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Explained in 60 Seconds: What to do about Giant Hogweed on your property.

Giant Hogweed in your garden

Earlier this month, Limerick city and county
councils began a three-year project to control the spread of Giant Hogweed on
the River Loobagh near Kilmallock.

WATCH: RTE Video Segment “Limerick three-year project to control
spread of Giant Hogweed”.

The plant is a public health hazard due to its
toxic sap. This article will explain how Giant Hogweed is removed and what to
do if you find it on your property.

How is Giant Hogweed removed?

Attempting to physically remove Giant Hogweed is not recommended, as cutting the plant releases its dangerous sap. Systemic glyphosate and triclopyr herbicide injections are the most effective means of control. These chemicals are broken down by soil microorganisms and do not pose a threat to the wider environment when used responsibly.

In early spring, when the plant is 20-50cm
tall, a stem injector gun is used on individual plants between the 1st
and 2nd nodes. At the end of May, further applications might need to
be carried out if the seedlings have germinated after the first treatment. As
seeds can persist in the soil, follow-up monitoring and control measures must
be carried out for at least 5 years. (Nielsen et al., 2005). Monitoring of a
site following the removal of any invasive species is vital, as any returning
plants can be easily spot treated to prevent re-establishment.

To manage and prevent further spread
of this invasive species, strands need to be identified. Education programs that
target the general public would be enormously beneficial.

Giant Hogweed
Identify Giant Hogweed

What should you do if you think you have found an invasive species on your property?

Attempting to manually remove certain
invasive plant species by hand can sometimes lead to further spreading.
Invasive species such as Giant Hogweed require a professionally trained
operator to remove them. Southern Scientific Services can advise you on the best action to take if
you think you have an invasive plant problem. We can provide you with an
Invasive Species Management Plan as well as undertaking control of invasive
species such as Rhododendron and Japanese Knotweed.

For further information, please contact our

Phone: 066 97 63588



  • Don’t
    physically remove Giant Hogweed. Cutting
    the root releases its dangerous sap.
  • Manual removal can also lead to further
  • Systemic glyphosate and triclopyr
    herbicide injections are the most effective means of control.
  • Giant Hogweed
    requires a professionally trained operator for removal.
  • If you think
    you have found an invasive species on your property, contact Southern
    Scientific for advice on the best action to take.

READ MORE: What is Giant Hogweed and Why is it a Threat?


Pyšek, P., Jaroˇsík, V., Hulme, P., Pergl, J., Hejda, M., Schaffner, U., Vilà, M., 2012. A global assessment of invasive plant impacts on resident species, communities and ecosystems: the interaction of impact measures, invading species’ traits and environment. Glob. Change Biol. 18, 1725–1737.

Vilà, M., Weiner, J., 2004. Are invasive plant species better competitors than native plant species? Evidence from pair-wise experiments. Oikos 105, 229–238.

Nielsen, C.; Ravn, H.P.; Nentwig, W. and Wade, M. (eds.), (2005). The Giant Hogweed Best Practice Manual. Guidelines for the management and control of an invasive weed in Europe. Forest & Landscape Denmark, Hoersholm.