Help! My bonsai is dropping leaves

My golden gate (ficus microcarpus) is dropping all of its leaves and other leaves still attached are very droopy. Some of the dropping leaves are a healthy green color, some dark, and some are light/yellowish. I water it regularly and just recently gave it a good soak plus some fertilizer. It gets indirect afternoon sun indoors. I bought it about a year ago. Any ideas?

 

It looks like all but the bottom most part of main stem is dead. The boundary appears to be somewhere behind the statue's head. I suggest easing the plant out of the container for an assessment of the condition of the roots. You should be able to determine whether the cause was from too little or too much moisture by doing so. Does the container have drainage holes? Is it possible too much fertilizer had been used?

 

I would urge caution about taking it out of the pot. That one looks like it does not fill up the pot with roots, so it likely won't come out clean, and repotting this time of year in that condition is could be a death sentence.

But I agree you need to get your watering perfected, fast. And tons more light and more humidity if possible. Is that the soil we're seeing or just a covering layer? If you've had it for about a year, then this is the toughest time for it, at the end of winter in a relatively dry house and probably much lower light than it had before you got it. The big black spots in those curled leaves looks like possibly overwatering in low light to me.

How often do you water it? To get the watering right, I would probe down with my finger about an inch when I think it is time to water, to make sure the top of the soil is drying out a little (not bone dry all the way thru).

For light, this is really what is killing it. It can drink up so much massively more water when it's getting enough light to grow happily. I would have it with at least a minimum of 3-4 hours a day direct sunlight, and preferably lots more. This is a full-sun outdoor tree. (see image below) It won't ever be happy in indirect light. I would say acclimate it to higher light slowly, but there's not much point to it now with the leaves gone, and you're in a rush before the thing dies.

So for emergency measures I would:
1) Move it up close to a sunnier window and maybe even add an additional LED light above it on a timer for extra light if you really care about this one.
2) Get your watering right asap. You have to know what it needs by actually checking, not guessing, until you become one with its roots.
3) Try to raise the humidity if you can. Maybe a large pebble tray where the water can never get to the plant's soil. Perhaps a shower occasionally to wash the dust off the leaves. There are several ways to raise the humidity in your whole house also.
4) Stop fertilizing until you get a few weeks of nice new growth.
I wish you success!

 

Yes it drains very well and didn’t have a problem until recently. I’m wondering if it doesn’t have enough nutrients from the soil. I bought it in from a plant store in the current pot 1 year ago. Is it time to replant it?

 

I wonder if the cause of the sudden downturn is due to the fertilizer, either too much or having fertilized while the soil was dry. I'm not sure what to suggest at this point.