Fertilizing Ferns

Most plants can benefit from fertilizing and ferns are no exception. Typically, most perennial ferns will survive without fertilizing as this plant gets its nourishment from decaying leaves and other organic matter in the soil. A healthy fern can benefit from a layer of compost applied in the spring.


Another option would be a light application of a slow release fertilizer in the spring. Choose one or the other as ferns are sensitive to over fertilizing. It is best to avoid heavy doses of fertilizers. 

How to Fertilize Ferns

Ferns prefer a slightly acidic to neutral soil that is well draining. Soil with a pH of 4 to 7 is good for ferns. Typically, most average garden soils will have a pH ranging from 6 to 7. If you are not sure of the pH level in your landscape area, you can test the soil by purchasing a soil pH testing probe at your local garden center. 

Using compost mulch or mixing compost into the soil may be all the feeding that your fern needs. If you choose to apply fertilizer, use it sparingly and at the lowest rate suggested on the label. A light, slow release fertilizer is recommended. If you notice that the tip of the leaves have turned brown or have died, this is a sign of too much fertilizer. Try increasing the watering to help flush out the excess fertilizer. 

Best Time To Fertilize Ferns

Ferns do not need a lot of fertilizer, especially if you have nourished the soil with compost. Garden ferns should be fertilized annually in the spring. Outdoor container ferns can be fertilized in the spring and once again midsummer if the plant looks unhealthy. Avoid fertilizing in the fall, as it can be more harmful than helpful. 


Best Fertilizer For Ferns

Typically, ferns can get all the nutrients it needs from the soil. If you decide to add some fertilizer, make sure it is a slow release variety. A 10-10-10 well balanced fertilizer is plenty of nourishment for the plant. It is best to avoid fertilizers higher than 15-15-15, as too much fertilizer can do more harm than good. Miracle Grow can be used on ferns. Follow the packaged instructions closely and apply according to the size of your plant. 

Fern Fertilizing Tips

  • Slightly acidic to neutral soil is best
  • Organic matter in the soil is enough food.
  • Fertilize annually in the spring. 
  • Use a slow release balanced fertilizer. 


-Always wear protective gloves and a face mask when handling chemical fertilizers.

-Closely follow all directions and storage guidelines that are on the fertilizer label.

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Author Chris Link - Published 11-17-2021