A while ago I rescued a couple of large cast iron plants (Aspidistra) from a dumpster. The largest pot is 38cm in internal diameter, about 30cm deep. Even that pot is probably a bit small for the plant - there are stems very close to the edge almost all the way around.

I'm struggling to know how much water to use, and even how to apply it.

Typically, with my smaller pots, I water until it runs out the drainage holes, presumably getting most of the soil moist. But I'm not sure how to do that for a plant this big - I'm guessing that would be several litres of water, which feels a bit ridiculous.

Similarly, the "add water when the top inch of soil is dry" doesn't seem like a great metric for such a big plant.

How do I approach watering here?

  • 1
    If there are no drainage holes ,add them . Other than bog plants very few plants will tolerate constant damp/wet. Commented Sep 24, 2020 at 1:59
  • There are drainage holes. Commented Sep 24, 2020 at 3:21
  • 1
    The volume of your pot is probably about 20 liters, so adding a few liters of water isn't ridiculous. One liter would be roughly the equivalent of 10 mm of rain, which isn't a huge amount to fall in a few hours.
    – alephzero
    Commented Sep 24, 2020 at 14:11

1 Answer 1


If you can't get water onto the soil because the growth is so tightly packed, it's probably time to risk dividing the plant. They prefer to be potbound, and the roots don't really like disturbance but at the size you describe, it sounds like it needs to be done, and spring is the best time to do it.

Make sure the soil is nice and damp and turn the plant out of its pot - inspect it carefully, looking for an area where you can break off or separate part or parts of the plant, then carefully pot those up and water in well. If it's not possible to separate parts of the plant by hand, I would use a bread knife, even though that is not recommended - if the segments are large enough (say if you split the plant in half or into three large segments), although some root damage is inevitable, there should be enough intact roots for the plant sections to recover and grow.

In the meantime, these plants like to dry out a bit between waterings, so I'm afraid the usual method still applies - test the soil to a depth of an inch and pour in a litre or three (or more) of water, and empty any outer tray or pot after 30 minutes so the plant is not left sitting in water. The trick is not to water too often, rather than giving insufficient water regularly. Further info here https://www.ourhouseplants.com/plants/aspidistra#:~:text=Low%20to%20Moderate%20Watering%20Once,every%20two%20or%20three%20months.

  • 1
    Ok, thank you. Not sure if it was just lucky guess that I'm in the southern hemisphere but it was nice that you didn't assume autumn :) (I actually potted it myself - had to separate off a few bits to get it to fit, but it sounds like I should have reduced it more). Commented Sep 24, 2020 at 23:46
  • 2
    I checked your profile for location before answering...good you had it in there, makes giving an answer easier.
    – Bamboo
    Commented Sep 25, 2020 at 10:40

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.