I have had some Delphs for at least 5 years. You can take cuttings in early spring for growing on for the following year. I don't seem to have many problems with slugs on them, though if it is a new plant I put pellets down for the first few weeks.
Hi Chrissieb , delphinimum's will on average last about 4/5 years i have known some to last 7 years.
Lupins can last many many years depending on location
mine up here in Scotland are 8 years old stand in the region of 6 foot hire
although they are loved by slugs ,snails if you put a layer of washed gravel around the base they are free from the evil munchers, don't forget collect the seed, after the flowering season and start fresh plants in pots and grow them on for new plants for yourself or friends and family
Lupins I replace one or two every year so you always have some established mixed with the new.. I think at a guess this makes them have a life of around 4 years to 5 max in my garden.. I find after that they get too big with a lack of flowers compared to the size of the plant...
These are nine years old this year. I didn't really get round to feeding them, but they are still good despite the neglect.
BusyB, those are lovely