On Tue, 09 Oct 2007 08:32:39 -0700, "
wrote:

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. 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.


I'm also in So. Cal.

The commercial citrus growers around here don't add anything beyond
urea to the soil. I spoke with a county Ag guy about fertilizer some
time ago, he said that if he were asked to show a site with inadequate
phosphate that he would not have any idea where to find one. Check
the phone directory for the county advisor, you can get some localized
information from them.