It is said again, that the stone wall offers little chance for weeds, but to those who have been accustomed to observe about a yard on either side of a wall constantly left unploughed and uncleaned, stone walls will be considered as nurseries and protectors of weeds, and those, too, of a highly mischievous character, as couch thistles, docks, &c. With regard to the couch grass (_Triticum repens_), we have traced it running from this source for a couple of yards into the ploughed field, with the inevitable consequence that in the furrows it is cut into convenient lengths to multiply the pest; and it has been on this account that we have ever been careful to direct dragging and harrowing to be done in the direction of the walls, before proceeding with these operations over the rest of the field, and we recommend the cutting down of weeds under these walls before a crop of corn be carried. CHAPTER XXXIII. ON THE PLANTS FOR “LIVE” FENCES. The native plants which have been employed for living fences include most of our indigenous trees and shrubs, with some few which, if not native, have yet been for a long time naturalised throughout Great Britain. The most important of these will be found in the following list:— { Oak } { Beech } Forest trees usually forming Group 1. { Hornbeam } fences by means of undergrowth { Ash } from lopping and { Elm } cutting. { Maple } { Whitethorn } { Blackthorn } Trees and shrubs forming fences Group 2. { Crab } by reason of a thick-growth { Buckthorn } and repellant thorns and spines. { Holly } { Nut } { Privet } Shrubs which for the most part Group 3. { Dogwood } fill up badly-grown fences. { Spearwood } These are really weeds in { Guelder Rose } good hedges. { Elder } In the first group, it may be remarked, that oak, ash, and elm are seldom, if ever, planted for hedges; for in the first place these plants are usually too expensive, and in the next they are not esteemed as hedge plants. They mostly find their way in the fence by seeds being sown by the wind, as is often the case with ash-keys, or they may start up a bush of underwood after being cut down as hedge-row timber; in either case they are very unsightly in appearance, and far from good in hedges. Trees should not be grown in hedge-rows where the fence is to be perfect, as these overshadow the best hedge-plants, and the sides of the boles always offer weak places.