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?


Dave R

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

Helmuth von Moltke the Elder