how to plant blue spruce trees from field to containers

Question

They’re 2′-3′ tall and planted in my nursery. Now I want to dig and put them in containers.

Answer 1

Just dig up the root ball with as much of the soil as possible and put it in a large enough container to accommodate the roots (likely 2- to 5-gallon pots). Mix in some well-draining potting soil and ensure that the container also provides adequate drainage. The following articles should also help: https://www.gardeningknowhow.com/special/containers/how-to-grow-container-trees.htm
https://www.gardeningknowhow.com/ornamental/trees/tgen/growing-trees-in-containers.htm