Question
I have what I just identified on another garden site as a Croton, a with bright yellow orange and green leaves.  It is in a relatively shallow glass bowl filled with dirt, on a pedestal, for decoration in my office.  It is losing leaves from the bottom, they get yellow, soft, and fall off.  I water it regularly and thought I was overwatering, but I just took it apart and planted another one in the bowl with bottom leaves, and the dirt was pretty dry.  Am I overwatering or under?
I also have a large plant with round, veined, dark green leaves, that loses its leaves along the stem -- I now have long vines with only leaves at the ends.  Overwatering or under?  Many brown leaves have fallen off, but I thought I might be drowning it, alternating with dehydrating it.  It is fairly warm in my apt (we have no control over radiator).  I have a real problem telling how frequently and how much to water.  Thank you for your help.

Answer
Hi Suzaan,

Crotons are very demanding houseplants. They must be right in front of a very sunny window (south or west facing) where they can get lots of direct sunlight. Without lots of light, they drop off their older leaves and replace them with smaller, mostly all-green leaves.

In addition, Crotons often drop leaves in response to a change in their environment. So even if you have great light, there may still be an adjustment period of several months.

Crotons do not tolerate dryness, but they can't be kept soaking wet all the time either. As soon as the surface of the soil feels dry to the touch, then it is time to water thoroughly (until some water trickles through the drainage holes).

Now that may be yet another problem. You mentioned that yours is in a glass bowl. That probably means that there are no drainage holes. If so, there is no way to know how much water to add. If extra water accumulates in the bottom, that will cause the roots to rot. In addition, over a period of time excess minerals and gases will accumulate in the soil because they cannot escape through the bottom. If the container does not have drainage holes, then you really should replant your Croton into a small pot that does.

Crotons are very prone to spider mites, which look like tiny dust particles in the undersides of leaves. The spider mites will damage the leaves and cause leaves to drop. Spider mites breed like crazy in warm, dry air.

So now you have about five reasons why your Croton may be dropping leaves and why I said that they are very demanding plants!

I cannot tell from your description what your other plant is. If you want to e-mail a photo to me at the address below my name, I can ID it for you. It's loss of leaves could be inadequate light or improper watering, but I can't advise you on either until I know what plant species you have.

Please let me know if any of this is unclear or if you have any additional questions.

Regards,
Will Creed, Interior Landscaper
Horticultural Help, NYC

You can E-mail me directly at: [email protected]

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