342 TRANSACTIONS OF ROYAL SCOTTISH ARBORICULTURAL SOCIETY. 



Soil, Situation, and Exposure. — Professor Macoun, botanist to 

 the Geological and Natural History Survey of Canada, tells me 

 that he has always found the largest specimens of this tree in 

 damp alluvial deposits; indeed, that it is almost unknown in the 

 dry central plateau, but plentiful along the coast and rivers, as 

 well as in the great mountain valleys. Judging from its growth 

 on an estate in this country where it has been planted by the 

 hundred, and under vai'ying circumstances as regards soil and 

 situation, we should say that a deep and dampish sandy loam 

 best suits the Giant Arbor- Vitse, although we have seen it doing 

 well and forming timber rapidly on decayed vegetable refuse, 

 rocky slate debris, gravelly loam, loam of a plastic clayey nature, 

 and well-drained peat bog. In each case, however, abundance of 

 moisture was present in the soil — not stagnant, but sufficient to 

 keep the soil in a dampish condiiion, and prevent it becoming 

 dust-dry even in the hottest and driest of summers. We measured 

 recently several specimens of this tree, which were planted twenty- 

 five years ago in a deep, rich, sandy loam resting on gravel, with 

 a deep surface layer of decayed vegetable matter, and found the 

 average annual upward growth to be 2 feet 8 inches ; whereas 

 others, planted at the same time on a fairly rich but rather dry 

 gravelly loam, had made hardly 2 feet. Of twenty-four trees 

 measured, the average annual growth was found to be 22 inches; 

 but no special cai'e, either in the planting of the trees or choice 

 of soil, had been bestowed on them. On reclaimed bog the upward 

 growth of the tree is surprising, several specimens having formed 

 a leading shoot of fully 37 inches annually. The bog, previous 

 to draining and reclaiming, was used for peat-making, but at the 

 time of planting a small quantity of soil was added to the pits in 

 which the Thuja was placed. As an expeiiment, we some yeai'S 

 ago formed a small plantation of this tree in a well-sheltered piece 

 of ground near the sea-level, and about two miles inland ; but as 

 the soil was of a stiff and cold nature, though perfectly drained, 

 the plants did not at first succeed as well as could have been 

 desired. Now, however, that they have established themselves, 

 growth has become rapid — far more so than temporary trees which 

 were mixed with them, to be removed at an early date. The soil 

 was of a half-clayey and half-boggy nature, which, previous to 

 being drained, cut like cheese, but when exposed to the atmosphere 

 for a length of time, crumljled down, and was then well fitted for 

 plant growth. 



