Gardening Zone Map
When it comes to a gardening zone map and using
it, there are a lot of myths out there. Here’s the
practical deal on them.
They’re guidelines not rules
A garden zone is a rough guideline (and I do mean rough) for what will
or won’t grow in your general area. (Get the picture - lots
of qualifications here)
Things to Consider
There’s no single source for which plants grow in which zones. So
you’re going to find different nurseries rank plants differently.
The growing conditions dramatically influence the growing zone in your
garden. Some parts of my garden are an entire zone warmer than
other parts.,/
Nobody wants to talk about it but there was a fair amount of
controversy about the USDA gardening zone map setting zones and
then changing the timeline they’re calculated on to reflect a different
set of data. Some folks say this was politically motivated to
“prove” global warming doesn’t exist. Me? I’m Canadian and don’t
really care what the politicians do - I think the folks on the
committee do their best and because I use the maps as rough guidelines
and not hard and fast rules, it’s “all good” for me.
How to Grow Plants Out of Your Gardening Zone
The trick here is to give plants exactly the conditions they
want. You see, if you stress a plant, it might live within a area
that’s right for it but because it’s stressed a bit, it won’t survive
in colder areas.
Make sure the drainage is right. This is the number one problem
with overwintering plants out of their gardening zone. Most
of the time, the soil is too wet for the plant when you’re trying to
push a plant to survive in a colder area.
Make sure the sunlight requirements are met for broadleaf plants.
As a simple example, broadleaf plants (shrubby plants that hold their
leaves all winter) do not want to be in the bright winter noon
sun. The heat from the sun on the leaf warms up the leaf - the
sweat cells on the underside of the leaf (stomata) open up and the leaf
loses water. It can’t replace it because the ground is frozen so
the leaf “burns” or browns. This happens quite frequently in
early spring. So siting is critical for plants to grow slightly
out of their zone.
Micro-climates.
Plants that are in the direct wind are going to have more stress on
them than plants out of the wind.
Plants that are tucked up against a large thermal mass such as a rock
wall will receive a degree or two of frost protection.
Plants that are planted next to heated basements will get several
degrees of frost protection from heat leaking from the basement
Plants on south facing slopes will start growing faster in the spring
than those on north-facing slopes. This can be an advantage with
hardy plants but a disadvantage if you have a plant that is frost
tender and can be wrecked by a late frost.
Bottom Line
Take nursery tags and advice on the gardening zone map with a
grain of salt and consider them broad guidelines for gardening success.
Click on the map to find your garden zone
Click
here if you have a question about the gardening zone map
