The information on this page relates to available management measures for giant hogweed. Please visit the dedicated giant hogweed species account for more general information on this species.
Legislation mentioned in the following resources may not necessarily apply to Northern Ireland, but may relate to GB or Ireland. Not all legislation may be listed and will inevitably change from time to time. It is the responsibility of the individual to ensure that they are aware of and follow all legislation relevant to work carried out and any changes to it.
The NIEA Widely Spread Species Management Measures Questionnaire (Terrestrial Plants) was produced to help highlight some of the key information that must be considered when developing management measures for a invasive non-native spices. The accompanying guidance notes provides a summary of some of the available management measures which should be used to complete the questionnaire.
Manual control works well for dealing with single plants or small infestations that can be eradicated with a small amount of labour.
Considerations for manual control of giant hogweed:
The sap of Giant Hogweed contains a toxic chemical which sensitises the skin and leads to severe blistering when exposed to sunlight – this reaction can re-occur for many years every time the skin is exposed to sunlight
The degree of symptoms will vary between individuals with children being known to be particularly sensitive
Victims are unaware of the damage being done as touching the plant is painless
The cut material or sap on the skin remains active for several hours after cutting
Hand cutting should never be undertaken unless the operator is wearing full protective clothing to prevent skin contamination by the sap Giant hogweed root tapping/cutting;
Giant hogweed root tapping/cutting;
Infestations need to be controlled by digging out the whole plant as cutting through the stem must be done below ground level to ensure damage to the rootstock and to prevent regrowth from the base. This is known as ‘tap rooting’ (see images below)
Cut the taproot approximately six inches below ground level using a spade, shovel, or anything with a large sharp edge.
In areas with erosion or on steep inclines (where additional soil may be covering the plant base), plants may need to be cut up to ten inches below the soil.
When cutting the root you need to separate the thick stem base bearing old leaf scars from the root below.
To prevent re-sprouting, the taproot should be severed below the caudex or root crown (where the stem becomes the root)
If possible (for your safety), cut the plants before the leaves are very large.
The cut part of the plants should be removed from the soil and left out to dry (safest for control person) or bagged and disposed of.
If the plants do not die, cut them again when they regrow
When using the root-cutting method, another attack strategy is to apply herbicide to the cut root remaining in the soil to help ensure no part of the root grows back the following year
Survey the site for up to 7 years after the last growth as remaining seeds may be viable and regrow.
Further information on available management measures can be found in the resources listed below.
RAPID – Good Practice Management – Giant hogweed
Guidance Note – Management of Giant hogweed
The following resources also provide further information on management measures for giant hogweed;