Q.How And When To Water Large Potted Ferns
I have three large potted ferns which spend warm weather on a north-facing porch that gets lots of afternoon sun. (The spend the winter in a local nursery). Photo of one is attached. Can you please tell me how often they should be watered? I usually do it every 2 or 3 days, early in the day, by first dampening the leaves and then running lots of water directly into the pot until it starts to run out. Is this the right way? Thank you!
Certified GKH Gardening Expert
Yes, with the exception of watering on a schedule. You don't want to do this.
With watering, generally you want to wait until the soil is dry down to a certain depth.
This depth will be about 1/2 an inch to an inch with ferns in container. A little more in container with no drainage. (It looks like your type of container does not offer drainage, so if this is the case, I would measure down to about an inch or more)
Spray the plant often. They enjoy the humidity but will tolerate less than ideal moisture.
Some notes on watering in this type of container:
Over time, you may find that the soil starts to smell like sulfur. Sulfur-reducing bacteria will be to blame, and they will concentrate at the bottom of the container where water remains, constantly.
Should this happen, you will want to change the entire pot of soil. While you are at it, you may even place it into a plastic container with drainage, then inside of the large, decorative container. This way you can pull the inner pot out when watering and inspecting. This will allow you to, better, gauge when to water.
Here is an article to help you with fern care:
https://www.gardeningknowhow.com/houseplants/boston-fern/boston-fern-outdoors.htm