Originally Posted by YAKUZA
lowest -19 but its coldest sinds 10 years
normaly max -10
summer i think 34
best 2 put not hardy in container? end dig it in for summer.
or alsow free soil en dig it up fot winter
If you dig it in for summer, it might not be possible to give them back to the container, because they will make strong roots. Just give them large pot (75 litres and more) and they will grow nicely. In summer, you can keep them outside.