with the
USDA Zone Map
The USDA Zone Map is undoubtedly a great tool
to rate hardiness for landscaping plants.
However this map is ONLY the AVERAGE
coldest temperature, not the coldest temperature
that is possible. In fact, with a very unstable
climate (likely due to climate change) colder
or warmer winters are far more likely. In fact
there have been at least 2 winters in Indiana
in the past 10 years alone that have seen temps
colder than the zone I am in. I am in
Indianapolis, IN. In the Winter of 2014 the temp
dipped down to -15°F in Indianapolis, and
-20°F to -25°F on the north side where I live.
Indianapolis had a zone 5b winter in a zone 6a,
I had a zone 4b/5a winter in a 5b/6a location.
In 2019 I had a zone 5b winter and I am
technically 6a bordering zone 5b. It is ALWAYS
best to go with the colder side rather than
warmer side due to this very reason.
Indianapolis is technically zone 6a, in reality
it is a solid zone 5. Southern Indiana is a solid
zone 6 (which fits the current map).
But Indianapolis area northward is a solid
zone 5, Bloomington area south is a solid
zone 6 (this fits the d 1990 map). The map
really should be updated more than every
20 years especially with a rapidly changing climate.
Virtually the entire country moved up (warmer)
a whole USDA Zone from 1990 to 2012
(most recent). With my own experience
the modern map is not correct in many
locations. Indianapolis should have remained
a zone 5 in the 2012 map. Only minor or
perhaps no changes at all should have been
made with the new map for Indiana. The climate
is changing, but parts of the world are getting
colder as the climate is disrupted from CO2
emissions, as a result we have had colder winters
than the map says we can have. I have had weather
colder than the map says and reached the minimum
temps at least 4 times in 10 years really says something to me.
to rate hardiness for landscaping plants.
However this map is ONLY the AVERAGE
coldest temperature, not the coldest temperature
that is possible. In fact, with a very unstable
climate (likely due to climate change) colder
or warmer winters are far more likely. In fact
there have been at least 2 winters in Indiana
in the past 10 years alone that have seen temps
colder than the zone I am in. I am in
Indianapolis, IN. In the Winter of 2014 the temp
dipped down to -15°F in Indianapolis, and
-20°F to -25°F on the north side where I live.
Indianapolis had a zone 5b winter in a zone 6a,
I had a zone 4b/5a winter in a 5b/6a location.
In 2019 I had a zone 5b winter and I am
technically 6a bordering zone 5b. It is ALWAYS
best to go with the colder side rather than
warmer side due to this very reason.
Indianapolis is technically zone 6a, in reality
it is a solid zone 5. Southern Indiana is a solid
zone 6 (which fits the current map).
But Indianapolis area northward is a solid
zone 5, Bloomington area south is a solid
zone 6 (this fits the d 1990 map). The map
really should be updated more than every
20 years especially with a rapidly changing climate.
Virtually the entire country moved up (warmer)
a whole USDA Zone from 1990 to 2012
(most recent). With my own experience
the modern map is not correct in many
locations. Indianapolis should have remained
a zone 5 in the 2012 map. Only minor or
perhaps no changes at all should have been
made with the new map for Indiana. The climate
is changing, but parts of the world are getting
colder as the climate is disrupted from CO2
emissions, as a result we have had colder winters
than the map says we can have. I have had weather
colder than the map says and reached the minimum
temps at least 4 times in 10 years really says something to me.
•
When landscaping please take this into consideration,
and go a zone or at least a half a zone (5°F) colder.
If you are a zone 6a, Do not use zone 6 and warmer
plants unless it is protected and you or your customer are
aware and are willing to take the risk.
and go a zone or at least a half a zone (5°F) colder.
If you are a zone 6a, Do not use zone 6 and warmer
plants unless it is protected and you or your customer are
aware and are willing to take the risk.
•
Sum up: The 1990 map still is more realistic than the 2012
(current) map which is too warm for lots or perhaps the whole country.
(current) map which is too warm for lots or perhaps the whole country.