376 HORTICULTUKAL MANUAL. 



succession of garden crops. As instances, onions and tur- 

 nips if grown two years or more on the same soil are sub- 

 ject to insect iujury / and the potato, beet, onion, melon, 

 and sweet corn are more liable to scab, rust, smut, and 

 other fungous troubles than they are when systematically 

 rotated -annually. 



Some of our methodic farmers include a crop of cow-peas, 

 field peas, or other legumes in the system of rotation as a 

 part of the garden management to give fresh soil well stocked 

 with humus and nitrogen for melons, squashes, and potatoes. 

 With this plan and the growing of garden peas, sweet peas, 

 and beans the whole surface can be rotated with nitrogen- 

 producing crops at least once in three years. 



384. Fall Plowing. There are many advantages in 

 clearing off and plowing the vegetable-garden in autumn 

 in all parts of the Union, but specially in the prairie States. 

 The fining of the soil by winter frosts is a great gain in the 

 North, and the action of the frost seems to be fatal to the 

 destructive cutworms when rolled by the plow from their 

 winter quarters. In the prairie States the different cut- 

 worms are often so numerous on ground not plowed in the 

 fall that it is difficult to save a tomato, strawberry, or other 

 plant set out in the spring. But on fall plowing we rarely 

 find traces of their mischief. 



With a light surface cultivation prior to planting the 

 moisture is retained below while the surface is mellow and 

 in fine condition for seed covering or transplanting. Even 

 where the soil is quite heavy and inclined to be lumpy 

 when spring plowed, the exposure of fall plowing to the 

 frosts, rains, and snow melting of winter fines it for spring 

 culture, and the particles are ready to deliver up their plant- 

 food for the use of growing plants. If not fall plowed, the 

 spring plowing should not be as deep and it should be per- 

 formed as early as possible. Deep spring plowing leaves 



