I have an old orange tree in northern Florida, about 20 year old I
guess, that has been doing badly since last summer. The problem is
that the tree is experiencing lots of leaf drop. The leaves become
yellow before they drop. I see no obvious signs of pests, such as
discoloration. The tree is trying to put out new shoots, but those
leaves yellow and fall before too long. The extremities of many of
the longer branches are now dead, and I fear that the whole tree is
The tree is mulched with pine needles, as it has been for years. A
few years ago, the tree was very robust, with lots of growth and a
bumper crop of fruit. I believe a former neighbor applied
fertilizer. The tree still has some fruit, but no blooms this spring.
It has been dry this spring, and I have been watering about 1 - 2
times per week. The tree handled dry spells before without any
Does anyone have any ideas? I would hate to lose this tree.
I would suspect foot rot. Lose the mulch and stop the extra watering.
Prognosis not good but copper fungicide as a drench might help. A call to
the local extension service is advisable.
HTH -_- how
no NEWS is good
It might be a lack of nutrients. Citrus trees are heavy feeders. They
need an acidic mix of nitrogen, iron, and zinc. Use a commercial citrus
food; Bandini has it in sacks as small as 5 lbb. However, most citrus
food does not contain zinc; you might have to special-order a small sack
of zinc sulfate.
Mix about 2 cups of citrus food with 1/4 cup zinc sulfate. (Or mix
about 1-1/2 cup ammonium sulfate, 1/2 cup iron sulfate, and 1/4 cup zinc
sulfate.) With the soil already moist (never feed when the soil is
dry), broadcast this in the root zone, leaving an area 2 ft in radius
from the trunk unfed. Sprinkle to start disolving the fertilizer.
If the tree perks up, repeat this feeding monthly during the growing
season. If frost is ever a risk in your area, stop feeding about one
month before the expected first date of frost; resume feeding in the
spring as soon as new growth starts.
David E. Ross
Climate: California Mediterranean
As far as feeders. There are two types of organisms. Autotrophs make their
own food. Heterotrophs have to have it made for them. Orange trees are
autotrophs. We cannot provide them with food. They actually manufacture
food for heterotrophs. What we can do is fertilize which is adding
essential elements. The tree absorbs essential elements often from the
non-woody absorbing roots which are in the upper 4 inches of soil. When I
say elements I mean the 17 essential (known) elements such as iron,
magnesium, and so on. That and other elements can be found on the Periodic
Table Of Elements. A chart can be found here. http://www.webelements.com /
As far as feeding autotrophs, we just do not do that.
John A. Keslick, Jr.
Beware of so-called tree experts who do not understand tree biology.
Storms, fires, floods, earthquakes, and volcanic eruptions keep reminding us
that we are not the boss.
I would sure get a moisture meter and stop watering if it shows the soil is
saturated. If you want a good water meter,
the kind used by orchardists, buy a tensionmeter (www.irrometer.com)...they come
in different lengths but in general
read further down into the soil than the cheapo moisture meters. I have to tell
you I had the same problem as you, but
with young orange trees, during the very hot summer last year. I kept watering
without checking the soil moisture. The
trees just got worse instead of better. Eventually I figured it out and stopped
watering. Now just this month two of
my newest orange trees, 2 months in the ground, were looking very droopy. I had
been watching the 12" irrometer I had
bought, it was reading 30 and I had read not to water until it read 60-70. But
it was located just outside of the
dripline and a cheapo moisture meter pushed in close to the tree trunk showed
half dry levels. So I gave the trees a
good watering and they started perking up next day, and within two days they
were visibly perked up (new growth no
longer drooping) and the leaves no longer curling (longitudinal curling). It
took 3-4 days for the water to reach the
irrometer sensor, 12 inches down and 24 inches from the trunk...then it's
reading went to 0. So now I have a standard
for these small trees (2 ft-3ft high dwarf Washington Navel and Oro Blanco
Grapefruit) . Next time the reading gets to
30, if the trees look un-perky, droopy, or leaves curling, I'll know to water.
By the way, a week later and the
reading is still at 0 and the soil still feels moist. I almost killed my other
young oranges last summer, not to
mention apple trees, so I won't water until I see the correct reading.
Another thing to do, read this article about using hydrogen peroxide in
horticulture, especially the part about
supplying oxygen to soil that is saturated with water. That might be a
temporary fix for the problem.
Hope some of this helps.
HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.