Ferns, like other plants, must extract nutrients from their surroundings in order to grow and reproduce. Strong, fast growing ferns in particular will benefit from the careful application of fertiliser. Smaller, more delicate ferns must be treated more carefully.
It is preferable to apply fertiliser in a weaker solution more often. This makes it less likely that you will overdose your plants. However, if you do happen to give your plants too much, they have a better chance of recovering.
We recommend the use of Maxicrop seaweed plant food, applied at half strength to avoid any plant damage.
Inclusion of Osmocote or other slow release fertiliser in the soil may also be beneficial (be careful not to add too much!)
Ideally, plants should be repotted every six months or so to keep the soil fresh and the plant healthy.