I'm growing some apple trees from seed and started this year. I'm worried that the width of their stems (or trunks, but they're too small to really call them "trunks") is too small in proportion to their size. This leads me to wonder how big a tree can grow in one year, with an emphasis on its first year, and what is necessary to make them grow the most.
To recap, my questions:
- How much bigger around does a tree normally grow over the course of a year? Specifically its first year?
- What leads trees to grow bigger around? Nutrients, hormones?
- How should a tree be treated to promote the most outward trunk growth?