The Garden.

Otago Witness, Issue 1296, 30 September 1876, Page 18

The Garden.

SEEDS AND SEED-RAISING.

Seeds are capable of enduring extremes of temperature, which would prove fatal to the living plants of which they are the produce. The length of time during which seeds of certain plants will retain their vitality is uncertain,, but' it must in many cases be very considerable. Plants' of the Raspberry, Gooseberry, and Strawberry have' been raised from seeds contained in jam made from the fruit of these plants, such seeds having necessarily endured for some considerable time, a temperature exceeding 212°, the point at' which water boils. The great length of time during which some seeds will remain in the soil in a dormant condition, although to all appearance under circumstances favourable to germination, is very, remarkable. Some twenty years ago the central parts of some large flower-beds' here were planted with the common White Petunia (P. nyctaginiflora), and notwithstanding that, every season since those beds' have been occupied by various other kinds of bedding plants, no season has passed during which an abundant crop of seedling Petunias has not appeared upon them, although the Penuias have never since that time been allowed to flower in them. Similar instances have been, observed in the case of Verbenas, Heliotropes, Pelargoniums, and other species of plants. Althongh many kinds of seeds maintain their vitality apparently undiminished for a great length of time when buried at certain depth in the earth, 1 yet, when harvested in the usual way, a gradual diminity at once ensues, and it is generally found that the newer the seeds' are, the larger is the per-e'entage that will; germinate, and per-centage will be found to diminish with each succeeding' season ; and, as a general rule, few kinds' of seed can be depended upon for a crop, after the second year. With some kinds it is even unsafe after the first. I h'avei never known a seed* of the Perilla nankinensis to germinate if more than a year old, and this is also the ca&e with regard' to many others ; while, on the other 1 hand, seeds of the Pelargonium will germinate even in a green and apparently unripe condition, and the plants so produced will generally be found to be more robust than those from seeds more thoroughly matured.- But, as luxuriant development is, to ' some extent, opposed to fertility, it consequently follows that in the case of such annual plants as the Melon and the Cucumber, old seeds, or seeds not less than two years old, are to bo preferred to newer ones. The eeeds of some leguminous and other plants are encased in a somewhat hard shell of covering, which generally causes them to lie for a considerable time in the soil before they germinate ; but growth may in most cases be greatly accelerated by pouring hot or even boiling water upon the seeds, and allowing them to remain in it two or three days before sowing them. Very old seeds of various kinds, which would not, under ordinary circumstances, germinate at all, may sometimes be induced to do so by the application of certain chemical substances, such as oxalic acid, newly slaked lime, &c. The ordinary condition, however, necessary to induce seeds to germinate are, exclusion of light, and maintaining a certain amount of moisture and heat, the latter, of course, varying in accordance with the requirements of different species. The seeds of many of our most; common indigenous plants or weeds will germinate in soil at a temperature but little above the freezing point (32°) ; and it has been even asserted recently that Beeds have been found tb germinate in grooves formed by blocks of ice. An earth tamperature, however, varying from 50° to 60°, may be considered as that most favourable to the germination of the seeds of plants indigenous to Europe, while a bottom heat of from 70° to 80° or upwards will be necessary to start into growth seeds of plants which are natives of tropical countries. In England it is found that the seeds of many flowers, as well as those of some culinary plants, will not germinate until the seed has attained a certain degree of warmth, or, if they do grow, the low temperature in which the embryo plants are placed generally proves very prejudicial, if not fatal, to them. It is, therefore, never advantageous, but frequently the reverse, to sow seeds even of the common garden Beet, which is a variety of Beta vulgaris, and a native of the South of Europe, earlier than the first week of April. Such a course is also to be recommended in the case of the Scarlet Runner and tho several varieties of Dwarf Kidney Beans, &c, while the Tropreolum perogrinum, or Canary flower, a well-known decorative climbing plant, being a native of Peru, and, consequently, tender, is commonly sown under glass in a slight bottom-heat, and planted out when the season is somewhat advanced, but even then it generally sustains a con-

siderable check. •It is ;found to answer better to defer the sowing of the seed of this favourite climbing plant' until some time during the first half oi the month of April, or until the soil 1 has become somewhat warm, and then to . sow it in the open air where tbe plants are;intended to flower. A very considerable portion of seeds of all kinds when sown in, -the open air during dry weather .either p'e,rjsh altogether or germinate irregularly, and are consequently exposed, for a long time to the attacks of birds and mice. It is therefore always advisable in the case of large seeds, such as those of Beans and Peas, not only to steep them in rain-water for twenty-four hours or longer before sowing them, but also to, pour abundance of water into the trench or .drill prepared for them, and, as soon as the seeds are sown, to cover them up immedietely. • In the case of smaller Beeds, sueh 7 as those of the different varieties of sthe- Brasaica tribe — Lettuces, Endive, &c, whenever it is necessary to sow during dry weather, the seeds should be previously steeped in water and afterwards partially ; dried, in order that they may be evenly sown ; the soil, too,' intended for ; their reception should be well watered before the sowing takes place. And when the seeds have been gently pressed into the moist soil, and covered with it (the .covering,- of course, varying in accordance, with the size of the seeds,) the surface should be made smooth and level,' and- at • once covered with bast mats, or pieces of frigi domo, or any similar material which r will combine the effects of excluding light, protecting the seeds from birds, and retaining to some extent the moisture in the soil ; under such circumstances £he seeds will generally germinate freely, and care must afterwards be taken' tb remove the covering soon after growth, has taken place, selecting, if possible) a showery or dull day for effecting this removal, .' The various kinds of flower seeds sown in the open air, such as those of Mignonette, should, in order to ensure 'success^' be treated in this manner. Very, many of these, however, are usually sown under glass, and are consequently more" under command than out-of-doors. It is, however, necessary to exercise oare ' in the sowing of tender annual and other flower seeds under glass, inasmuch as many of them are so exceedingly small that they scarcely admit of any covering in the form of soil. Gloxinias, Begonias, Calceolarias, and many others belong to this class, and should, be sown in well-drained pots or seed-pans, in light soil, containing' a portion of silver sand, but the' surface should be made perfectly smooth and level, and should be moistened through the fine rose of a watering pot. On this surface 'the seeds should be sown, and pressed gently down ; and they should be covered \vith a portion of soil, more or less, according to the size of the seeds sown. 'Where they are very small a mere sprinkling of silver sand will be sufficient ;' 6v this may be omitted oltogether, and the surface of the pot or pan merely covered with a piece of glass, which should' be shaded with whitewash,. or have, a piece' of paper placed over it, and as soon as the seeds nave fairly germinated a little air should be admitted by raising ono side of the glass and gradually exposing the plants to the light ; or the surface of the pota or pans containing the Beeds may be covered with a thin layer " of damp moss, which must be removed as ths plants develop themselves. The .best structure, however, in which to sow the seeds ' of tender annual and other plants is a close frame or pit, as free as possible from drip, and in which there is a slight bottom-heat and an atmospheric temperature of from 60° to 75°. This should be covered with a mat or cloth so that light i 3 nearly or altogether excluded, and as the germination of the various kinds of seeds sown will not be simultaneous, each pot or pan should be removed as soon as the 'young plants make their appearance, and gradually inured to the light before etiolation or blanching takes place.

If a course similar to what has. here been attempted to describe be pursued, we should probably hear fewer complaints of the worthlessness of flower and garden seeda than we sometimes do. That the necessary conditions for their, healthy germination are not always understood is proved by the following . statement. A purchaser of a packbt of the herbaceous or large-flowered Calceolaria says :—": — " 1 sowed the seeds in a flower-pot, which: l placed in the warmest part of a sittingroom window, and watered it daily, and, for the sake of additional warmth,. I invariably placed the pot with its contents near the fire-place at night, and yet the Beed did not grow." The herbaceous Calceolaria has, by the practice of a careful system of selection,' arrived at a atato of great perfection, and a packet uf seed generally produces a varied assemblage of finely-formed and beautiful flowers that the practice of raising them annually from seed is usually followed, and the eld plants are discarded as soon as they are out of bloom. But although this plant is a native of Peru, the seeds are nevertheless, exceedingly impatient of heat, and refuse to germinate in a high temperature, and as the end of April or the early part of May is the best time at which to sow, the pot containing the seeds should be placed on the north side of a wall and covered with a hand-glass, or even if the pot be merely covered with a piece of glass, the seeds will generally germinate very freely. — P, Grieve, in the Garden.

We hear that Messrs Wright, Stephenson, and Co. have sold tho Clydesdale entire colt Black Champion, the property of Messrs Craig and Wylie, to Mr G. Kirkwood, of Auckland, for the Bum of 180 guineas.