"Inge Jones" wrote in message
. ..
When the books say something will tolerate part-shade, or light shade,
is there any difference between a continual dappled sunlight, or a
corner that only gets sunlight for an hour or two a day, but full sun
when it does get it?

Also, if you have a place that gets no sun at all except for 4 months in
the summer, and for those 4 months it's good sun for up to 8 hours a
day, could you put in a plant that says it needs full sun? We just
happen to have a house at the bottom of our short South facing garden
that stops most of the sun until it gets high enough in the summer to
clear the top of that house. It occurred to me that as many plants are
dormant in the winter they might only care what they get in the summer.

A year or few ago I came across an exhibition on just this at Chelsea FS by
one of the horticultural colleges.

I can't remember all the details, but essentially the thrust was that
dappled shade has parts of the spectrum missing through filtering and
reflections, full sun has the full spectrum. Even N.facing open aspect with
no direct sun is different from Dappled shade.

Hence, woodland plants have evolved to use different regions of the spectrum
to plants liking full sun.

ie there is a differenence - and one that fits with my experience - plants
that like full sun rarley do well in dappled shade but sunlovers can be
quite happy with a few hours of full sun. I once had a lavender hedge in an
E-W side passage that only saw the sun in the very early morning and late
afternoon in summer and none at all in winter. It was vigorous and healthy.


pk