| This map follows the
UDSA cold hardiness system, which is based on the average minimum
temperatures in each area and gives a guideline for plant adaptability.
Plant material
on our website is related with a USDA zone number, which is correct to the
best of our knowledge. Zones can be divided further into "a" or "b". When
used, "a" refers to the colder half of the zone and "b" to the warmer
half.
For example,
Zone 4a indicates temperatures of -25° to -30°F. However, we cannot be
responsible for hardiness since growing conditions, site selection and
ununsual winter weather will affect winter survival. |
