SIFTING. 



27 



I 



SINGLE TREES. 



Caraganas "were formerly considered 

 to belong to the genus Robinia. They 

 are all quite hardy, and will grow in 

 any common garden soil ; most of the 

 species prefer a poor gravel, but C. 

 arborescens thrives best in the neigh- 

 bourhood of water. The species are 

 propagated by layers or cuttings, or by 

 seeds, which they ripen in abundance. 



Sida. — Malvacece. — Stove, green- 

 house, and hardy plants, natives of 

 the East and West Indies, and North 

 America, with showy white, pink, or 

 yellow flowers, which they produce 

 in great abundance. They are grown 

 in loam and peat, and generally ripen 

 seeds ; by which, and by cuttings, 

 they are readily increased. 



Sideroxylon. — Sapotece. — Iron- 

 wood. Half-hardy and hardy shrubs, 

 and low trees, natives of America, 

 the East Indies, and the Cape of 

 Good Hope. Some of the species 

 have been removed to Bumelia, and 

 one species, a native of Morocco, 

 which is hardy in British gardens, is 

 now called Argania. All the kinds 

 should be grown in loam and peat ; 

 and they have all small white, or 

 whitish-green flowers. 



Side-saddle Flower. — See Sarra- 

 cenia. 



Sieves are necessary in gardening 

 to separate the stones and coarser 

 particles from the mould to be used 

 for potting, and also for cleaning seeds. 

 Garden sieves for mould should he 

 made with deep wooden rims, but for 

 seeds the wooden rim may be more 

 shallow : in both cases the wires, or 

 toile metallique, through which the 

 mould is to pass, should be firmly 

 attached to the rim, the holes or 

 interstices not being more than the 

 fourth of an inch in diameter. 



Sifting is the operation of passing 

 any kind of soil through a sieve or 

 screen to deprive it of its coarser 

 particles. Decayed leaves and rotten 

 dung are also sifted : as it is only the 



fine mould that falls from them that 

 is useful in vegetation. Sifting, how- 

 ever, should be used with caution ; 

 as some plants thrive better when the 

 particles of soil are not too fine. 

 Turfy loam, for example, should 

 generally be chopped small with a 

 spade or trowel, and not sifted ; and 

 peat should not be deprived of the 

 vegetable fibre in which it abounds, 

 Sifted earth when of a loamy nature, 

 is very apt to cake together and to be- 

 come impenetrable to the finer roots 

 of plants. 



Sile v ne\ — Silenacece or Caryo- 

 phyllaoea.— The Catchfly. Well 

 known annual and perennial plants, 

 many of which are natives of Britain, 

 with flowers something like those of 

 the pink. They are nearly all quite 

 hard)-, and only require the common 

 treatment of their respective kinds, 

 Lobel's Catchfly (S. Armeria) is a 

 common garden annual that requires 

 sowing in the open ground in March 

 or April. 



Silk tree. — Acacia julilrissina. 

 — See Acacta. 



Si'lphium. — Composites. — Peren- 

 nial plants, natives of NorthAmerica, 

 with yellow flowers, which are quite 

 hardy in British gardens, and will 

 grow in any garden soil. , i 



Simaru v ba. — Simarubiacece. — The 

 false Quassia. Stove plants with 

 showy flowers, natives of the West 

 'Indies, neaily allied to the Quassia. 



Single trees and single shrubs 

 are the grand sources of variety in a 

 lawn or park, where the surface is 

 flat and without any other resources ; 

 and they are also, when judiciously 

 disposed, valuable additions to a sur- 

 face naturally varied by undulations. 

 The great art in putting down single 

 trees is, to dispose them so as to form 

 groups, when seen fi^om a distance, 

 and yet so as to produce variety in 

 every change of position in the spec- 

 tator when near. The kinds of trees 



