weeds or invader plants. If category 1, 2 or 3 plants occur contrary to the specifications of Regulation 15, the land user will be informed of the offence as well as of the steps that should be taken to correct it. The time needed to control the offending plants will be determined through consultation with the land user, and deadlines will be set for certain phases of control. The Resource Auditor will confirm the decisions taken during the personal visit by issuing a written directive. The property will be visited again as deadlines become due, to ascertain whether the necessary control actions have been carried out satisfactorily. If not, the Resource Auditor has the power to prosecute. A municipal weed inspector does not have the power to issue a directive, but only a notice, and cannot prosecute offenders. If the land user does not comply with the actions required by the notice, the case will be handed over to a Resource Auditor.
The penalty for non-compliance with the requirements of CARA could be a fine of up to R5 000 or imprisonment of up to two years, or both, for a first conviction. This could be doubled at a second or subsequent conviction.
Anybody who considers himself aggrieved by a directive issued by a Resource Auditor may appeal to the Director-General, and anybody aggrieved by any other decision or action in terms of this Act may appeal to the Minister. The appeal should be lodged within a prescribed time, and a prescribed amount will have to be paid. This amount, or part of it, will be refunded if the appeal succeeds.
HENDERSON, L. 20001. Alien weeds and invasive plants. A complete guide to declared weeds and invaders in South Africa. Plant Protection Research Institute Handbook No. 12. Agricultural Research Council, Pretoria. 300 pp. (Contains a complete copy of the relevant CARA regulations.)