A complete fertilizer with all 12 minor elements is best. It costs more...but is best. Let the wife have her flowers under the trees. Every 2 or 3 waterings...give them a dilute water/fertilizer mix. If momma ain't happy...ain't nobody happy....

The fertalizers i have used in the past have been plant tone and holly tone.
What is the name/brand of the fertalizer you are referring to?

Thanks

With trees in large planters, the fine point of what to use for fertilizer is a minor problem. It is the mix you use that will cause most of the problem. Any mix will have to be replaced as the organic components disintegrate over time and exclude the needed oxygen, which will cause the roots to be unable to take up nutrients, even the best most complete available. Eventually even the best, longest lasting mix, will have to be replaced, and the roots pruned, a big job for a BIG container. I have just done two and have two more to go. By using the gritty mix this time, I will be able to double the time between repots. Al

The trees were planted a few years back using miricle grow potting mix. Without going through the process of removing the tree and pruning the roots and refilling with fresh mix, would it be advisable to just remove and replace the soil around the tree?

What do you consider to be the best mix to use and whats its usefull life expectancy? I had never thought of replacing the mix. I have had trees in planters for 5 years which still look good