In article , Malcolm
writes

You will often see recommendations to keep plants in pots or situations
where roots are restricted, for example. This is because it causes them to
fruit or flower better. A lot of people recommend such treatment for fig
trees, for example.

That's not quite the same, though, is it? We were discussing the
production of flowers and fruit by wild-living trees, shrubs, etc., not
the artificial conditions forced on them by gardeners who have
discovered that if you restrict root growth you also restrict overall
growth.

I think the point with the fig is that in the wild it may grow in fairly
scruffy ground - stony, dry, perhaps not much root run - in which case
it produces quite a lot of fruit, or it may grow in fertile ground, in
which case it puts on a lot of lush leafy growth and not so much fruit.

Nasturtiums are similar - in fertile ground they produce masses of leafy
growth and fewer flowers - it's not just that the flowers are hidden by
the bigger leaves, there are fewer flowers than if they are grown on dry
ground.

Lettuces and radishes will grow vegetatively while there is plenty of
water around, but water limitation encourages them to bolt - ie to
produce flowers and seed.

Eucharis - a handsome aspidistra-like plant with white daffodil like
flowers - accepted method to encourage flowering is to withhold water
for a period.

These are merely examples, not botanical oddities.

It makes sense - quite a heavy investment in flower and seed, so while
the ground is good, concentrate on vegetative growth, but if the ground
isn't good, invest in flower production, and maybe one of your offspring
will find itself in better conditions. And by expressing it this way I'm
not implying any conscious decision making process on the plant's
behalf! ;-)
--
Kay Easton

Edward's earthworm page:
http://www.scarboro.demon.co.uk/edward/index.htm