288 Encyclopaedia of Gardening 



Snapdragon. See Antirrhinum. 



Sneezewort, Achillea Ptarmica. 



Snowball Tree, Viburnum opulus sterile. 



Snowdrop. See Bulbs and Galanthus. 



Snowdrop Tree, Halesia tetraptera. 



Snowdrop Windflower, Anemone sylvestris. 



Snowflake. See Bulbs and Leucojum. 



Snow Glory (Chionodoxa) . See Bulbs. 



Snow-in-summer. See Cerastium. 



Snow-on-the-mountain. See Arabis. 



Soapwort. See Saponaria. 



Sobralia (sobra-lia, after Sefior Sobral. Ord. Orchidaceae). 

 Terrestrial Orchids of tall growth, easy to manage in a hothouse. 

 They have thick roots, but no pseudo-bulbs. Loam and fibrous 

 peat in equal parts, with charcoal and sand, form a suitable com- 

 post. Propagation is by division when growth starts. They will 

 require water all the year round, but more in summer than in winter. 

 Macrantha, purple, white, and yellow, 4 to 6 ft., flowering in summer, 

 is the best species; there are several varieties of it, of which albida, 

 Schroder's variety, and splendens may be named. There are also 

 several hybrids. 



Soil. The soil we deal with in our gardens is the detritus of rocks 

 mingled with particles of decayed vegetation, such as leaves. It 

 varies greatly, in some districts being heavy and tenacious, in 

 others light and loose. We have stiff, dark soils which we call clay, 

 tenacious yellow soil called marl, sand and stones mixed under the 

 name of gravel, reddish or brownish fibrous soil called loam, and 

 white, soft rock called chalk. It would hardly be within our scope 

 to describe at length the geographical changes which have disin- 

 tegrated' rocks and accumulated gritty particles; our business is to 

 deal with soil as we find it. The proper management of the soil,' 

 both with respect to tillage and manuring, is vital to success in 

 gardening. It is important to raise the heat of the soil, and the 

 first step to secure that end is drainage and aeration. In gardens 

 above sea-level, and on ground with a natural fall for the water 

 which comes from the clouds and soaks into the soil, there is natural 

 drainage, especially if the soil be loam, gravel, chalk, or sand. If, 

 however, the ground is so situated that there is no outlet, and is 

 stiff, it is advisable to drain it artificially. This is effected by laying 

 2-in. earthenware pipes in trenches 3 ft. deep and 1 5 to 20 ft. apart, 

 closer or wider according as the soil is very or moderately heavy. 

 The pipes should converge on a main drain with an outlet at some 

 selected spot. Aeration is facilitated by drainage, as stagnant 

 moisture cannot lie near the surface of drained soil. It is carried 

 further by crumbling the ground to the level of the drains, and this 

 is effected by removing the top spit and breaking up the under spit, 

 . incorporating at the same time mortar rubbish, road scrapings, coal 

 ashes, and any vegetable refuse available. Heavy, cold, damp soil 

 which is treated in this way soon becomes warmer, drier, and more 



