I posted this in Good Housekeeping a couple of days ago, got no response and was advised to repost here...
I'm looking after my neighbour's bonsai tree for six weeks or so as she'll be away frequently and is having a lot of work done on her house. It's a very special wee tree, she got it for a significant birthday some time ago.
I've had it for two weeks so far, and the leaves are going yellow from the bottom up, and dropping off. I did forget to water it for the first whole week (I'm rubbish with plants!), then I overcompensated for a few days, it was at this point the yellowing started. Since then I stopped watering it again (spoke to neighbour and mentioned yellowing, she thought maybe too much water - I didn't admit to forgetting watering it at first) but the yellowing is getting worse since I cut back on water and it's lost lots more leaves.
It's on a South facing windowsill, so getting light but not direct sunlight.
Anyone know what's going on and how to fix it? Thanks