Wrapping in burlap is typical. It breathes adequately yet still provides significant cold protection.

Juta?

Wrapping in burlap (juta)+ straw + outside bubble wrap ?three strats of protection?

to save the stem bubble wrap would be best.

Dario what zone are you in?

I think zone 8b brescia italy (i think) - This year has made two months every day below zero with some days also -7

All Last years temperature good below 0 is only this year particulary

the past years did not cold Because in my normal area is maximum one week -2 -3..... instead this year Has Been very cold two months all the days at -4 with some days at -7 (celsius) I would understand then protecting them which variety can be grown outdoor and if there is also possibility of cultivating one variety with fruit edible