it improves its mechanical condition and sponginess or water-holding
quality. Thoroughly rotted horse manure or horse and cow manure mixed is
by far the best. Cow manure alone, or pig manure, is lumpy and cold,
and hen, sheep, pigeon or other special manures are not safe in the
hands of the beginner, as they are one-sided, being especially rich in
nitrogen and likely either to burn the plants or to cause too soft and
watery growth.

This brings us to the point where it is necessary to say a few words
about the theory of manures, for they are not all alike and what would
be wise to give a plant under some circumstances under others would be
quite wrong, just as you would not think of feeding beefsteak to a baby
just recovering from the colic, while it might be a very good thing for
a hungry man who was going to saw up your wood-pile.

Plants of all sorts--in pots, in the garden or in a ten-acre
lot--require three kinds of food elements: nitrogen, phosphoric acid and
potash. These elements may be fed to the plants in various forms; for
instance, the nitrogen in hen manure, or in cottonseed meal, or in salts
from the nitrate fields of Chile, known as nitrate of soda; the
phosphoric acid from bone, or from acid phosphate (a ground rock treated
with acid); the potash from wood ashes or from German potash salts
(muriate or sulphate of potash). Plants, to do their best, require that
all three elements shall be present in sufficient amounts to supply
their wants.

It is not necessary, however, to go very deeply into the science of
plant foods in order to grow plants successfully. Fortunately, manure
rotted as described above, furnishes all three elements in about the
right proportions. Cow, sheep, hen and pigeon manure are best used as
described later, under "Liquid Manuring."

FERTILIZERS

There are many brands of mixed fertilizers prepared specially for use in
the greenhouse or on plants in pots. There is a temptation to use these
on account of their convenient compact form, and because they are more
agreeable to handle. As a general rule, however, much better results
will be obtained by relying on rotted manure.

If you want to use fertilizers at all--and for certain purposes they
will be very valuable--I would advise restricting the list to the
following pure materials which are not mixed, and which are always
uniform; nitrate of soda, cottonseed meal, pure fine ground bone, and
wood ashes. (Several of the other