My fern plant is growing upwardly out of the pot. It looks like a cone...
My fern plant is growing upwardly out of the pot. It looks like a cone growing upward with new growth coming out of the cone. It also hasn't been re-potted for at least ten years. When I re-pot, do I bury the lower section of the cone?
Dakota County Minnesota dividing houseplants
Your fern has probably outgrown its pot and so the new growth has nowhere to go but up. The 'cone' is the new growth. Once the plant is divided, that 'cone' will disappear. It would be best to repot and probably divide it. You do not state the variety of fern so I am guessing it is a Boston Fern. That is the most common indoor fern. If you only want to report the fern but not divide it, remove the plant from its current pot and carefully loosen up the root mass and remove as much of the old soil as possible. The roots will have become ingrown over time, and you will want them to be able to reach out into the new soil so you will want to take a very sharp knife and make 3-4, top to bottom vertical slices, about ½" deep, into the sides of the tangled root ball. This will allow a sufficient number of roots to begin growing outward again to support the needs of your fern while it recovers. You will undoubtedly do some damage to the roots, but don't worry about it, just do your best.
You will want to use a larger pot which will also be a bit deeper. Put enough good commercial potting soil into the bottom of the pot so that when you put the plant in, the original soil level will be about an inch below the rim of the pot. Clip off all of the dead fronds from the plant and put it into the new pot, then add more potting soil to the sides, watering liberally to move the soil down into the root structure.
Keep adding soil until the pot is filled to within an inch of the pot rim. The important things to remember are that you want to use good, sterile soil, and to eliminate all of the air pockets around the roots. You will probably lose some more fronds before you are done, because of shock and root damage, but just trim them off, and the plant will recover on its own. If you would prefer to divide the plant, which probably is your best option, you basically follow the same procedure. You can either cut the root ball vertically with a sharp butcher knife in half or quarters, or you can use your hands and separate the roots.
Cutting with the knife is easier and will do considerably less root damage.