The dyer's greenweed is a permanently growing shrub that resembles a broom and normally develops up to a height of 60 cm or two feet. The herb has firm branches with uncomplicated and interchanging leaves that appear like spears. The length of the leaves normally range between half to one inch and have soft stalks. The sprouts or tender branches of the herb have pointed ends that bear yellow colored and pea-shaped blooms which begin to blossom in the month of July. The dyer's greenweed flowers are half to three-fourth inch long and supported by little stalks that are smaller that the calyx. As in the case of the broom, dyer's greenweed flowers 'blow up' during visits by insects. The 'hooks' of the four base petals of the flowers are initially straight, but heavily strained and hence no sooner they are touched, they suddenly whorl downwards allowing the flower to split open. Once the flowers fade, tender pods appear in their place. These pods are around one inch long and highly condensed crossways. The color of the pods turn brown on ripening and each pod normally encloses 5 to 10 seeds.
In French, the dyer's greenweed shrub is known as Genêt des Teinturiers, while the Germans call the plant as Färberginster. During the 14th century, dyer's greenweed was known as Wede-wixin or Woud-wix in English and was later re-christened as Woad Waxen. In fact, we even find that the plant was known as Green Weed or Dyer's Weed in English long time ago.
The shrub is of a dwarf or midget variety and grows in bunches. Dyer's greenweed is found in abundance in the pastures almost all over England and is believed to make the poor soil fertile. Occasionally, cows grazing in the meadows consume this shrub and in such instances the plant imparts a bitter flavor to their milk. Even the cheese and butter prepared from the milk of cows that have consumed the shrub tastes horrible.
All parts of the dyer's greenweed shrub, particularly the blossoming tops of the shrub, produce an excellent quality yellowish dye that has been used by dyers since ages to manufacture this particular pigment. This pigment is especially used to dye wool and when it is blended with woad (a blue plant dye), the combination produces a brilliant green color. This color is made permanent by adding alum, cream of tartar or potassium bitartrate and sulphate of lime to the dye. In the olden days, poor people in some regions of England collected large quantities of the shrub from the meadows and sold them to the dyers to make a living.
In 1708, Tournefort had witnessed the method of dyeing cloth, linen, woolen and even leather using the pigment obtained from dyer's greenweed in the Samos Island and explained the matter in detail. Interestingly enough, in many regions of the Grecian islands, the same dyeing process is still followed by the dyers. In the olden days, even the Romans had extensively used the dyer's greenweed shrub to dye clothes and leather in the same procedure and this has been documents by several ancient Roman writers.
In addition to be extremely useful as a source of high quality dye, the dyer's greenweed also possesses several medicinal properties. Although the herb has never been acclaimed as a formal medicine, the blossoming tops as well as the seeds of the plant have been exploited therapeutically. The plant is known to have diuretic, cathartic and emetic properties and is often prescribed for enhancing urine outflow and as a purgative. The powdered seeds of the plant function as a gentle laxative, while a decoction prepared with the plant is often used therapeutically to heal dropsy or edema (build up of unwarranted fluids between the body tissues). The same decoction is also said to be beneficial in curing gout (swollen joints) and rheumatism (stiffness of joints and muscles) when ingested in dosages of a wine glassful thrice or four times daily.
The decoction prepared with dyer's greenweed may also be used with the cinders obtained from an alkaline salt to treat dropsy as well as other disorders, while a cream prepared with the dwarf shrub was known as Unguentum geneste. In the earlier days, the seeds of the plant formed an important ingredient in a plaster to repair disjointed limbs. Although there is not enough scientific evidence to support the claims, in the Ukraine, a decoction prepared with the dyer's greenweed was believed to be an effective medicine for treating hydrophobia.
Twigs, seeds and leaves.
The dyer's greenwood possesses a number of therapeutic properties. For instance, the leaves, twigs and the flowering stalks possess cathartic (purgative), diuretic, diaphoretic (promoting sweating), emetic, vasoconstrictor (a medication that causes the blood vessels to narrow) and stimulant attributes. Similarly, the seeds are powdered and taken internally, as they function in the form of a gentle purgative. In earlier times, these powdered seeds were also employed to create plasters to treat broken limbs. The whole dyer's greenweed plant is used to prepare a decoction, which has been employed to treat conditions like dropsy, gout and rheumatism. The fresh shoots of dyer's greenweed are also used to prepare a homeopathic remedy for rheumatism.
In addition to its medicinal uses, dyer's greenwood is also used for other purposes. The whole plant yields a superior quality yellow dye, which is obtained from the tender shoots and flowers. This herb also yields an excellent quality green dye when it is blended with woad or dyer's woad (botanical name Isatis tinctoria). Usually, this color is secured by adding alum, sulphate of lime and cream of tartar. In fact, you can dry out the stems of dyer's greenwood and store them till the time when you want to obtain the dye. The stems also yield a type of fiber that is employed to make rough cloth as well as cordage. The dyer's greenweed plants may also be used in the form of a ground cover provided you plant them at intervals of 45 cm each way.
Some people recommend using the seeds of dyer's greenweed as a possible substitute for coffee. Even the flower buds of this shrub are pickled and also utilized in the form of an alternative for capers. In addition, they are also used in the form of a vegetable.
Dyer's greenweed is indigenous to the Mediterranean region and the western regions of Asia. The herb has also been acclimatized to the conditions in North America. Normally, dyer's greenweed is found to be growing naturally in the moorland and uneven meadows.
Dyer's greenweed plants can be grown easily provided the soil is light and well drained and the plants are being grown in a place receiving full sunlight. This species also thrives well in base or acidic soils. Dyer's greenweed can tolerate extreme cold conditions - to the extent of -35°C. Plants of this species dislike any kind of disturbance to their roots and, hence, they must always be transplanted while they are still young. Occasionally, this herb is grown simply for the dyes that can be obtained from it and when grown for this purpose, this plant is considered to be a biennial and harvesting of the entire plant is done during the second year of its existence. While there is no need to prune the plants, you may cut them according to requirement when the flowering season is over, as this helps to keep the plants in shape. The plants are polymorphic, as a result of which several named varieties have been developed for their ornamental worth.
Dyer's greenweed is an excellent bee plant, in addition to being a favourite food for rabbits. Although cows too consume this plant, but doing so spoils their milk. Dyer's greenweed shares a symbiotic association with particular soil bacteria, which develop nodules and attach to the plant's roots, helping it to fix nitrogen from the atmosphere. While a portion of this nitrogen is utilized by the plants for their growth, some amount of it is also used by other plants that are growing in the vicinity.
This species is generally propagated by means of its seeds, which are ideally sown in a cold frame in autumn after keeping them in cold stratification for some time. Before sowing the stored seeds, soak them in tepid water for about 24 hours and plant them in a cold frame preferably in February. The germination of these seeds is good. Provided the seedlings have grown sufficiently large, you should pick them out and transplant them in separate pots before transplanting them outdoors during the summer.
Alternately, you may also propagate this species by planting cuttings of semi-mature wood in July. Each cutting should be roughly between 5 cm and 10 cm in length and necessarily having a heel. If you are using fully mature wood, the cuttings should be between 5 cm and 10 cm in length each having a heel. Plant these mature wood cuttings in a frame during the period between September and October. The percentage of growth is quite good. Transplant these cuttings outdoors after autumn soon after they have developed roots.
The shrub dyer's green is generally harvested during the early part of summer, because it bears blooms at that time. The plant as well as the flowers can be dried up for use in future. However, never store this plant in excess of 12 months, because the active elements contained by it begin to decompose after this period.