The citrumquats have survived winter inground. The lowest temperature was -13/-14 C, or possibly a bit lower. They have been covered with peat, rafia, straw and white cloth. It seems they have inherited the strong dormancy trait from kumquat. They are growing now but with a delay compared to Poncirus.
Amber. New growth is appearing. No bark damage.
Maroon. This is the most vigorous one. New growth is appearing. Also no bark damage.
Carmine. Growing but has some bark damage and significant twig damage.
For comparison citsuma Prague has frozen nearly to the ground level. Only the rootstock and a few centimeters of Prague wood are alive. The rootstock is not pure Poncirus, but a citrange or citrumelo.