Can over fertilization or spraying leaves with liquid fertilization (12-4-8 or 4-6-7) cause leaf drop? Any advise appreciated.

sklbachris wrote:

Can over fertilization or spraying leaves with liquid fertilization (12-4-8 or 4-6-7) cause leaf drop? Any advise appreciated.

Short answer: yes.
I've lost a couple of trees using foliar fertilization, so I don't trust this technique for bonsai anymore.
The trees have dropped leaves, dried up and died.
As for overfertilization, specially with chemical (liquid) ferts, the answer is also yes.
They can cause root shock and the plant can die.
NEVER use a dosage higher than what is written on the label; at times, use it at half strength.

Thank you. Probably over fertilized as well. Can this tree be saved?

Give the plant a nice lukewarm shower. Then put it in a large tub of water for an hour. Every 5 minutes lift it out, let the water drain from the pot and gently place back. That way you wash the fertilizer out. Make sure you then let the pot drain well, and let the substrate dry well before watering again (Bot bonedry, but avoid keeping the substrate soaked).

I used a foliar leaf fertilizer. It had three results: Most of the deciduous trees had little response. Most of the weeds popping up grew tremendously. Two of three pines died.

Never again.