Q.I planted 4 dwarf alberta spruce trees 6 weeks ago. While each looks robust on the outside with good green needles, the needles on
the interior of each tree are browning and dropping. Is this normal? I watered daily for 10 days and now water 3 times per week.

Certified GKH Gardening Expert
This may be normal needle shedding. Here's an article about that:
https://www.gardeningknowhow.com/ornamental/trees/tgen/why-conifers-drop-needles.htm
Also, the transplant shock probably contributed to the needle loss. Make sure your trees are in full sun and change the watering to a deep watering once a week till established. They may be getting too much water, also leading to brown needles and leaf loss.
https://www.gardeningknowhow.com/ornamental/trees/pine/pine-tree-browning.htm