GARDENING TERMS EXPLAINED 517 



properly done,, the effect is to check further wood production, and to 

 cause the trees to create fruit spurs instead. Root-pruning is usually 

 performed by opening trenches at moderate distances from the trees 

 sufficiently wide and deep to enable all roots large ones especially 

 that may be found, to be severed neatly. Downward roots may be 

 found by digging beneath the ball of soil. 



Runners. Through the agency of runners several useful garden 

 plants are propagated, but none have more value than those of the 

 Strawberry, as runners form practically their sole means of propagation. 

 Trailing shoots break from the plants even whilst fruit is being formed, 

 and on the points tiny plants are formed. These soon get root-hold of 

 the soil, and from these go out another long shoot, and a second, and 

 sometimes a third or fourth plant is thus created. Violets can be 

 increased in the same way by runners, although these do not root so 

 readily in the soil as Strawberries. One of the Saxifrages called 

 " Mother of Thousands " throws out many such runners. Ivies on the 

 ground will increase and spread through a somewhat similar agency; so 

 also will some troublesome weeds. In the case of such plants as the 

 Strawberry runners are a blessing, but in others are garden pests. 



Shading. There are times when many plants that generally seem 

 able to endure any amount of warmth require shading. Thus it is 

 common practice where Orchids and plants that delight in heat are 

 grown to shade the houses they are in during the heat of the day in 

 summer. Plants in an ordinary greenhouse also need shelter from the 

 sun during portions of the day. Cuttings, or newly-planted things of 

 any description, often need some temporary shading, if given only with 

 newspapers. House shading is best furnished by blinds made of some 

 woollen material, such as Tiffany, attached to wood rollers fixed to the 

 ridge of the house, and which can be drawn up or down when neces- 

 sary. This enables the gardener to remove shading quickly when the 

 weather is cloudy. Some shade their glasshouses in summer by coat- 

 ing the glass with a thin solution of milk and blue. It does very well 

 for Ferns, but often makes the house too dark in cloudy weather. 



Silver Sand. This term is applied to white, sharp, or gritty sand 

 containing no clay or adhesive properties. Coloured sands are usually 

 composed of a certain proportion of clay, and after being damped, 

 become hard or baked whilst drying. All such sands should be care- 

 fully avoided. Florists who supply potting sand invariably obtain a 

 pure white gritty sand. Sometimes ordinary road grit may be used in 

 potting composts or for rooting cuttings in place of sand. For such a 

 purpose the best is that formed in gulleys or road drains after a heavy 

 rainfall, as the residue has the clay invariably found in road sand 

 washed out of it. Where common road sand has to be used, put 

 some in a bucket, nearly fill it with water, and stir well to loosen the 

 clay particles, which are lighter than the grit is ; then pour off the 

 water. Repeat the process several times, and the residue when dry 

 will be found a clean sharp grit. 



Span-roof. There are few houses erected of wood or iron and 



