If you have? Lunaria annua (Honesty) it is a plant best known for its seed cases and is a biennial (but once established should continue to appear)
It has deep tap roots, and is related to the brassica family. Keeping them in pots for any length of time prevents the tuberous like roots developing properly, therefore unlikely to flourish.
This is a poor soil plant which hates acidic soil and likes to be in company with other plants. Better to plant in the garden in plenty of good home-made compost or leaf-mould but no manure or fertilizer. I have never heard they need shade as they grow out in the open and cope in most areas.
If you do keep it in a pot the deeper the better with plenty of moisture and do not over feed.

Thanks Drc,
it is in a big pot so I recon it will be okay `till autumn then I`ll plant it in a border. That should make him happy!
Regards Pete.

If you have semi-shade Pete, 'he' will be even happier!

Hi Sheila
By pure chance that is a good description of his spot.

:))