Hardening may also be caused by a number of other factors. In some cases the 
condition may have been induced by planting too early when the soil is too cold for 
normal growth. Some other factors which may cause this condition are: setting plants 
in the garden which have not been properly "hardened off" in cold frames, allowing 
the plants to dry out, excessive water, lack of cultivation, root injuries due to insects 
or fertilizers, as well as a number of others not so common. When growth has been 
normal the plant can cope with condifions which would cause a soft plant to suffer 
a check. 
Cultivate once or twice each week to a depth of five or six inches in the early 
part of the season. Right next to the plant cultivation should not be as deep or some 
of the roots are likely to be cut off or injured. When the plants are in bloom and the 
spaces between the plants are pretty well filled with foliage no further cultivation will 
be necessary. 
Water only in very dry weather. One thorough soaking is far better than several 
light sprinklings. Frequent watering brings the roots too near the surface where they 
are quickly injured by heat or draught. More water will be required after the plants 
start blooming than earlier in the season. 
Th ere are a number of elements in the soil which are needed for proper plant 
growth. Of these elements there are only three which are likely to be present in lesser 
amounts than needed by the plant. They are NITROGEN, PHOSPHORUS, and 
POTASH. In order to arrive at an intelligent fertilizer program we must understand 
the purpose of the above elements to the plant. 
NITROGEN is needed for bush growth, dark green foliage, and large flowers. 
Plants growing in soil which is lacking in nitrogen show a yellowish cast to the leaves, 
low growth, failure to develop buds properly, and small flowers of poor color. Too 
much of this element produces a tall growth, soft plants, delays blooming, weakens 
stems, and reduces the keeping qualities of the roots in winter storage. It will injure 
leaves and roots if applied directly, or too close, to them. The common sources of 
nitrogen are cover crops, dried blood, fish scraps, barnyard manures and commercial 
fertilizers. 
PHOSPHORUS is the most important from the dahlia grower's standpoint. It is 
essential in all plant functions. It hastens blooming, increases root development, stiffens 
the stems, increases the general vitality^ of the plant, and it overcomes the harmful 
effects of excessive nitrogen as well as certain other adverse soil conditions. Phosphorus 
is not harmful even when applied in excessive quantities. The common sources are: 
superphosphate, double superphosphate, and bone meal. The latter also contains a 
small amount of nitrogen. 
POTASH increases the general vigor of the plant, it is essential in the chemical 
changes occurring in the plant, and root formation is dependent upon its presence. 
The common sources are: muriate of potash, and sulphate of potash. Hardwood ashes 
are sometimes used as a source of potash but is not to be recommended owing to its 
variability in potassium (potash) content. 
To reduce the foregoing to a simple fertilizer program we suggest spading under 
an application of bone meal (steamed) at the rate of five or six pounds for each one 
hundred square feet in the garden. This may be done two or three weeks before 
planting time. The plant food element in bone meal is very slowly available and one 
application will last throughout the season. Potash may also be applied at this time 
at the rate of two or three pounds per one hundred square feet. Since bone meal 
also contains a small amount of nitrogen (3 to 4%) none will be required at this time. 
Nitrogen being a quickly available plant food it may be applied later in the season, 
or just when it will be of the greatest benefit. 
For increased size of blooms apply nitrogen just after the buds have formed. 
In this simple sample program we will use dried blood. Scatter it between the rows 
at least a foot from the base of the plant at the rate of about two pounds for each 
one hundred square feet. Cultivate it into the soil and water v/ell. This application 
may be repeated in three or four weeks, but no more than two applications should 
be given. Properly fertilized plants are less susceptible to attacks of disease and insects. 
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