Maßnahmen gegen Nichtheimische, gebietsfremde und invasive Tiere und Pflanzen Informationserteilung

Biennial to perennial, herbaceous and flowering from July to September - the so-called Hercules perennial, which, however, is not a perennial, also known as giant hogweed. Region of origin: Caucasus. Because of its size (up to 3.50 m) and the large white umbel, it is beautiful to look at, but also poisonous. For several decades, the perennial with the white umbel flowers has been spreading rapidly. It finds good conditions on fallow land and banks. One plant reproduces with up to 50,000 seeds, which can germinate for up to 10 years. The light and buoyant seeds spread along waterways, roads and railways. In order to consistently push back the plant, it is necessary to also control the populations on private property, otherwise they can spread again from there. The assistance of citizens is therefore required and an appeal is made to the owners of affected private property to undertake the removal of giant hogweed.

Precaution:

• Avoidance of spreading (garden waste, beekeepers, etc.) and restriction of spread (flowing waters, compost waste, etc.)
• Education and information (flyers, training).

Protective measures:

The following measures must be observed when controlling giant hogweed to prevent adverse health effects:

• Protective clothing is essential (gloves, protective clothing, safety goggles and respiratory protection if necessary).
• If possible, remove plants under overcast skies, rainy weather, and only light winds or at dusk.
• Face and hands should be additionally protected with high SPF sunscreen.
• Prevent confusion with other plant species (ore angelica) (Nature Conservancy).

Control Methods:

Control of Hercules perennial is lengthy and labor intensive. Therefore, control outside of one's own garden should be carried out at the community level together with experts. The following control methods are available:

• Weeding of seedlings in early spring, young plants in spring/fall.
• Tilling or plowing the plants in spring, when the growth is just beginning, and pulling out the rootstocks
• Cutting off the topmost rootstock with a sharp spade about 15 cm below the soil surface in early spring (until April) and in fall
• Cutting off the seed stalks before seed ripening from mid-July (beware of plant sap splashes). It is important to avoid dropping the seeds, because they will ripen. Dieback of the mother plant from autumn
• Grazing: short-term by pigs (fresences also roots, small stands), perennial with sheep, goats and dark-skinned breeds in larger stands.

Recommended under conditions:

• Digging of individual plants (up to 200 expl.) in spring.
• Cutting off inflorescences during full bloom (too early leads to new growth)
• Mowing: On larger contiguous areas mowing of the plants (height 0.5 - 1 m) is suitable. It is best to start shortly before flowering. At this time the plant is weakened the most. However, once started, mowing must be repeated about 6 - 8 times/a at the beginning and during flowering, or 5 - 6 times at intervals of 10 days each, since the species will produce flowers again as early as 14 days after mowing, sometimes at a height of less than 10 cm.

Not recommended:

• Herbicide applications and other chemicals: major risks due to environmental effects (accompanying flora, amphibians, people in the vicinity, discharge into water bodies, etc.).

Control:

• Permanent removal includes multi-year follow-up inspections beginning in the spring, as seed may still be in the soil and germinate years later. Combined methods as indicated under control. Dense sods prevent seeds lying on the ground from germinating.

Disposal:

• Commercial composting especially of cones and whole plants.
• Commercial incineration especially of the cones and whole plants.

All parts of the plant of Hercules Periwinkle contain a phototoxic substance, furanocoumarin, which reaches the skin on contact with the plant sap. Upon exposure to sunlight and subsequent irradiation with UV-A, furanocoumarin forms an antigen together with endogenous protein, which leads to a strong allergic reaction. Mild reactions are itching, redness, swelling, more severe are fever, sweating, circulatory shock and blistering reminiscent of a severe burn (1st to 2nd degree) and discoloration that can last for weeks (photodermatitis). (cf. Kowarik 2003). Even withered stems and flowers as well as the seed still contain effective furanocoumarin. The treacherous thing is that no visible reaction is yet apparent immediately after contact. The greatest risk from sun exposure is half an hour to 2 hours after skin contact.

What to do if you come into contact with Hercules perennial herb?

If you have touched Hercules perennial or if you suspect that you have done so, you should immediately avoid the sun. The affected areas, even if no reaction is visible yet, should be washed thoroughly with soap and water, better with methylated spirits, and treated locally with creams and lotions containing glucocorticoids. It makes sense to apply a sunscreen cream afterwards. The sun should also be avoided for the next 2 to 3 days.

Consulting: State Office for the Environment, Nature Conservation and Geology Mecklenburg-Western Pomerania
Execution: Ordnungsämter of the municipalities or district administrations