---Cultivation---Henbane is in such demand for medicinal purposes that it is necessary to cultivate it, the wild plants not yielding a sufficient supply. Both varieties were formerly cultivated in England, but at present the biennial is almost solely grown. Englishgrown Henbane has always been nearly sufficient to provide enough fresh leaves for the preparation of the juice, or green extract, but large quantities, chiefly of the annual kind, were imported before the War from Germany, Austria and Russia, in the form of dry leaves.
Henbane will grow on most soils, in sandy spots near the sea, on chalky slopes, and in cultivation flourishing in a good loam.
It is, however, very capricious in its growth, the seeds being prone to lie dormant for a season or more, refusing to germinate at all in some places, and the crop varying without any apparent reason, sometimes dying in patches. In some maritime localities it can be grown without any trouble. It requires a light, moderately rich and well-drained soil for successful growth and an open, sunny situation, but does not want much attention beyond keeping the ground free from weeds.
The seed should be sown in the open early in May or as soon as the ground is warm, as thinly as possible, in rows 2 to 2 1/2 feet apart, the seedlings thinned out to 2 feet apart in the rows, as they do not stand transplanting well. Only the larger seedlings should be reserved, especially those of a bluish tint. The soil where the crop is to be, must have been well manured, and must be kept moist until the seeds have germinated, and also during May and June of the first year. It is also recommended to sow seeds of biennial Henbane at their natural ripening time, August, in porous soil.
The ground must never be water-logged, especially in the first winter; it runs to stalk in a wet season. Drought and late frosts stunt the growth and cause it to blossom too early, and if the climatic conditions are unsuitable, especially in a dry spring and summer, the biennial Henbane will flower in its first year, while the growth is quite low, but wellmanured soil may prevent this.
Care must be taken in selecting the seed: commercial Henbane seed is often kiln-dried and useless for sowing. In order to more readily ensure germination, it is advisable to soak the seeds in water for twenty-four hours before planting: the unfertile seeds will then float on the top of the water and may thus be distinguished. Ripe seed should be grey, and yellowish or brown seeds should be rejected, as they are immature. Let the seeds dry and then sift out the smallest, keeping only the larger seeds.
Henbane seed being very small and light should be well mixed with fine dry soil as it is sown.
As seedlings often die off, a reserve should be kept in a box or bed to fill gaps, even though they do not always transplant success fully.
If it is desired to raise a crop of the annualvariety the plants, being smaller and not branching so freely, may be grown at a distance of 18 inches apart each way, but the annual is very little cultivated in this country.
If any annuals come up among the biennials sown, the flowers should be cut off until the leaves get larger and the stem branches.
There is usually some difficulty in growing Henbane owing to its destruction by insects: sometimes the whole of the foliage is destroyed by the larvae of a leaf-mining fly, Pegomyia Hyoscyami, and the crop is rendered worthless in a week. And when the large autumnal leaves of the first-year plants of the biennial variety decay, the large terminal bud is often destroyed by one of the various species of macro-lepidopterous caterpillars which hide themselves in the ground. The crown or bud should be covered as soon as the leaves have rotted away with soil mixed with soot or naphthaline, to prevent the depredations of these and other insects.
Floods may also rot the plants in winter, if grown on level ground. Potato pests are fond of the prickly leaves and will leave a potato patch to feed on the Henbane plant.
If mildew develops on the foliage in summer, dust the plants with powdered sulphur or spray with 1/2 oz. of liver of sulphur in 2 gallons of water.
When it is desired to preserve seed for propagation, it is well to cut off the top flowering shoots at an early stage of flowering (these may be dried and sold as flowering tops), and allow only about six seed-capsules to ripen. This will ensure strong seed to the capsules left, and this seed will probably produce biennial Henbane, weaker seeds being apt to produce the less robust and less valuable annual Henbane.
Seeds sown as soon as ripe in August may germinate in autumn, and thus constitute a biennial by growing on all through the winter and flowering the next summer.
Although the cultivation of Henbane in sandy ground near the sea, especially on the rich soil of estuaries, would probably pay well, it is hardly a profitable plant to grow in small gardens, more especially as the yield of dried leaf is very small. It is estimated that about 15 cwt. of dry herb are obtained from an acre of ground.
---Harvesting---Much of the efficacy of Henbane depends upon the time at which itis gathered. The leaves should be collected when the plant is in full flower. In the biennial plant, those of the second year are preferred to those of the first; the latter are less clammy and foetid, yield less extractive, and are medicinally considered less efficient. Sometimes, however, the plant is destroyed by a severe winter in England, and then no leaves of the second year's growth are obtainable, and it has been suggested that this is, perhaps, one of the causes of the great uncertainty of the medicine as found in commerce.
The leaves of the biennial variety are collected in June or the first week of July and those of the annual in August.
The leaves and flowering tops which constitute the 'Second Biennial Henbane' are collected either with or without the smaller branches to which they are attached and carefully dried, unless they are required for the preparation of the juice or green extract, when they should be sent to the distillery at once on cutting.
The herb when required in the fresh state should be cut the first week in June, because in the second week the leaf-mining insect attacks the leaves, leaving only patches of white epidermis.
The herb requires very careful drying, as its properties are liable to be in great measure destroyed if kept too long in a damp state.
The fresh herb loses 80 to 86 per cent of its weight on drying, 100 lb. yielding 14 to 20 lb. of dry herb.
The fresh leaves have, when bruised, a strong, disagreeable narcotic odour, somewhat like that of tobacco: their taste is mucilaginous and very slightly acrid. The characteristic odour disappears to a large extent on drying, but the bitter taste then becomes more pronounced.
When the dried leaves are thrown upon the fire they burn with a crackling noise from the nitrate they contain, and at the same time they emit a strong odour.
The dried drug consists principally of the flowering tops. In commerce, it is commonly found in irregular rounded or flattened masses, in which the coarsely-toothed hairy bracts, the yellowish corolla with deep purple lines and two-celled ovary, with numerous ovules, can easily be identified.
The root is not employed in medicine, but experiments have shown that the seeds not only possess all the properties of the plant, but have ten times the strength of the leaves. They are also employed in pharmacy, having been much used in the Middle Ages. At the present time, they are much prescribed by the Mohammedan doctors of India.
The seed should be gathered in August; it may be kiln-dried for medicinal purposes, but the treatment renders it useless for culture, and if required for propagation seeds should be sun-dried. The capsules should be harvested before the lids split off, the seeds then being shaken out and dried in the sun.
(2) http://www.erowid.org/psychoactives/cultivation/cultivation_growing-the-hallucinogens.shtml#HENBANE
Cultivation and Propagation: Henbane does well in most soils, as it is found wild in dry waste places. It is propagated easily by seed. Henbane seed is very viable. I have sprouted seeds collected from a capsule on a plant that had gone through a winter's rain and hard frost and had almost deteriorated away, and got 90 percent germination. The seed should be planted in May or when the weather is in the 70's. It should be sown very thinly in rows 2 to 3 feet apart. The bed should be kept moist until sprouting, and the seedlings should be thinned to 1.5 to 2 feet apart in the row. They may also be sown in flats at room temperature and transplanted out on a cool day. Henbane is sometimes attacked by potato pests and will occasionally mildew like tomato plants.
Harvesting: Henbane leaves and tops should be collected when the plant is in full flower. This is usually in June, July, or sometimes August. The leaves should be dried quickly in the sun, as it will lose its properties if kept in a damp state too long. The herb will lose approximately 80 percent of its weight in drying. Fresh henbane leaves have a fetid order when handled, which they lose upon drying. The seed is up to ten times as strong as the leaves. The capsules may be gathered in August, before they open. The seeds are shaken out and dried in the sun if to be used for growing purposes, or dried quickly at a low heat if to be used psychoactively.