AFAIK the accepted thing with wallflowers is to grow them from seed/small
plants one year, have them flower the next year, then take them out
(possibly after letting the seed set and fall if you are trying to maintain
a bed by self seeding).
Effectively treating a perennial as a biennial to maximise the flowering
potential.

Well, had a self seeded wallflower this year come into flower around
May/June, set a load of seed.
I tied up the seed pods (still on the plant) to a cane to mature and meant
to come back later and remove the plant.

However it got left, and has now grown to about 5 times the original size
and has flowered several times (although not as much as the first time). It
is still flowering now.

I am tempted to leave it to see what it will do next year.
If it survives the winter, the options are to just let it get on, and
hopefully seed the bed for future years, or prune it back medium to hard in
the spring to see if it will produce a reasonable amount of flower on new
growth.

Anyone tried this?

Cheers

Dave R

--
No plan survives contact with the enemy.
[Not even bunny]

Helmuth von Moltke the Elder

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