64 WEEDS OF FARM LAND 



down closely and rapidly exhausted. On the other hand, 

 grazing of common land by sheep alone may encourage 

 bracken, because if broom is present the sheep eat the 

 broom down closely and allow the bracken to flourish. Cattle, 

 however, keep the bracken under and allow broom to hold its' 

 own. On dry calcareous pastures where the herbage is short 

 and often weed-infested, geese are useful, as they graze very 

 closely and appreciate the weeds. Generally speaking, mixed 

 grazing is advisable where destruction of weeds is the aim, 

 the preferences of cattle and sheep being quite different, and a 

 more effective clearance is carried out when both agents are at 

 work. 



If hay fields are infested with large quantities of weeds 

 that seed freely, such as yellow rattle (Rhinanthus crista-galli] 

 early cutting of the hay crop is often useful as seeding is 

 thereby prevented. It is, however, necessary to repeat this 

 for two or three years in succession, for, though no fresh seeds 

 may be produced, there are large stores in the ground which 

 will come up in succeeding years and provide for the future if 

 they are not cut down. Early cutting also keeps down rank 

 weeds like wild chervil (Anthriscus sylvestris). 



The most usual, and probably the most effective way of 

 dealing with the chief weeds of grass-land, such as nettle, 

 thistle, and bracken, is judicious cutting at appropriate times. 

 All the worst pasture weeds have underground storehouses of 

 food, either stems or roots, and if the weeds are to be eradi- 

 cated it is necessary to cut when those storehouses are as 

 empty as possible, so exhausting the plants. Thistles can be 

 cleared by cutting three times in the season, beginning when 

 the plants are well grown but have not come into flower. If 

 they are cut in the first week in June and then twice in July 

 for a couple of years hardly any thistles will remain by the 

 third year. 1 



If three cuttings cannot be managed, a single cutting 

 about the middle of June will do much good. Old agri- 

 culturists 2 recommend that thistles should be mown just 

 before they blossom, leaving the stems about 4 inches high, 

 and that then a large, heavy wooden roller should be run over 

 the field so as to bruise the stalks thoroughly. The roller 

 should be passed over four times one way and twice across. 



1 " Destruction of Thistles" (1908), (1909). Reports of Field Experiments 

 at Harper Adams Agric. College. 



2 Hunter, A. (1803), " Georgical Essays," Vol. Ill, p. 203. 



