The hardy annuals may be sown in the open ground during the latter part of March or beginning of April, as the season may determine, for the weather should be dry and open, and the soil in a free-working condition before sowing is attempted. In favourable situations and seasons some of the very hardiest, as _Silene pendula_, Saponaria, Nemophila, Gilia, &c., may be sown in September or October, and transplanted to the beds or borders for very early spring flowering. Those sown in spring begin to flower about June. The plants, if left to flower where they are sown, should be thinned out while young, to give them space for proper development. It is from having ample room that pricked out transplanted seedlings often make the finest plants. The soil should be rich and light.
The half-hardy series are best sown in pots or pans under glass in mild heat, in order to accelerate germination. Those of them which are in danger of becoming leggy should be speedily removed to a cooler frame and placed near the glass, the young plants being pricked off into fresh soil, in other pots or pans or boxes, as may seem best in each case. All the plants must be hardened off gradually during the month of April, and may generally be planted out some time in May, earlier or later according to the season.
The class of tender annuals, being chiefly grown for greenhouse decoration, should be treated much the same as soft-wooded plants, being sown in spring, and grown on rapidly in brisk heat, near the glass, and finally hardened off to stand in the greenhouse when in flower.
We add a select list of some of the more distinct annuals desirable for general cultivation as decorative plants for the open air:--
_Acroclinium roseum_: half-hardy, 1 ft., rose-pink or white; everlasting.
_Agrostis pulchella_: hardy, 6 in.; a most graceful grass for bouquets.
_Amberboa moschata atropurpurea_ (Sweet Sultan): hardy, 1½ ft., purple: musk-scented.
_Antirrhinum majus_ (Snapdragon): hardy, 6 in. to 2 ft., white, yellow and red. This plant is perennial, but is best treated as an annual.
_Arnebia cornuta_: hardy, 1½ to 2 ft. yellow.
_Bartonia aurea_: hardy, 2 ft., golden yellow; showy and free.
_Brachycome iberidifolia_: half-hardy, 1 ft., blue or white with dark disk.