One phormium bush will afford 20-50 roots suitable for transplanting. The number of roots planted together varies from 1 to 8. When planting wide, 2-3 roots may be placed in a spot ; but if close planting be adopted, one root alone will suffice. Care must be taken to avoid planting roots which have thrown up a seed-stem, or those from the centre of an old plant ; the latter are not so productive as young roots, and will manifest a tendency to flower, thereby absorbiog more nourishment than all the leaves. For this reason, the flower-stalks of the plants should be removed as early as possible, either by twisting off, or by cutting, and rubbing the wound with a little dry earth, to prevent " bleeding." Diseases and Enemies.—Care must be taken to keep cattle from the plantation, or they will chew the leaves till only the fibre remains, and, where the leaves have been cropped, will draw out the young leaves to obtain the butts. Fires must also be guarded against. Attention is specially directed to a small " looper " caterpillar, about 1 in. long, which in some districts of New Zealand has been found to attack the nether side of the leaves in early summer, and eat away the fibre in patches /-2 in. long and in. broad, causing an extra proportion of tow to be scutched out during the preparation of the fibre. Plants growing in sheltered places are most attacked, as the insect cannot so readily attach itself where the leaves are kept in motion by the wind.
Cropping.—Phormium grows in bunches or groups of plants or shoots, each shoot having 5 leaves; as 10 shoots on the average are contained in a bunch, each group will have about 50 leaves. These last vary in length from 3 to 10 ft., and each consists of a double-bladed leaf, which, when closed, is 2-4 in. wide. The plants are not ready for the first cutting till the 5th-8th year, according to the favourable character of the conditions under which they are grown. When every leaf is quite out down, the plant will send up 4-6 full-sized leaves within the first year. If 2-3 of the centre leaves of each fan are left untouched, the cropping may be repeated annually, yielding each time 4-5 leaves. How long this treatment may be continued is not ascertained : it is probable that the plants will be gradually weakened, and will finally die out. It is also likely that plants which are cut annually will not send out as many new fans as those left entire. It would appear that after 13-14 months, the leaves commence to decay, and are then no longer of economic value. The usual period for removing the leaves (in New Zealand) is December-January. No appreciable difference can be discovered in the quantity or quality of the fibre yielded by leaves of various ages (within the two years' limit). The maturity of the leaf is ascertained by, its texture and firmness, or by its being split at the point, or by the recurring of the blades from the central midribs. The top of the
leaf should feel soft to the touch, and droop a little. It is generally conceded that only the outer leaves should be cut, and that, in doing so, great care should be taken not to injure the leaves which enclose the central shoot. With this view, the knife should be inserted at the leaf enclosing the central shoot, and the outside leaves, 2-3 on each side, be cut downwards and slanting outwards. No leaf should be cut before arriving at maturity, which it does in 6 months from its first appearance, as this weakens the plant, and makes it liable to go to flower.
Production.—On the best land, an acre may contain 2000 bunches of the plant, or 100,000 leaves. These leaves, after cutting off the gummy and useless butts, and drying in the sun, weigh about 5 to the lb., so that an acre may give nearly 10 tons of sun-dried leaves. When the outer leaves only are taken, the quantity will be reduced to 4 tons. Assuming a yield of 15 per cent. of clean fibre upon these 4 tons, the return should be 12 cwt. an acre, to which may be added about 8 cwt. of tow. The weight of green leaf required to produce 1 ton of fibre is stated by different authorities as follows :-5/ tons, 5/ tons, 6 tons, 6i tons, 61 tons, 7 tons, 7-8 tons. To obtain 2000 bunches to the acre, however, the planting must be very close.
Extraction and Preparation of the Fibre.—Before describing the modern machinery invented for the extraction and preparation of this fibre, a few lines may be devoted to a consideration of the native methods, since all our mechanical skill has not been able to obtain a product approaching in quality that of the Maories.
Native methods.--(a) In preparing the Swamp variety for fine purposes, the natives select clean unspotted leaves of 12-18 months' growth, and, cutting off the upper leaf at about 6 in. below the point where the two blades adhere, reject the lower leaf, and the coloured edges and keel. The fibre is stripped only from that side of the leaf which was innermost when the blades were joined, the under side is cut across, and then with the smooth rounded edge of a mussel-shell, the row of upper fibres is torn away, with the cuticle adhering. The fibre is next scraped with the same shell, to remove as much as possible of the cuticle; when 12-20 leaves have been thus treated, they are thrown into a tub of water, to be kept moist till sufficient is ready to be taken down to a stream, where it is washed and scraped repeatedly till quite clean, then hung up to dry, and after wards worked in the band. Thus at most only 4 the fibre contained in a leaf is utilized : / the leaf is discarded, and I the fibre of the other is rejected.