Q.Pruning apple trees
I have already blown it. planted 3 apple trees last year and just watered and fed them. Can I prune them back all the way (like several branches), so that I have a straight twig standing upright so that I can train branches? 2 of the trees are standard and 1 is the medium height tree. My soil is not very good and I fear that my trees will struggle with that. It is gumbo. We have fed them fruit tree fertilizer. Do I need to stake the little trees securely so that they are able to establish a secure root system? We live in South Dakota and I need to do the pruning soon before they want to bud if I understand that correctly.
Pruning generally takes place in March and April, so you are right on schedule.
Your soil may be an issue if it is not well draining.
It can be more difficult to deal with this when you have all ready planted.
I have listed several links for you to help you get started with care of your new trees.
https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/what-is-well-drained-garden-soil.htm
https://www.gardeningknowhow.com/edible/fruits/apples/apple-tree-planting.htm
https://www.gardeningknowhow.com/special/urban/growing-columnar-fruit-trees.htm
https://www.gardeningknowhow.com/edible/fruits/apples/apple-tree-feeding.htm
https://www.gardeningknowhow.com/edible/fruits/apples/pruning-apple-trees.htm