Q.Newly planted Mugo Pines
We just planted three small, compact Mugo Dwarfs and they are already showing dead needles all along the base. Here’s some details:
• We live in SC and have clay soil.
• They are planted on a slight hill.
• We used soil conditioner and evergreen soil (with fertilizer for evergreens) to fill the hole.
• We dug a wide hole, deep enough for loosening and back-filling soil. Loosened root ball and covered around the plant with mulch, but not touching the base.
• Planted about 1/4-1/2 inch above soil line.
• Watered for about 30 seconds 3 out of 5 mornings after planting.
Pic attached…what did we do wrong and can we save these?
From the description of your informed planting process and due diligence it sounds like you did nothing wrong. The drying/dying needles in the lower foliar canopy may be simply from shading and natural senescence/shedding of lower growth as the new growth at the top develops. I wouldn't worry about the browning of the lowest needles. What counts is does the new growth at the top look green and growing and not wilting and drying up.
From the second photo, most of the top growth looks great. Only the tip in front appears wilted, or maybe just tweaked in handling. If that's all that appears compromised then you don't have anything to worry about at this time in my opinion.