"Martin Sykes" wrote in message
...
If a hardy annual or biennial doesn't die off naturally after flowering
then
is there any good reason why I should dig it up instead of leaving it in
place to flower next year?

Martin

'Experiments' have taken place in our garden over many years on this one. I
say experiments cos actually it's because I can't bear to pull up anything
that is still flowering in autumn, and then I leave it there in the winter
to remind me where I can plant next year. In this way many
annuals/biennials have been given the full life that nature intended :-)
And the surprising one for me was antirrhinums - no amount of wind, snow or
permafrost can make these the 'annual' they are supposed to be. I trim them
back medium hard in the spring and off they go again. I've had some on the
go for four years now. Wallflowers are another - as long as they get a trim
to stop them getting leggy, they seem to do well year after year.

Oh and I did notice that my Brompton Stocks have pulled through thus far and
are even budding up! A couple of years ago I saw some in a garden in bloom
in March and thought 'Hah they must have been early plants in the green
house' but now I realise that they *could* just have been left to their own
devices over winter.

Try some and see - if they don't make it you can pull them up in the
spring - or watch as the birds use the strawey remains for nest building :-)

--A