How much sun and what type of soil? For a 15 year old tree, you should be getting fruit. What kind of fertilizer?

All day sun in a very hot area of SoCal. Using citrus spikes; all purpose G&B Organics, chicken manure sometimes. I am suspicious that the soil may not drain properly. It is too hot right now, but I will re-pot it with pumice and lots of perlite+vermiculite. Do you think it would help?

I would stop using spikes as the roots may get burned with all that fertilizer in one spot. I would take a hammer to it, crumble it up into as many small pieces as possible and then put it on top. Why do you think it doesn't drain properly?

I dug down with my bare hand about 12" and it was very moist, almost muddy. On top, it was completely dry and the leaves were burnt as we had 104-107 weather. It hit for 2-3 days in June and now it is the same temperature again. I just watched a video and a biologist promoted IV Organics, a white wash that evidently you can paint on the trunk of any tree or bush, and diluted, you can put in a spray bottle and spray the leaves too. It also has some natural pest deterrent in it too and it lasts 6 months. I can buy it at Home Depot. I only recently put the spikes. Before I just gave Miracle Grow or fish meal to the plant. It looks healthy, but the fruit just doesn't stay. Grhhh...

Suggest that you stop with the spikes and manure and try using a citrus fertilizer like vigoro or gropower... or even palm plus. Or a liquid food only.

Any chance you can move it to a spot that gets afternoon shade.... and plant in the ground? I have two of my VPEs in the ground and in spots that get 5-8 hours of sun... and late afternoon shade. They produce heavily.

Thank you for the advice. I'll follow your suggestion regarding the fertilizers. Unfortunately, I don't have open ground. All my 200+ plants, including 80 roses, are in pots. I have a sunshade sail over about 30 roses and they are relatively ok, but cannot move the lemon tree. Maybe I'll put an umbrella over it. :)