http://www.plant-care.com/aspidistra-elatior-cast-iron-plant.html

Your Cast Iron Plant (Aspidistra elator) prefers its soil to be kept damp...don't let it dry out.
Its given the name it has because it has a strong constitution. It puts up with less.
Soil that is kept damp then follows through with it needing higher humidity. Depending on the conditions the room it is in has, you can help the plant by raising the humidity level and put up a barrier to things that might change its environment.

Things such as how air currents from doors, windows, corridors from other rooms, or how the furnace comes on and directs air onto the plant.
Such can cause major headaches....for you, and the plant.
Too, air temperature around the plant can contribute to its overall health. Plants like nighttime temperatures to be cooler than during the daylight hours.
The range of coolness 60 degrees to 65 can be thought of as ideal.
Keep your fertilizing generally to twice a year...spring and summer. On store shelves, they have many such fertilizers expressly for houseplants. Be careful about what numbers are expressed in the make-up of any fertilizer you give.
I'm sure you understand the 3 main elements...N-Nitrogen,
P-Phosphurus and K-Potassium (or potash) and what they do for a plant.
Too much or too little of any or all, can detrimentally affect that old plant.

As long as the plant is doing fine by you, then there is no need to repot. If you do, do not go up any more than one size...that is generally more than diameter of an inch or two at any one time. Let the plant be accustomed to the new surroundings and how much more soil is feeding it.

As long as the soil drains well, and you don't let the plant sit in such drainage, then it will continue to do well under your care.

You might look back on further articles, in here and other forums, and on the internet, about water---and its effects on plants.
I only mention this because the water, and other factors, the plant received by your grandparents, is or may be, decidedly different than how your water is in its form.
Very old plants, with very old soil, can be thought to have salts build-up which, if you read the many articles on this subject, can affect badly a plant.
Your plant, right now, is not suffering any reduced health and so any thought about such build-up can be, should be, understood, but not be of concern.

I'm using it under a very large tree. I love the plant and I love knowing it came from the house I grew up in.

I don't see any problem w/ reviving an old post to which one wishes to add relevant comment. How nice to hear they've done so well for you. I only recently met this plant last summer on a neighbor's terrace.

Any chance you might share some pix?

While at a local nursery, I found some and was so glad to have found some but then I got looking at it closely and realized that it was the unknown plant I had growing all over my yard. I had dug a bunch of it up a couple of years ago so I could spread it out, planted it everywhere I could think of and still had a huge amount left over.

It got left in a bucket with no soil for about a year and was still doing well. The bucket was in the shade though. All the plants in the sun died and some that I would think was in the shade is showing signs of too much sun.

I am totally going to bring some into the house.

In my opinion, correcting the bad location is more important than thinking they don't like change.

Even cast iron plants have factors that limit growth considerably. Temperature, low light levels, improper watering, high salt levels in the soil, are all factors that have the potential to markedly limit growth.

I would be thinking about bare-rooting and dividing the rhizomes - getting the plant into a soil that drains very well and making sure the plant has good light exposure and favorable temperatures.

I'm saying this in a kindly way - I wouldn't be afraid of repotting it, I would be afraid of NOT repotting it. Even though this isn't the best time to be repotting, it sounds as though drastic measures might need to be taken. What is your feeling about where you would expect the plant to be in terms of its viability come June? Do you think it will still be living, or are you looking at a plant that is telling you its demise is imminent?

Al

Mum told me they like to be slightly potbound, and they also appreciate a drink of tea )no milk or sugar!) every now and then. I do get problems of leaves going brown but I usually cut them off.

Give it a cuppa every so often and you might leave it to your g-granchildren!

Did you read post right above yours?

I used to do the tea thing too. You may feel differently after reading this discussion.