Question
Is it a good idea to use coffee grounds (mixed with dirt) as fertilizer for fruiting trees ... e.g. citrus, apple, apricot, and fig trees?
Thanks.

Answer
Used Coffee Grounds are superb for amending Soil in almost any situation.  Even plants that prefer alkaline Soil can benefit from the Nitrogen-charged crushed Coffee Beans -- besides N, they also yield Phosphorus and Potash along with trace minerals.  You can avoid mold by drying them in the oven before scattering; mixing them with Soil may also reduce mold.

Bear in mind that non-composted Beans straight out of the pot decompose in the Soil.  That alone consumes Nitrogen for a limited period.  Either Compost them first OR resist applying thick doses at once, to give the microbes population a chance to grow.

Earthworms, which produce another fabulous fertilizer, are apparently attracted to Coffee Grounds.  Slugs are repeled by Coffee, although your Trees most likely are not troubled by Slugs.

Don't forget to include unfinished glasses of Orange and Grapefruit Juice, skins of Orange, Grapefruit and Bananas, and Eggshells in your Citrus Tree Breakfast Menus.  A balanced diet is good for everyone.

Thanks for your question.