wrote in message
ps.com...
On Oct 8, 7:51 pm, "David Hare-Scott" wrote:
wrote in message

ps.com...

I have some triple super phosphate i want to use around my
established fruit trees to help them harden off for the winter. There
aren't any application rates mentioned on the bag so i don't know how
much to use. Most fertilizer app. rates are calculated by using x
amount based on the diameter of the trunk measured about 2 feet above
the soil line,but not sure if this also applies to triple super
phosphate. I live in Southern Calif. where soils are on the alkaline
side. How much can i use w/o over doing it? Thanks.

What sort of fruit trees are they? What is your winter like? When will
that be? Can you explain how adding phosphate helps a fruit tree harden
for
winter?

David

I have citrus(oranges, lemon,several different mandarins, pummelos,
kaffir limes, bearss lime) cherimoya, persimmons, plums, apples,
jujubes. I would say i am in zone 9. We occasionally get into the 30's,
(December-February) but not often.

Sounds very much like my orchard and my climate, although it gets down
to -4C (23F if my sums are right) sometimes , except for being Southern
hemisphere.

Phosphate takes about 8 weeks to
work so i want to apply before the winter rains. From what i remember
from my soil and fertilizer class in college, phosphorus is
responsible for flower/fruit development,hastening maturity of the
plant, enhancing root development,and increasing cold hardiness.


My concern is that if your soil isn't P deficient it won't make much
difference but if it is you are encouraging growth as the season slows down.
Here those new shoots would be frost targets. If you don't get frosts why
attempt to harden the plants? My regime is to fertilise the fruit trees
spring and summer not autumn or winter.

David