SEEDS & THEIR REQUIREMENTS.

Hutt News, Volume 2, Issue 12, 15 August 1929, Page 3

SEEDS & THEIR REQUIREMENTS.

It is well known-that if seeds are placed under suitable conditions of heat, air, and moisture, germination soon takes place. The amount f heat necessarily ~ varies "according ~to Ihe kind, but the minimum lies at various points above 32 deg., and the maximum at not more than 115 deg., while the -optimum is from 60 to 90 deg. Below the minimum temperature germination will not take place; at the minimum it proceeds at a slow. pace, developing gradually until the optimum is reached. Then the germination decreases gradually until tie maximum is reached, at which point it stops altogether, and if the seed is moist, death quickly ensues.

Air is required in the germination of seeds, because it contains oxygen, which all plants require to perform the function of respiration. Moisture is indispensable to the growth of all seeds. In conjunction with heat and air it helps to bring about changes, chemical or otherwise, in the reserve food stored up with the young plant within the seed coat or testa. It also helps, the inorganic ferment (diastase) to convert starch (which is insoluble) into a kind of sugar that is soluble and can be absorbed by the little plant to build up new. tissue to develop its root, stem, etc.

Some seeds vegetate very quickly, those of the willow being known to germinate twlve hours after falling from the tree, while some species of Ash, Beech, and Maple are said not to germinate before the expiration of one and a half to two; years. The starchy and tiliii-skinned seeds quicken the most readily, whilst those which have a bony testa, such as the Hawthorn and Bose, are better buried in the grounrl

for a year.

If preserved from the action of air and damp, seeds will remain capable of germination fox"a considerable length of time, and from this point of view, vegetable seeds, as a general rule, may be grouped as follows: —

Two years—Beans, Carrot, Fvoneh Bean, Parsnip, Pea and Rhubarb.

Three years—Artichokes, Balm, G-xr-lic, Basil, Camomile, Capsicum, Cress, Hop, LavendeT, Leek, Lettuce, Nastuftium, Onion, Potato, Badish, Rue, Salsify, Seakale, Tansy, Thyme, Tomato, Wormwood. . J - ■ ■

Four years—Asparagus, Borage, Biof.coli, Caibbage, Cauliflower, Endive, Marjoram, Horse Radish, Mint, Mustard, Shallot, Spinach, Turnip.

Five years—Fennel,

Six years—'Bumet, Chervil, Hyssop, Parsley. .

Aibove six .years—Beet, Celery, Cucumber, G-ourd, Pumpkin, Melon, Sorrel, Vegetable Marrow.

Much of the quality and hence of the keeping properties of seeds, depends on their -having been fully ripened before gathering and subsequently kept free from damp. New seeds are, however, preferable to old.

The germinating capacity of seeds varies according to the species of plant from which they are" obtained, age of seed, and care exercised in gathering and storing them.

The collection and storing of "awn grown" seeds shoTild be encouraged among the children and by a study of seeds they should «be able to recognise and test them for any impurities. The germinating power of seeds may be tested iby sowing" them on blottingpaper, or by other methods in a homemade incuibator. ..',--

should also be made to grow them under different conditions

of temperature, and with much or little

water and air

In germination, as already, stated, heat, air and moisture are necessary £o all seed grwVth, although the need of these several conditions'is not the same in all eases, This is one reason why some seeds should be placed at a greater depth from the surface than others. Generally speaking, the larger the seeds the deeper they should be placed or buried in the soil.

Ht io, however, another factor operates. Very small seeds can only have a comparatively small supply of reserve food, and, if such a seed be buried too deeply, °11 the -reserve food would "become exhausted before the green s-hoot could' appear above the surface. Thus the plant Would perish before it reaches the light through inability to build up food for itself

Seeds should only, be .sown on a soil with a fine tilth. Many very small seeds such as- Petunia, Calceolaria and Begonia seeds are best sown on the surface of the soil in pots well drained by means of pots-herds. The soil should be of a sandy nature so as to enswre a free percolation of air and water through it. Fill the pots within an inch of the surface with soil, level, and make moderately firm, then apply water freely, using a fine rose can, so as to disturb the surface as littje as possible and avoid washing the seeds into masses, Allow the pots to drain for about an hour, t-hen sow the seeds thinly and cover the pots with a pane of glass or sheet of brown paper: (light is not necessary to seeds 'before they commence growth) to prevent undue evaporation. Such seeds germinate readily in a temperature of 50 to 70 deg. the highest temperature to be used for Begonias and the lowest for Calceolaries. Artificial means must be employed to ensure grmination for maney kinds, and a hotbed covered by a frame ansiwers the purpose admirably. Other seeds, such as the Bi-oad Bean, should be covered with two or three inches of «arth, according to the character of the soil.

Seeds may be sown deeper in sandysoil than in soil of a clayey nature. At the same time tie depth should be sufficient to protect the see is from drought. A fine day when there is little wind should also be selected for the sowing -of -seeds. Carrot., and other small and valuable seeds' should be mixed with an .equal quantity of sancl,

thus- allowing of a moTe even distribution of the seed. ''.-.'.

The season for sowing seeds differs so inucjh. that it is safe to say that gardeners in control of large establishments, sow seeds of one sort or another every week of the year, and during the spring season almost every day. Generally speaking, annuals, perennials, and most vegetable seeds are sown in the spring; biennials and tender vegetables in early summer.

The most natural period to sow seed is immediately.they are ripened. Many of our forest trees propagate in this way. Hard seeds, such as the Oanna, •germinate slowly, an - the process can be assisted by filing the outer coat caTefully. Such seeds as t-he Rose and Thorn, which have a hard, bony testa, should (be mixed with soil, placed in a box, and buried in the ' garden - for twelve or eighteen months prior to sawing;

When sowing in a temporary position in tiie garden or in a frame, tie seeds | may be distributed either broadcast or in drills. The drilling system is, perhaps, the best to adopt. It is because the seed bed can so easily be kept free from -weeds. - ,