INSTRUCTIONS FOR FERNS
Some ferns have been around for millions of years! But even if they have survived for such a long time, they still need some fertilizer from time to time, just like almost all other plants. In general, ferns aren't that picky about what type of fertilizer they're given just as long as you don't water them with too much fertilizer (since that can burn the roots).
If the soil is wet - snooze this action, we will remind you again in 2 days.
SELECTING THE FERTILIZER
You can use any fertilizer suited for ferns or any balanced fertilizer suited for potted plants (some examples when it comes to NPK*: 10-10-10, 20-10-20, or 20-20-20). If possible you can also dilute it a bit more than suggested to protect the roots.
* NPK: Nitrogen (N), Phosphorus (P) and Potassium (K)
HOW TO FERTILIZE YOUR FERNS IN 5 STEPS
Mix the right amount of fertilizer with water according to the instructions on the package
Pour the solution over the soil
If possible, try to avoid getting the solution on the stems and leaves
Continue adding the solution to the pot until it starts to run out of the drainage holes in the bottom
After about 1 hour, check that the pot isn’t sitting in water - and if needed pour off excess water