Bedding plants

Recognizing and fighting the ambrosia plant - tips against allergy weeds

Hardly any plant is as aggressive as the ragweed plant. Only a few pollen can make a healthy person an allergy sufferer. There is only one way to protect yourself from this. The allergy monster has to go.

Ambrosia plant with flowersUntil a few years ago, the ambrosia plant, also known under the name "Mugwort leaved ragwort", was mainly native to America. Due to the global movement of goods and the progressive climate change, the plant was able to spread in Europe. Hungary, France and Italy are particularly affected, but Germany is no longer immune to the insidious plant. With devastating consequences.

The pollen of the ragweed plant has become one of the most common allergy triggers for hay fever patients (source: erkaeltet.info). Hardly any other plant can cause the allergic reactions to be as violent as it is. A single plant can emit up to a billion pollen, which can then germinate for several decades. The pollen is so small that it easily penetrates so deep into the bronchi that in the worst case even asthma can occur.
"By the way: People who have never had allergies before can have an allergic reaction to the ragweed plant. So nobody is immune from it and therefore there is only one option. Get rid of the weeds.

Bird food contaminated with ragweed seeds

Climate change and global trade in goods are not the only causes of the growth of the horrendous plant. The seeds are also in the bird feed that we offer to feed our domestic birds in winter.

This is because sunflower seeds and the weeds' fruit heads ripen and are harvested together. In recent years, bird feed has become “cleaner”, but not one hundred percent. Even with seed bags labeled “Free from ragweed seeds” it is not always guaranteed that there will be no seeds here.

In order to protect your own garden and reduce the general multiplication, it is advisable to do the bird food yourself for the winter.

Recognizing Ambrosia plants: 6 important characteristics

Recognizing an ambrosia plant is not easy. It is very similar to other plants in our area. So it is particularly regarded as a double of common mugwort. But the wild carrot and wormwood are confusingly similar to her.

So that you can avoid confusion, I would like to mention a few special features of the Ambrosia plant. In addition, the Bavarian State Research Center for Agriculture has published a table that shows the most important distinguishing features between mugwort and ambrosia. Of course, I don't want to withhold this from you either.

➜ Ambrosia identifying features

  • Stem: The hairy stem is green at first and then turns reddish to violet over time. It is very robust and has strong branches.
  • Leaves: The leaves of the ambrosia plant are green on both sides.
  • Blossoms: The flowers are in different places. The female flowers are located directly in the leaf axils, while the male ones rise up as grapes and spray their yellow pollen during the flowering period in July.
  • Location: The Ambrisoa plant is not only found in gardens, but also on the side of the road, along railway tracks and in green areas. Vacant lots are also a very popular place.
  • Growth: If the location is very dry, the mugwort-like plant will only grow about 10 to 15 cm high. However, if the soil is rich in nutrients, the plant can even grow to a considerable size of 2 meters when it rains a lot.
  • Growth / flowering: In contrast to mugwort, the ragweed plant grows rather slowly in the first months, only between mid and late June does the plant begin to grow quickly in order to develop the first flowers in late July or early August.

Comparison ambrosia / mugwort

characteristicCommon mugwortambrosia
leavesUnderside lighter, silvery-white coloredGreen on both sides
stalkGlabrousHairy, green, red in autumn
developmentFaster (approx. 25 - 50 cm at the end of May)Slow (approx. 10 - 20 cm at the end of May)
floweringFrom the end of JuneFrom mid / late July
inflorescencePyramidal inflorescenceElongated male flowers are racemose at the shoot end, yellowish when pollen is formed

(Source: lfl.bayern.de)

Fighting the ambrosia plant - 4 tips

Report ragweed plant
At watson.jki.bund.de you will find a central registration office for Ambrosia plants. The website is maintained by the Julius Kühn Institute and records all find data on a map.

Tear out the plants together with the roots and then dispose of them in the household waste. Do not throw the plant in the organic waste or on the compost, as the plant can spread freely here.

If the plant has already formed flowers, you should first cut off the flower stalk and then pull the plant out with its roots, otherwise the plant would regenerate itself quite quickly. Wear a dust mask for safety to protect yourself from the pollen.

Since the seeds have been germinating for many decades, as mentioned above, you should check the affected areas annually for re-emergence.

Also, especially examine your bird feeding places for ragweed plants. It is always best if the plant does not flower at all. This will reduce the risk that the pollen will fly through the air and the plant will find a new place to spread out.