168 



THE BOOK OF CHOICE FERNS. 



a peculiarly beautiful and noble, tropical appearance by their singular contrast 

 with hardy exotic as well as with native ornamental trees, with which they 

 may then be surrounded. All the known Dicksonias of arborescent habit 

 are robust growers, and their usually straight trunks possess the advantage 

 of being generally of good proportions and of symmetrical habit ; they also 

 are of a much more fibrous nature than those of most other Tree Ferns, 

 thus storing up a much greater quantity of moisture, and retaining it for 

 a longer period fit for the natural and essential requirements of growth, 

 and at the same time necessitating less attention and less labour than 

 Cyatheas and Alsophilas. Whilst in the last-named genera stems of all 

 dimensions, even down to that of an ordinary walking-stick, may be seen, the 

 trunks of all arborescent Dicksonias are of moderate thickness. The species 

 composing this genus also produce much handsomer heads of foliage than most 

 other Tree Ferns, and, as a rule, the quantity of fronds is proportionate to the 

 bulk of the trunk. It is not at all rare to find stems of good dimensions 

 producing every year from thirty to forty fronds, which they generally retain 

 until the following set is perfectly developed and matured, provided they do 

 not suffer from want of water at the roots or on the stems during the winter 

 season ; for, although then at rest, the fronds will soon shrivel up if the trunks 

 are allowed to get dry. 



When Dicksonias are grown in pots, it is indispensable that water should 

 be applied^ freely to their roots all the year round, or they will show the efi'ects 

 of a day's neglect in an unmistakable way, and a very long time will 

 elapse before they recover the damage done during that short time. The 

 plants are all the more likely to suffer from want of water when grown 

 in pots, as these should be of the smallest size possible consistent with the 

 dimensions of the trunks. As a rule, when not planted out, all Tree Ferns 

 thrive best in pots or tubs in which only three or four inches of soil all 

 round the trunks is allowed. The most suitable compost is a mixtiu-e of 

 two 23arts fibrous peat, one j^^^'t fibrous loam, and one part coarse silver 

 sand. However good their growth may be when cultivated in pots, it cannot 

 equal their vigour when grown in the open ground, in which case the 

 bottom must be particularly well drained ; for although these plants require 

 a constant supply of water, their roots soon decay when stagnancy is allowed. 

 To produce luxuriant and lasting foliage, Dicksonias should during the summer 



