190 The Principles of Fruit-growing. 



leguminous, comprising those plants which take only 

 such nitrogen as has already been worked over into 

 available form by plants or animals; the other class is 

 the leguminous plants, comprising those which have 

 the power of appropriating and utilizing free nitrogen. 

 For purposes of cover and protection, the non- legu- 

 minous crops may be just as good as the nitrogen- 

 gatherers, and when the fruit plants are growing 

 very vigorously they may be decidedly better than the 

 others because, by not adding nitrogen, they do not 

 over -stimulate the growth. A rotation of cover crops 

 will nearly always be found to be important. It is 

 perfectly possible to put so much nitrogen into the 

 land that the trees or plants grow too vigorously 

 or too late in the season. This may be especially 

 apparent upon peaches, apricots, grapes, and the 

 like. It should also be said that some of the most 

 useful of these cover crops will not thrive upon hard 

 and intractable land, and in such cases a rougher 

 and coarser crop must be used. 



The golden scale of cover crops for orchards be- 

 gins with rye and ends with crimson clover. Lands 

 which are very sandy and leachy, as well as those 

 which are hard and lumpy, are usually not adapted to 

 the growth of crimson clover, especially in the north. 

 Such lands must be gradually ameliorated by the use 

 of other plants, and, as a rule, the best plant to 

 begin with is rye. This plant thrives upon a great 

 variety of soils, it demands little preparation of the 

 land, the seeds are large and germinate at a low tem- 

 perature, it can be sown late in the season after 





