Hm, that problem has two reasons:

1. The Maggy need 2-3 years to settle, so give them (in german "Hornspäne" = nutrition) and very much water. The big evergreen leafs need much water.
When the tree is settled (enough roots) for nutrient transport the leafs will stay 2-3 years.

2. sunny winters with frost

So cut some branches in the bottom area, but not all. Maggys will drive out even at old big branches. But don´t cut after end July. To young leafs aren´t hard enough for cold winter.

Greets