You will hear
all types of theories and philosophies on
how to fertilize
roses. This is a plant that
has a lot of very devoted amateur growers
and each one will have their own little
secrets. However, remember that, just like
every other plant in the world, roses
require a certain basic level of
nutrients
in order to grow and flower properly.
So, submit a
soil test periodically to determine the
level of nutrients in your beds. Reputable
soil labs such as those at your land grant
university will have research based
recommendations for the type and amount of
nutrients needed to keep your roses (and
you) happy.
In the
absence of a soil test, you can make two or
three applications of a balanced i.e.
12-12-12, fertilizer during the growing
season. An equivalent amount of nutrients
could also be applied using an organic
source such as a
composted manure product.
Generally,
the roses will need fertilizer when the new
growth appears in the spring, again about 6
weeks later and a final application about 6
weeks later. In
temperate zones, you should
stop fertilizer applications around early to
mid-August.
Fertilizers, especially
nitrogen, applied later will trigger new,
lush green growth that may not have time to
harden off before the first frost.
Keep an eye
on the plants and, as long as the leaves are
dark green and the flowers are being
produced, everything should be just fine. If
the leaves are yellowing, check to determine
the cause. It could be an alkaline
pH,
aphids, virus or droughty conditions. If
those are not present, then it is probably
caused by lack of nitrogen. Another
possibility is low magnesium which is a part
of the green
chlorophyll molecule. People
sometimes apply epsom salts which contain
magnesium to overcome this problem.
Again, have
your soil tested and it should help you
answer all your fertilizer need questions.
