Biennial help please

Can any kind person tell me about biennials. I have grown things like Lupins and Lychnis Coronaria as perennial, but although they will flower again the next year (hopefully) they do look bad after flowering. Many people, such as Christopher Lloyd, suggest growing these as biennial instead, throwing them out after flowering. CL, in one of his books, said that he grew Lupins and others as biennials, originally sowing them in spring for the next year, but in later years sowing them in late summer.

I presume now is the time to sow these - do they germinate as easily now as in the spring? If you sow them just after they have flowered they have less than a year to grow and flower. Many perennials take 2 or 3 years to mature. Can you get a full sized plant after less than a year, and do you have to give them any special treatment. And what plants do people grow as biennials.

 

I bought some lupins, sown this year, and they have flowered; when the flowers have gone over I'll just cut the spike out and leave them for next year. I've done this before and they have flowered again the following year. Though I have found that they will eventually give up the ghost after about 4 - 5 years anyway.

 

I grow the seeds in spring as usual and plant them out in their final flowering positions.

I like single variety beds, so a bed of campanulas will be simply green in it's first year, but get a good start for the following flowering year after which I rip them up.

I don't need to do anything with lupins, the aphids, particularly blackfly kill them off during and after flowering.

 

Thanks for your comments Celia and Rich. I am planning (experimenting) on growing some biennials in pots then moving them into the appropriate place in their flowering year. Then replacing them later in the season by late developers such as Dahlias or Cosmos. The idea is to keep the garden stocked as much as possible with flowering plants - using a sort of shift system. Any further ideas on this would be very welcome.

 

Alan Titchmarsh seems to do that quite a bit. He keeps a few pots of flowering plants to one side to fill in any gaps in the borders. It's a good idea and gives an instant effect. You should have a stunning garden.

 

I like to follow this sort of approach, theproblem being size of plants to replace in the borders - also the 'second flowering' of e.g. delphiniums and Anthemis, etc.Have just dug out and set aide a couple of Knautias which get very straggly and replaced them with Agastache in full flower and upright.
As for Lupis am trying seed for the fist time and after planting in spring I have some good strong plants ready for going out.
By the way I think that a lot of plants classified as perennials are really 'biennials' in disguise.

 

I agree Chobart - I think the distinction between Biennial and perennial is very grey. Some perennials are better grown as biennials according to Christopher Lloyd - such as Lupin. And again according to CL, some biennials are much more perennial if you cut the spent flower off quickly. Th act of producing seed can kill them. CL said it was several years before he realised that some biennial Stocks would last several years, if you deadheaded.