Hogweed - carefully, you can get burned!
Hogweed - widely and diversified plants. Different types of hogweed are grown as ornamental plants, some as silage for livestock feed, some suitable for human consumption. In recent decades, cow parsnip have been widely mentioned only as pests.
Hogweed (Heracleum) Is a genus of plants of the Umbrella family, with approximately 60–70 species distributed in the temperate zone of the Eastern Hemisphere (one species in North America). Some species contain photosensitizing substances (furanocoumarins) that cause photochemical burns in humans and large mammals. At the same time, hogweed is a powerful absorber of carbon dioxide and carbon monoxide and a powerful producer of oxygen.
Description of Hogweed
Hogweed - mainly biennial, rarely perennial grasses. Stems in different species ascend to different heights - from 20-50 cm to 250 cm; as a rule, they are hollow, with rare pubescence or pubescent along the entire length (in northern species).
The leaves are collected in a basal rosette, long-leaved, very large; can be ternary, twice ternary or pinnately separate, with segments of various shapes.
The flowers are small, white, less often greenish-yellow or bright pink, collected in complex umbrellas up to 40 cm across. Most species bloom in June, but flowering in different species continues until July-August.
The fruit is a two-seeded seed of a special type, called the ovule. Seeds ripen in July - September, easily crumble.
Hogweed are monocarpic plants, that is, they bloom only once in a lifetime and die off after ripening.
About 40 species grow in Russia and the CIS countries. In the European part of Russia, in Western Siberia and Kazakhstan it is widespread Siberian hogweed (Heracleum sibiricum).
In connection with the cultivation Hogweed Sosnowski (Heracleum sosnowskyi) as a silage culture, it became widespread, gradually moving to the wild, sowing the banks of reservoirs, vacant lots, road right lanes, uncultivated sections of fields. Thus, the rapid spread of hogweed violated the ecological balance and became a serious problem in European countries. In Germany, the Czech Republic, the Scandinavian countries, Estonia, Belarus, there are governmental and public programs to combat hogweed.
In Russia, the northern, northwestern, and central regions are particularly problematic in the distribution of hogweed. The spread is epidemic, and decisive action to prevent it was not taken in a timely manner, which led to a significant population of wildlife with this weed, dangerous for people and animals.
The name and history of the hogweed
In Russian, in ancient times, hogweed was called "borsch". In ancient times, this word meant something jagged. According to one version, this name was given to the plant for the shape of the leaves. In German, Dutch and Danish, hogweed is called the “bear paw”.
The young greens of some plants of this genus (mainly Siberian hogweed) were used to prepare dishes, which for this reason were also called "borsch". In addition to hogweed, vegetables were included in such dishes, and hogweed almost ceased to be consumed over time. Since the 18th century, “borsch” already means beetroot soup, and the plant itself in the literary language began to be called “hogweed”.
The Latin name Heracleum comes from the name of the hero of ancient Greek mythology Heracles, and was given by Linnaeus for the gigantic (compared to other umbrella) sizes of plants of this genus, as well as for the high growth rate of shoots.
Skin damage from hogweed
During the growing season, photodynamically active furocoumarins, substances that sharply increase the body's sensitivity to ultraviolet radiation, accumulate in different parts of the hogweed (in the leaves, stems, fruits of many species). The hogweed causes the most severe burns in contact with the skin on clear sunny days. But in order to get a burn, it is enough for both a short and light exposure of the sun to the skin area stained with the juice of the plant. Their contact with the skin leads to deep dermatitis, acting as a burn.
The presence of coumarins and furocoumarins in hogweed juice, which increase the body's sensitivity to the perception of sunlight, is the main "evil" of these plants. Juice that has fallen on the skin under the influence of sunlight (ultraviolet light) can enhance pigmentation of the skin of humans and animals, and cause dermatitis, which is often called "burns."
As a rule, a burn of the second degree (blisters filled with liquid) occurs on the affected areas of the skin. The burn manifestation time is from several hours to several days. The particular danger is that touching the plant for the first time does not give any discomfort.
Most often, dermatitis from the ingestion of hogweed juice on the skin is expressed in blisters, replaced by dark spots, which disappear within 3-6 months. With significant skin lesions, after a year, relapses of brown spots on the skin after burns are possible with a new exposure to the sun.
Hogweed juice in eyes can lead to blindness. Cases of loss of vision were noted by children who played with hollow stems of the plant as with telescopes. If hogweed juice affects 80% or more of the surface of the human body, then this can lead to death.
The photodynamic (photosensitizing) properties of furocoumarins are manifested not only with their local contact with the skin, but also with the ingestion of drugs. On this effect of coumarins, many creams and sprays for tanning have been created, as well as drugs for the treatment of vitiligo.
Methods of dealing with hogweed
1. Pruning of flowers during budding and the beginning of flowering
This is the most effective way to destroy hogweed in small areas. But he is also one of the most dangerous - it is easy to sprinkle with the juice of plants and get strong dermatoses in different parts of the body.
When pruning generative organs in a cowberry, it is important to cut only buds, flowers, or small green, undeveloped fruits. So you need to trim the central umbrella and first-order umbrellas. Umbrellas of the second and subsequent orders, if they are formed, can be cut off under the base of this umbrella. To do this, an umbrella is wrapped around the bottom with a protected hand (gloved) and only flowers are cut.
Strictly observe the rules of personal protection so that the juice of hogweed or dew with the juice from the plants dissolved in it does not fall not only on unprotected parts of the body, but also does not wet clothes.
If the deadlines for pruning buds, flowers of hogweed by hand have still been missed, and all the plants are simply beveled, you need to carefully monitor that new side umbrellas do not appear from the roots in the basal rosette. As soon as the plant gives new umbrellas, and the flowers in them form the ovaries, this means that there will be a new generation of seeds, sufficient to restore the thickets of this plant.
A very effective way of destroying hogweed seeds precisely during their ripening period. It is important not to miss the moment of the event. It is better to carry it out before the full ripening of the fruits in the central, largest umbrella.
This method requires maximum care and accuracy. Before burning, you can douse the plants with flammable liquid (so that it is the umbrellas with fruits that are wetted). During the burning of umbrellas, it is important to observe all safety precautions - in fact, flammable essential oils will stand out from the fruits of the hogweed.
It is important to observe fire safety, and try not to allow the juice of plants to get on open areas of the body and clothing.
3. Herbicide treatment
It is possible to use different types of herbicides: roundup, tornado, grantap, etc. The processing time is from the beginning of the growth of hogweed, and always before flowering. The treatment of plants with herbicides from the beginning of seed maturation is already less effective.
Frequent and intensive treatments will be effective for generative plants, starting from the moment the generative shoot develops and only until flowering begins. In other periods of the life of the hogweed, apart from vegetating young plants, treatment with herbicides will not give a significant effect. For monocarpic plants after flowering die off on their own, without the use of herbicides.
Doses (concentration) of the applied herbicides for treating cow parsnip should be double or even triple from those prescribed in the instructions for the corresponding type of herbicide. The effect can be achieved with two repeated treatments with a break between them of 15-20 days.
When treating hogweed with herbicides, it is necessary to ensure that the drug falls not only on the leaf surface, but also flows through the petioles into the leaf outlet; and moisten the generative shoot and inflorescences quite abundantly with the herbicide (umbrellas, if they are developed by the time of treatment).
Nevertheless, experiments are needed to evaluate such effects not only on hogweed plants, but also on the surrounding nature (on other, accompanying local species, on insects, small animals, etc.).
4. Agrotechnical measures
If plowing is possible, then it must be carried out several times during the growing season. The first plowing should be carried out shortly after the moment of exit to the site.
It is best to trim the hogweed roots using plane cutters. The depth of processing at the horizon is 5-10 cm. It is important to cut off the growth point of cow parsnip (they are characterized by geotropism - deepening the growth point below the soil level), which plants tighten by 3-5 cm or even 7-10 cm. The depth of the location of the kidney depends on the type of soil, climatic conditions of the region.
In the case of plants growing from the roots after the first plowing, it is important to carry out the second treatment until the leaves unfold and the inflorescences are brought to the surface.
For the complete destruction of all hogweed plants, plowing will need to be carried out for several years (depending on the clogging of the site with seeds) - from 2-3 to 5-7 years.
In autumn, plowing in areas overgrown with cow parsnips should not be carried out. For this will contribute to the accumulation of seeds in the soil, and then the eradication of cow parsnip will stretch for several more years.
5. Individual way
In early spring, as soon as the plants begin to grow, it is time to go with a bayonet shovel to destroy the cow parsnip. It is very important to have a well-sharpened (sharp) chancer tool.
It is necessary to cut, cut down the point of growth of the hogweed below the root neck. If you cut down above, then on the root of the plant there will remain several sleeping buds in the leaf sinuses - then they will go to growth and give seeds. The laying and development of generative structures in cow parsnip occurs, especially in the northern regions of the country, in the year of vegetation.
Small annual shoots of hogweed can easily be destroyed by weeding with hoe, as well as regular dump plowing.
Hogweed shoots can appear not only in the spring, but also during the summer (due to the high quality of the seeds). Therefore, weeding should be carried out repeatedly every 3-4 weeks, starting from the moment of growing hogweeds. It is important to prevent the flowering of new plants.
6. Use of remediators
In areas where the destruction of cow parsnip is carried out, the introduction of new plant species that can be used to restore land is possible. In this case, fast-growing and highly productive cereals (for example, rumps) or legumes (goat or galega) can be introduced into the fields.
As an option, intensive cultivation of row crops (potatoes, for example) is possible to remove hogweed from sites.
Intensive plowing, frequent weeding is the way to destroy the seedlings of hogweed, a sharp decrease in seed formation and re-seeding of plots.
This is an effective way to destroy hogweed only on condition that it will be carried out before the plants exit "into the tube", i.e. necessarily before flowering hogweed. And no later than 3-4 weeks after the first mowing. This technique is needed to destroy ALL generative shoots of hogweed, bearing inflorescences, and, accordingly, flowers. It is important not to let the cow parsnip bloom so that new seeds do not form.
And if mowing hogweeds only once in the middle of flowering - this will only contribute to further propagation of plants.
What can not be done, destroying thickets of cow parsnip
1. You can not mow hogweed at the end of flowering and the beginning of fruit set. Because it will not have the desired effect, unless the mowed plants are immediately destroyed immediately after mowing.
Mowed cow parsnips should immediately be put into heaps and burnt. Perhaps the fruits of plants can only be destroyed by burning or in another similar and affordable effective way.
2. It is impossible to leave the beveled cow parsnip abandoned in place. After all, the generative shoot of hogweed has a large supply of nutrients in the stem - sufficient to allow ripened seeds to ripen in the main umbrella of the fallen plant. Even hogweed seeds that have reached the wax phase of ripeness can give life to new plants.
3. Mowing of cow parsnips at the time of shedding seeds from plants should not be allowed. For this will lead to a greater dispersion of the hogweed.
If you cut off the umbrellas of the plant when the fruits have ripened on them, and especially do it in windy weather, this will help spread the seeds to new territories.
4. You must not be undressed or have unprotected parts of the body while working with cow parsnip. Best to wear waterproof clothes, since the juice of plants, absorbed into the clothes, touches the body and penetrates into it. Hogweed juice that is not washed off from the body during the day when sunlight (ultraviolet) is exposed to these places will lead to the formation of dermatitis by the type of burns.
First aid for burns from hogweed
If, in the fight against hogweed, nevertheless, the body contacted with the juice of the plant, then it is necessary.
- if possible, rinse the affected skin with plenty of soap in running water as soon as possible.
- rinse (rinse, not wipe) the affected parts of the body with an alcohol-containing liquid (cologne, vodka, alcohol).
In case of burns from hogweed juice, the affected areas must be treated.
- sodium usninate on fir balsam;
- liniment synthomycin.
Do not use any dressing. Conduct all activities traditionally prescribed for skin burns.
If severe burns occur, seek medical attention.
The use of hogweed
The plant contains alkaloids, furocoumarins, essential oils, sugars, protein, resins, ascorbic acid, carotene, tannins, arginine, and trace elements.
Despite the phototoxicity of the juice of many plant species, the leaves, stems and young shoots of many species of cow parsnip - in particular Siberian hogweed (Heracleum sibiricum) - edible in raw, salted and pickled form, serve as a seasoning for soups. Tender young stems with flowers (not yet developed) are used in salt form (doused with boiling water), as well as fried in oil with flour. The stems that have not yet had time to harden are eaten raw.
Hairy Hogweed (Heracleum villosum) is edible as a spice; it is also used in the production of pickled cheese in the Caucasus.
Suitable for livestock young plants common hogweed (Heracleum sphondylium).
Hogweed of Sosnowski (Heracleum sosnowskyi) was introduced into the culture at the end of the 40s of the XX century as a high-yielding feed (mainly silage) plant. Sosnovsky’s borschovik is characterized by high productivity - more than 2500 centners per hectare and high sugar content - up to 3% of fresh weight.
Some species, for example, Hogweed Mantegazzi (Heracleum mantegazzianum) and some others are decorative.
In some regions, young growing hogweed leaves are used to add to vegetable or meat soups. Also, young growing shoots of hogweed were pickled, salted, made candied fruit from the stems, dried leaves, pre-soaked or boiled them to remove essential oil and coumarin compounds. Sugar-rich hogweed roots obtained sugar and drove vodka.
In some regions of the Caucasus, cow parsnip are popular in the diet of humans and animals.
In folk medicine, a decoction of the roots is used as a sedative for epilepsy, seizures, various nervous and skin diseases accompanied by itching. Water infusion of the herb - as an antispasmodic and appetite-stimulating agent for catarrh of the stomach and intestines, digestive disorders, diarrhea, dysentery (5 teaspoons of ground root are infused in 2 cups of cooled boiling water for 8 hours and drunk during the day, or 3 teaspoons of the herb are infused 2 hours in 2 glasses of boiled water and drink in 4 divided doses). Poultices from fresh leaves of the plant are used for rheumatic joint pain.
In Tibetan medicine, the roots of a plant called “bruzza” are part of the medicinal prescription for the treatment of gallstone disease and kidney disease, and a decoction of the fruit is drunk with furunculosis.
Dry (overwintered) stems of hogweed inflorescences have been used since ancient times in Russia for the manufacture of a folk musical instrument - kalyuki, a kind of overtone flute. Currently, such stems are also used for the manufacture of rain sticks (musical instrument, genus percussion).
What methods do you fight against this weed?