four feet or more apart, and allow a space of three and a half feet for the more moderate growers.  Even then, with good land, in a high state of preparation, the shaws sometimes meet across the rows, and enormous crops are lifted.  For a very comprehensive rule, it may be said that the distance between the rows may vary from fifteen inches for the early sorts of dwarf growth, to forty inches for the vigorous-growing late sorts.  Between these measurements, for varieties producing medium haulm, a distance of twenty-six to thirty-six inches may be allowed on good ground.  The distance between the sets must in like manner be determined by the growth, and will range from nine inches for crops to be dug early, to sixteen or twenty inches for the robust kinds.  The medium maincrop Potatoes will generally do well at twelve inches apart.  Much, however, depends on the season, for when great space is allowed, and the season proves warm and showery, there will be more large tubers than the grower will care for; whereas, if planted somewhat closer, the crop would be smaller and more uniform in size.  When planted, the tops of the tubers should be about four inches below the surface.

==Time of Planting==.—­Under favourable conditions, it is possible to plant on a warm dry border as early as mid-February in very sheltered districts, but a supply of protecting material must be instantly available in the event of severe weather.  As a rule, however, the opening of March is soon enough to plant early crops out of doors, always provided that the soil is light and the situation warm, but where these conditions do not exist it will be safer to wait until the middle of the month.  Maincrops may be got in at the end of March and during April, according to the locality and the character of the soil.  In any case, it is better to defer the operation for a week or so than to plant in heavy wet ground which quickly consolidates, making it impervious to air and unsuitable for root-penetration.  Excellent crops may also be obtained by planting in July, preference being given to quick-growing early varieties.  Old tubers only should be used and these must be carefully stored until required for planting.

==Method of Planting.==—­On light soils, in a sufficiently dry condition, the dibber or planting stick may be used, but on heavy ground it is not satisfactory.  A good method of planting for all classes of soil is to draw out a V-shaped drill of the requisite depth, place the sets into position and lightly return the earth.  Another plan which is largely adopted is to insert the sets in the trenches as made during the operation of digging the ground in spring, a garden line being used to obtain the accurate alignment of the rows.