I have a four year old orange tree which has flowered and fruited nicely in
my greenhouse until this past summer, when it started losing leaves and
suffering some branch dieback. There is no evidence of insects or fungus.
The only difference in its care was that I had someone else watering it for
me (weekly). Could overwatering explain these symptoms? Should I try
cutting it back? Presently it is leafless and seemingly dea... er, dormant.
Thanks in advance-
Polly

Polly --

Leaf loss and branch dieback are indicators of root-rot. This is usually
caused by overwatering. (Once weekly is fine, so long as the tree needs
water once a week. Watering can and should vary with weather conditions,
soil mix, age of the tree, etc.)
You might want to consider repotting the tree -- removing any rotted roots
when you do -- in a soil mixture that promotes quick drainage. Prune below
the dead part of the branches. Keep the tree outside in partial sun for as
long as possible.

Good luck.

"Polly Spaulding" wrote in message
t...
I have a four year old orange tree which has flowered and fruited nicely
in
my greenhouse until this past summer, when it started losing leaves and
suffering some branch dieback. There is no evidence of insects or fungus.
The only difference in its care was that I had someone else watering it
for
me (weekly). Could overwatering explain these symptoms? Should I try
cutting it back? Presently it is leafless and seemingly dea... er,
dormant.
Thanks in advance-
Polly

Polly Spaulding wrote:

I have a four year old orange tree which has flowered and fruited nicely in
my greenhouse until this past summer, when it started losing leaves and
suffering some branch dieback. There is no evidence of insects or fungus.
The only difference in its care was that I had someone else watering it for
me (weekly). Could overwatering explain these symptoms? Should I try
cutting it back? Presently it is leafless and seemingly dea... er, dormant.
Thanks in advance-
Polly

I assume that, since your orange is in a greenhouse, it is in a
container.

Overwatering can damage citrus. With a good potting mix, however,
that should not be a problem. See my
http://www.rossde.com/garden/garden_potting_mix.html. Citrus in
a container can also suffer easily from too little water,
especially during hot weather. This do-it-yourself mix keeps
moisture available to roots until the mix is almost bone dry.

Don't give up hope yet. I had a dwarf lemon apparently die from
frost 10 years ago. About three years later, it produced some 60
full-size lemons on a tree that is only 3' from soil to top. (I
just looked out the window and saw two ripe lemons and a few that
are starting to turn yellow.) This year, I thought I lost my
dwarf kumquat. While my wife and I were traveling for more than
three weeks, a power failure stopped our automatic sprinklers for
a cycle during 100+ temperatures. Several plants around it were
also dead. While we will get no kumquats this year, the little
bush is now in full leaf.

Carefully check twigs and small branches. Scratch them slightly
with a fingernail. If they show green, it's still alive. If
there is no green, check closer to the trunk. If even the trunk
shows no green, it's gone. Otherwise, just wait. If the tree is
still alive, it will resprout. Repot it now, omitting all
nutrients from my mix recipe except bone meal. (The other
nutrients are not good for roots that are recovering from too much
or too little water. Bone meal added later will not leach into
the root zone.) After new growth appears, remove all sprouts
below the bud union (graft point), cut away dead wood, and feed.

--
David E. Ross
Climate: California Mediterranean
Sunset Zone: 19 -- interior Santa Monica Mountains with some ocean
influence (USDA 10a)
Gardening pages at http://www.rossde.com/garden/