lizers. Commercial vegetable growers use anywhere from 10-100 
tons of manure per acre, the amount generally used being 20-30 
tons. For the small garden from 300 to 500 pounds for a plot 
containing 400 square feet, or spread on the surface from one to 
three inches thick will be suitable. If manured in the fall in this 
manner a dressing of 6-8 pounds of “complete” commercial fer- 
tilizer analysing about 4% nitrogen, 8 % phosphoric acid, and 8 % 
potash, obtainable from most seedsmen, could be applied to 
advantage in the spring (though not absolutely necessary) as a 
surface dressing; raking it in so as to mix it thoroughly with the 
top soil. If the commercial fertilizer is deficient in potash, as is 
generally the case at the present time, the lack can be made up 
by the addition of 10-20 pounds of unleached hardwood ashes. 
It often happens that it is not convenient in city gardens to 
maintain the supply of humus by the use of barnyard or stable 
manure. In these circumstances the growing of a cover crop* to 
provide green manure is a convenient method of supplying 
humus. Another source of supply open to city dwellers is the 
collection of the leaves of street trees when they drop in the 
autumn. These should be piled in an out-of-the-way corner of 
the garden and mixed with the soil when they are one or two 
years old. Decay may be hastened by forking over the leaves 
two or three times during the summer. Garden refuse of all 
kinds, such as lawn clippings, the leaves and stems of vegetables 
and flowers, may be treated in the same way. This latter method 
sometimes has the disadvantage of returning to the soil the 
spores of disease organisms that may be present, thus providing 
a source of infection for future crops. 
When humus is supplied in the form of green manures or leaves 
the amount of “complete” commercial fertilizer used should be 
greater— from 12-18 pounds, analysing 4% nitrogen, 8 % phos- 
phoric acid, and 8 % potash to 400 square feet. 
Chicken manure, which is sometimes available, is one of the 
most concentrated of the organic fertilizers. It can be used to 
good advantage to supplement a dressing of barnyard manure, 
at the rate of 20 pounds to 400 square feet. As the plant foods it 
contains are quickly available, it should be applied in fhe spring 
as a surface dressing, thoroughly mixing it with the soil. If 
this fertilizer is available in a sufficient quantity to warrant its 
being used as a base for a complete fertilizer it should be used 
at the rate of 40-50 pounds to 400 square feet, supplemented by 
6-8 pounds of acid phosphate and 6-8 pounds of unleached hard- 
wood ashes. The chicken manure must not be mixed with the 
other ingredients before application, or loss of nitrogen will 
result. Chicken manure, previous to use, should always be 
stored under cover to prevent leaching. A good method, which 
*See Brooklyn Botanic Garden Leaflets Ser.V. No. 11. 
