VEGETABLE HUMUS 229 



sharp sand. Many rock-garden shrubs like a sandy mixture 

 of loam and peat or peat and leaf-soil. 



Peat contains a high percentage of water, so that it is 

 important to allow an interval of some weeks for it to dry. 

 It must be used with great discretion in the mixed border, 

 as many flowering plants dislike it. The dried peat briquets 

 cut for fuel are no good for the garden. 



There is a way of treating peat by which a valuable 

 vegetable manure is formed. It must be well broken up 

 and lime and bone-meal added. I have not space to give 

 the details here, but those interested should refer to the 

 Gardeners' Magazine, February igth, 1916, page 85, where 

 I dealt with the method of working at some length. 



A word must be said here of Bacterised Peat which 

 is now being sold in large enough quantities to justify its 

 being included as a form of vegetable humus. Up to 

 the present the results of its use have been variable. 

 Experiments have not given sufficiently good results to 

 warrant its being used extensively as a manure. Careful 

 trials of it by people all over the country will show its true 

 value ; it is a subject for much future experimental work. 



Road Scrapings or Sweepings : Now that the roads 

 are tarred or " salt- sprayed," many gardeners are dubious 

 of using road scrapings or sweepings for their gardens, 

 so perhaps my own experience with these materials may 

 be useful. 



Road scrapings or sweepings from country lanes and 

 roads un tarred and undressed with " salt," are the best to 

 use, but of course they are not now so easily obtainable. 



Those from roads sprayed with "salt" (calcium chloride) 

 are not only good for lightening soils, but have a stimulat- 

 ing effect if put round each plant, or scattered on the 

 garden in the summer, and hoed and watered in. 



Road sweepings from tarred roads cannot contain very 

 much tar, even assuming that it is injurious to plants, but 

 to test this point I made some experiments a few years ago 

 with fine asphalt, which contains a great deal of fresh tar. 

 I dug this in freely on a plot of land in the winter of 1913, 



