84 MISSOURI BOTANICAL GARDEN BULLETIN 
except frequent stirring of the surface with a sharp-pointed 
rake. As the flowering season approaches, feeding with 
liquid cow manure should begin and should continue until 
the blooming’ season is over, after which all stimulation 
should cease. The liquid cow manure is conveniently pre- 
ared by adding about six pails of fresh cow manure to a 
Carvel of water (fifty gallons) and allowing the mixture to 
stand a day or two before using. If a half bushel of soot 
contained in a burlap bag is hung over night in the barrel 
of liquid manure, the beneficial properties of the fertilizer 
will greatly increased. About one-half gallon of this 
infusion should be used for each plant and the application 
may be repeated once a week. It is safe to say that this is 
one of the most efficient fertilizers for roses, and its con- 
tinued and careful use is partially responsible for the 
splendid showing made by the roses in the Garden. During 
July a light top dressing of finely crushed bone is also of 
advantage. 
Although it is generally believed that magnesium in 
excess is the most poisonous of all the plant nutrients or 
fertilizers, Tonk, as early as 1889, recommended a manure 
for roses containing sulphate of magnesium with, however, 
an excess of lime. Here the matter rested for twenty years. 
In 1909, Truffant noted the large proportion of magnesium 
found in the analysis of roses, and stated that soils deficient 
in this element produced but a weak growth of roses, but 
that the addition of magnesium salts brought about a 
marked increase of vigor and growth. The following year 
at the International Rose Conference, in Paris, the par- 
ticular value of magnesium for roses was one of the subjects 
for discussion. It was declared to be indispensable and it 
was stated that it should always be given in the form of 
sulphate in doses of about five ounces to the square yard. 
As the result of recent experiments at the Garden, and 
the experience of at least one practical rose grower of 
national reputation, it is believed that the following prac- 
tice is correct: Attention should be called to the fact 
that all roses do not react alike, and some varieties not 
yet tested may not respond satisfactorily or may even be 
slightly injured by the magnesium. One should, there- 
fore, proceed cautiously. If plants are to be watered with 
a solution, use nitrate of magnesium at the rate of one 
ounce to the gallon. This may be used once a week through 
the season, but if any ill effects are noted, the application 
should be discontinued. If the magnesium is to be applied 
dry, it is better to use finely powdered commercial carbonate 
of magnesium which contains a certain amount of lime. 
