Don't fertilize when you re-pot for 2 reasons:
- Most potting soil comes with a built in supply of fertilizer so you will be adding fertilizer to soil with fertilizer already in it.
- When plants are first repotted, they need time to recover from the stress so don't need added stress.
I would never use the tree spikes as they provide an overdose of fertilizer in one spot and none in other spots.
