Grevillea are mostly Australians and therefore many aren't hardy, but a few will take a minus value in temperature. The flowers on mine at the garden centre are just starting to open, and that's had only the clear roof as protection, seemingly resistant to those northerly winds and minus 3s and 4s. Pick your species carefully, and be prepared to offer them the shelter of a greenhouse, but good ventilation, on the colder days. Gritty compost, on the acid side, and in full sun. Pretty much pest and disease free, so it seems.

Thank you for your reply,will deff look up a good hardy species, do you recomend any?

I'm afraid there isn't a hardy Grevillea - the most hardy is G. juniperina and any cultivars created from that, and even this is not reliably hardy, and needs to be planted in a very sheltered spot, preferably with a wall or fence behind.
Cultivars of G. rosmarinifolia are usually the most popular, but they are half hardy and will need shelter over winter, although, in warm parts of the country (like the West) in a sheltered spot and in a mild winter, they can survive.