There were many important feast days when it came to gathering herbs and flowers in Poland but the single most important date occurred on the church celebration of the Assumption of the Blessed Virgin Mary on August 15. So vital was this day that it was, and still is, called  Matka Boska Zielna, Our Lady of the Herbs. On this special feast day, every village woman brought a bouquet of flowers, plants and herbs to church in order to be blessed by the priest.  

In the Pomorze area, the northwest section of Poland, they have a saying on this day: "Każdy kwiat woła, weź mnie do koscioła!" (Every flower calls, take me to church!)

The women gathered whatever plants or greenery grew in their region, or the herbs and flowers they especially loved or needed. In the Mazowsze and Podlasie area took hyssop, southernwood, lavender, and mullein.  They also took lovage, branches of the  hazel tree, hemp and mint. Both herbs from the garden and the wild were gathered. These included poppy(Polish: mak), peony (Polish: piwonia, sage (Polish:szalwia), thyme (Polish: macierzanka), tansy (Polish: wrotycz), dill (Polish: koper), caraway (Polish: kminek), mugwort (Polish: bylica), chamomile (Polish: rumianek) (Kolberg Krakowskie I 1962: 227) Since the feast day coincided with the time of the harvest, it was also customary to take a few spikes of  various grains such as rye(Polish: żyto), wheat (Polish: pszenica) or oats (Polish: owies)

 The gathered and blessed herbs were used in endless ways: as part of wedding rituals, and death practices but mostly, medicinally. In  the country villages there were few practicing physicians. Isolated and often poverty stricken, they were usually left to their own devices to treat themselves as best they could, utilizing various herbs and plants. All the plants and herbs were felt to be stronger, more effective for having been blessed. The most popular, most well known medicinal plants, and frequently brought to church included:

Mugwort (Artemesia vulgaris) Polish: Bylica. Depending on their symptoms, mugwort was used to bathe a person back to health; used in poultices, it helped in pain along the spine or back as well as ease the pains of childbirth. If gathered from nine different areas helped women in situations where they were unable to conceive.
Southernwood (Artemesia abrotanum) Polish: Boze Drzewko. Universally used in treatment of bruises and contusion by application of poultices
Wormwood (Artemisia absinthium) Polish: Piołun. Wormwood appears all over Poland in wastelands and roadsides as well as in established herb gardens. The old herbals advised that an infusion of the dried leaves as a tea as a treatment for bad breath arising from the stomach, dispelling stomach gas, improving digestive juices and at the same time can build appetite.
Chamomile (Matricaria chamomilla) Polish: Rumianek. An infusion of the flower was taken for a fever, stomach troubles or various women's issues such as infertility or overlong menstruation.  A compress of chamomile applied to the brow relieved headache, and was applied to wounds and to the eyes when suffering from a sty.
Mullein (Verbascum Thapsis) Polish: Dziewanna. A tea brewed from the dried or fresh flowers was used for illnesses of the chest and difficulty breathing.  Fried with butter it was used to gray pimples and other skin eruptions and burns.
Coltsfoot ( Tussilago farfara) Polish: Podbiał pospolity. Found in every home medicine cabinet it was used for skin rashes, scrapes and tears of the skin on the arms and legs; for a cough and difficulty breathing and as a tea for most respiratory complaints.
Comfrey(Symphytum officinale)Żywokost. This plant is one of the best loved of all healing herbs. This tall, hairy leaved plant was used to heal broken bones, tears of the flesh  and also for the aches of rheumatism. It was used both externally and internally. A deconcoction from the leaves, or flowers treatedrespiratory disorders. The root mashed together with an animal fat was used as a poultice for sprains and broken bones. 
Elderberry (Sambucus Nigra L) Polish: Dziki bez czarny. A common plant through all of Europe, elderberry was also called bez lekarski, i.e., medicinal elderberry, to indicate its medicinal properties. The juice from the berries was especially beneficial for coughs. It would pull away the inflammation from infected wounds when the leaves and the skin were mixed with chalk and applied to the wounds.
Horsetail (Equisetum arvense) Polish: Skrzyp polny. This was also a much valued plant for its diuretic properties and as an infusion utilized for problems with the bladder or kidneys but must herbals caution that it must be on the weaker side as it is powerful and could weaken the individual.
Linden(Tilia cordata) Polish: Lipa drobnolista. From ancient times the linden was considered a sacred tree. It was so powerful that the fibers of the linden tree could tie up a devil. Branches of linden which had decorated an altar on the feast of Corpus Christi protected the house against lightning, when planted among a field of cabbage would protect it against bugs;  teas made from the flower of linden was used to treat chronic cough, mucous and phlegm in the chest and larynx, to make one sweat.
Nettle (Utica diocia L) Polish: Pokrzywa. A tea made from the leaves of nettle for respiratory troubles, chiefly coughs. The leaves  and stems were mashed and mixed with sugar which made a syrup within a few  days.
Plantain (Plantago maior L )Polish: Babka zwyczajna, the mashed leaves are applied to the skin for wounds and ulcers.
Thyme (Thymus Serphyllum) Polish: Macierzanka. Used in the treatment of rheumatism. When bathed in it, it treated skin ailments and added to teas to treat gastrointestinal ailments.
Yarrow (Achilla millefolium) Polish: Krwawnik. This plant was used in poultices for inflamed and pus filled cuts and wounds by mashing and applying it  to the wound. For the treatment of arthritis it is made into a liniment by soaking it in spirytus(alcohol) for 24 hours and applying to the limbs.
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