On Apr 13, 2:26*pm, "john east" wrote:
Have an orchid in the bathroom south facing window sill and it's in flower
and seems happy. But out of the three leaves the top two look healthy, but
the lower one has shrivelled up and gone yellow. * Is that likely to be too
much water, not enough; or something else?

I'm tempted to say Yes

You don't say how long you have had it.or what sort it is. A picture
would help.
1. Being on a south facing window sill the plant could be getting
cooked on a sunny day. Orchids don't like full sun
2. Mine on an east facing window get watered around every 2 or 3 weeks
if it's not hot, in summer once a week, I stand them in tepid water up
to the pot rims for around 20 mins then let them drain. You could also
give then a daily spray with one of those small "Laundry" sprays.
3. Leaves don't go on for ever, but normally as the older ones go over
you will have new ones forming, you don't say if there is any sign of
new growth.
David @ the sunny, and rain free end of Swansea Bay