Hi. i think I over-fertilized my draceana marginata. I added NPK fertilizer, and a few days later most of its leaves turned yellow (most leaves are still slightly greenish, which I hope is good). What can I do to undo the over-fertilization, if that's what it is. Thanks :)
If you can see the fertilizer bits, you can remove it, scraping off the soil too. If it's a liquid and was too much, you'll have to remove a lot of soil and repot in a regular potting soil without added fertilizer. You might also want to drench the remaining soil with water, allowing it to run through the roots and drain out the bottom.
Thanks thanrose :) Any chance of the yellowed leaves returning green again? or do they all have to be replaced by new growth if all goes well?
No, I don't think your yellow leaves will recover. I could be wrong, but they are most likely damaged because the roots have been burned enough to be unable to support the leaves, so they suicided in a manner of speaking. Sometimes, if partly yellow leaves are because of insufficient nutrients, they'll recover.