Sorry, what's a sail plant? Google doesn't seem to know! If nobody else recognises it can you add a photo to your question?

Never heard of this either, do you have another name for it, in particular, the proper, Latin name - its probably in your houseplant book

Thank you very much for your replies. I also hadn't know it as a sail plant but in my houseplant book that was what they called it. I had always know it as a Peace Lily. Joan

Hi, this is a Spathiphyllum wallisii, have you had it in the same pot for the 6 years, if so it probably needs repotting into a larger pot, with john innes number 2, with some horticultural grit mixed in, they can be watered freely when they're in growth, but less water in winter, Derek.

Sounds as though you are doing everything right - mine hasn't been repotted for years and is really pot bound but still flowers happily with just the occasional feed. Have you had it in a sunny place instead of a north window?

If repotting doesn't work you could try splitting it as a last resort only, if it looks as though its dying, but they don't much like disturbance.

Not sure about that, Steragram - my houseplant book says this plant should be split every 3 or 4 years, or when its too pot bound. I cut mine in half with a breadknife after 3 years, both halves did just fine. Best done in spring though.

OK Bamboo, that bit about not liking disturbance was what I'd been told - I haven't tried it as it was my mothers plant and I didn't want to risk it after keeping it going for 20 years. I guess I'll reluctantly have to do it soon though as its got too big for the windowsill.