384 ON THE SILVER ALDER AS A NURSE-PLANT TO OAK. 



in a cold climate, either alone or mingled with larch, to which 

 in the Tyrol it is often a near neighbour. 



And in the cold, north-eastern parts of Britain, where 

 coppices are now confined to sheltered river-banks and ravines, 

 it would be quite practicable to form excellent coppice in the 

 open country, by means of Ash and Silver Alder in equal pro- 

 portions. Its advantage over other trees as a nurse for oak, 

 consists in these properties— it grows rapidly while young, yet 

 is well clothed with lower branches, has a narrow conical head, 

 and does not lose its balance from the wind. Next, it ceases to 

 grow taller just in time to let the oaks gradually take the lead 

 and rise above it. This occurs at a height of 25 or 35 feet ; and 

 when it is cut out, the ground is not left unoccupied, for the 

 offsets are there to form underwood immediately. 



The average height of alnus incana, 20 years planted, 

 in strong loam, 400 feet above the sea, in a stormy part of 

 Northumberland, is from 25 to 35 feet, and they are remarkably 

 stiff and robust against the wind. They wilfnot now advance 

 further in height. 



Their favourite ground is land of any quality, whether strong 

 or light, upon which the aira cmspitosa, or common bull-front, 

 grows in strong hassocks : — a cool and moist climate, rather than 

 peculiarity of soil, being most essential to them. They have been 

 tried with perfect success on ground where Scotch firs and larches 

 had been felled, and which, though dry, was full of bull-front 

 hassocks, so that, as nurses, where resinous trees ought not again 

 to be selected, they may come to be well worthy of attention in 

 company with the birch and mountain sorb. 



On superior soils, adapted to the oak, it will always grow 

 vigorously as a nurse up to 30 feet, whatever be the grasses that 

 clothe the surface ; and, mingled with the birch, will be found to 

 correct the too rapid upward growth of nurse-plants above the 

 height of 30 feet, hitherto so injurious in all our oak plantations. 



One caution I would add for the safety of young plants 

 procured from the nurseries. These are often tall, weak, and 

 drawn up (in close beds) to a height of four feet, with slender 

 and naked stems, and you are told that they are the only plants 

 to be got. "When this is the case give them a year in your 

 garden or nursery, in any cool, half-shaded corner, to acquire 

 thickness, which they very quickly do. But if you decide to 

 plant them out at once, then smear them well with a mixture of 

 soot and cow-dung, to keep off hares and rabbits for the first and 

 second seasons, or you may lose them all. 



If the plants be only two or three feet high, and strong and 

 bushy, they will be in no more danger than young birches. 

 Nevertheless, as they are scarce in the nurseries, and not easily 

 replaced if lost, it will be well to take precautions. The offshoots 



