166 FRENCH MARKET-GARDENING 



makes them swell earlier, and gives a greater purity 

 and crispness to the hearts. The tying is done when 

 the plants have made three-fourths of their growth, 

 and the material used may be raffia or rye grass. If 

 steeped in water for about twenty minutes the tying 

 material becomes more pliable and is more easily 

 handled, even by experts. 



Diseases and Pests. Lettuces under intensive culti- 

 vation are subject to attacks from numerous pests and 

 diseases. Amongst the most common insect pests are 

 aphides, or green fly, which attack the plants at the 

 " collar " the point where the leaves and roots join. 

 The Cock-chafer Grub (Melolontha vulgaris) preys upon 

 the roots. The soil should be searched as soon as the 

 leaves of a plant are seen to droop, and very often 

 the grub will be found at the base. Wireworms (Elater 

 lineatus] and other grubs also play havoc with the 

 plants in the open air, and can only be kept in check 

 by the use of traps made of pieces of potato or carrot, 

 which should be examined frequently. 



Mildew (Peronospora gangliformis) the " meunier " 

 or miller of the French gardener is one of the worst 

 pests amongst early Lettuces, and where it is antici- 

 pated, the young plants, and also the surrounding soil, 

 should be sprinkled with flowers of sulphur. A weak 

 solution of sulphate of copper has also been found 

 useful as a preventive by watering the soil after sowing 

 the seeds, or before planting out the seedlings. The 

 same remedy applies to the rust fungus that also attacks 

 Lettuces. About i Ib. sulphate of copper to 100 pints 

 of water makes a good solution. Where young 

 Lettuces are attacked with mildew, the wisest course 

 to adopt is to lift the plants carefully and burn them, 



