[Cindy]

Something tells me you’re right.

Good pruning and keeping weeds and debris away from the trees might be your secret.

[Prophet in the wilderness]

There is landscaping material that you can use to keep weeds away.... land scaping professionals use it before they lay down mulch and plants.
You put this material down over the dirt, and you can cut holes in it and put the plants in the holes, water still gets to the plants, but, mostly keeps the weeds away. I heard you can keep bugs away with boric acid.