Dear Group
I am in Los Angeles, and I have inherited a twenty-plus years old grapefruit tree, now in poor shape.
It was pampered in the beginning, lots of fruit etc, but was neglected for many years, so several main branches have died off.
Trying to bring it back, i first tried deep watering and fertiliser, with little effect. I then thought that perhaps the roots were now very shallow, so watered fertilised half the depth, and new growth started, some new shoots and leaves.
Come spring, we had hundreds, literally, of flowers, a few new leaves, and now the leaves are starting to fall off, and it's obvious the tree is still in trouble.
Am I wasting my time? Would i do better to put in a new tree as this one is in an irreversible mode? I intend to check soil ph, and a few other tests, if it's worth it, and also if the ph is okay, try some organic soil addititives.
you may feel I'm just being sentimental, but it was never the tree's fault it got like this, so i'm always hopeful 
Richard Medway in Los Angeles
After a stressful event, citruses tend to bloom excessively, it is like telling itself to reproduce before it dies. You have natural reaction from your tree, nothing to worry much. I would give it another chance. And most of your blooms would fall off, don't be alarmed.
I would prune off severral branches to remove about 1/3 of the canopy at this time.
I would also mulch the tree with cornmeal first layer (probably use 15 lbs cornmeal spread thinly around the dripline. Then mulch with composted redwood bark up to an inch around the drip line.
So how are you watering your tree? Several microsprayers with 270 degree spray pattern, midway between the trunk and the tree's outermost dripline would be the place to set them up.
When fertilizing, use ammonium sulfate, it is an acidifying type. You can mix 1-2 tbsp ammonium sulfate per gallon of water and spread it around the tree, and you can fertilize this way every week. At UCR, they water their trees along with the drip system at the rate of about 1 tbsp ammonium sulfate per gallon of water every time.
Give it a year with this treatment.
Idyllwild
simplepress
jafar
Marsha H
Viron
John S
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