whats the difference between perennial and hardy?

[l15a27]

whats the difference between perennial and hardy and half hardy?
what are the ones that are green all round but flower in summer?

[Thunderbird+]

Hi, A perenial is a plant which will grow year afer year providing the conditions are favourable. some perenials can be short lived which sounds like a contradiction in terms.
Half hardy, this plant will only grow outdoors as long as the tempreture stays above freezing, it maybe a plant that originates from somewhere warmer, so therefore it's usually treated like an annual.
The last one, I'd say is a perenial but an evergreen one, if it's stmms died down to ground level when the winter came but the roots remained alive it would still be regarded as a perenial but an herbaceous perenial.
Furthe to this an annual completes it's life-cycle in one year and a bienial will comepleting it's life-cycle in two years, ie flowering and setting seed in the second year.
Hope that makes sence. Good Luck Tbird+