50 PRUNING 



sap flows more freely to the wound, and heals it more quickly than when 

 the branch has been sawn close off. The fact is, many " tree-doctors " of 

 the present time have no more real understanding of their work than the 

 fifteenth-century practitioner on the human frame had of his. 



Dressing a Wound. The virtues of ordinary coal tar (as it comes 

 from the gas works) as a dressing for cut surfaces are not generally 

 known. All the raw places left by removing branches or stumps of 

 branches should be covered with this antiseptic substance, and the 

 coating should be renewed as often as is necessary till the wound is 

 covered with new bark. The best armour that a tree can have to protect 

 it against fungoid enemies is that with which Nature has provided it, 

 viz., its bark. But when accident has caused a flaw in the armour, the 

 most efficient substitute, in my experience, is coal tar. Stockholm tar, 

 creosote, and preparations of pitch are also used. The practice of 

 nailing lead or zinc over wounds is a mistaken one unless the surface 

 is tarred over first. It affords no genuine protection against fungoid 

 parasites, and hides whatever mischief may be going on underneath. 

 ' Pruning of Flowering Shrubs. As a general rule, evergreen 

 shrubs do not need pruning at all in a systematic way. Such plants 

 as rhododendrons, arbutuses, kalmias, and others of the heath family, 

 Berberis Darwinii and B. stenophylla. etc., if they need pruning at all, 

 require it only to improve or alter their shape, or to prevent their 

 becoming too large for their quarters. In such cases pruning should 

 be performed as soon as the flowering season is over. Sometimes ever- 

 green shrubs become thin and lanky in growth, and can only be brought 

 back to a sturdy vigour by pretty hard pruning. This should be done 

 in spring just before the recommencement of growth, so as to allow as 

 long a season as possible for them to become leafy again. This is all 

 the more necessary because one may have to cut back to oldish wood, 

 which does not break so freely. A season's flower must be sacrificed 

 unless the. plant is a very early flowering one. 



Autumn-flowering heaths, such as Calluna vulgaris, Erica Tetralix^ 

 E. vagans, E. a'/iaris, E. cinerea^ etc., are much improved by being cut 

 back in spring before new growth starts. This removes the old flowering 

 twigs of the previous season, and helps to keep the plants dwarf. It is the 

 more necessary because of the long, lank growth these heaths make in 

 garden soils, as compared with the hard, dense growth of the wild moor- 

 land plants. They should not be clipped back farther than the wood 

 of the previous season. 



Deciduous Shrubs. The pruning of this class of plants, where it 

 is necessary at all, has to be regulated in accordance with the flowering 

 season of each species. For the present purpose they may be roughly 

 divided into two groups, viz. : (i) Those that flower on the current 



