Weekend Work: Time to stop feeding cymbidiums

What to do

I have three pots of cymbidiums. All get the same treatment yet one is plastered with spikes of bloom, one is just earning its keep, while the third has no flowers at all. Why?

They are all potted in the same loose, bark-based compost that orchids seem to like and all spent their summer outside in a sunny place between June-October.

I've been feeding them, as I was advised to do, with a half-strength feed three weeks out of four. Between March-June they got a high nitrogen feed, then nothing during the summer (except occasional water), then a high potash feed (Tomorite) during Sept-Oct to encourage flowering spikes. From November to March, any balanced feed (roughly equal quantities of N, P and K) will do.

If a cymbidium is producing healthy leaves but no flowers (like our number three), the general view is that it's getting fed too much. So I'll keep it watered, but avoid feeding it for three or four months. I'm also going to start noting how many flower spikes each plant has each year. It may be, with plants as with people, that some are more generous than others.

What to see

The Oxford Botanic Garden's winter lecture series starts this week with a talk by Bob Flowerdew (what a perfect name!) on Thurs at 8pm. Tickets cost £10. To book, call 01865 286690 or visit botanic-garden.ox.ac.uk.