Corona's Principles of Planting How to Guide

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Know Your Zone
What does that mean? Zones are climate regions
established by the United States Department of
Agriculture to give an indication of plant hardiness, or
how resilient it is to degrees of cold within a given range
based on average minimum temperatures. There are
19 zones divided by ten degrees into a and b.
The American Horticultural Society also provides
gardeners with a Heat Zone map based on average
regional high temperatures. Check your zone by visiting
their website, where you will also fi nd a link to the
Hardiness Zone map and other valuable resources.
www.ahsgardening.org under Gardening Resources.
Local independent nurseries generally focus on
stocking plants that are suitable for your zone.
HOW AND WHEN TO PLANT
-10 to -5
-5 to 0
0 to 5
-23.3 to -20.6
-20.6 to -17.8
-17.8 to -15
-60 to -55
-55 to -50
-50 to -45
-45 to -40
-20 to -15
-15 to -10
-51.1 to -48.3
-48.3 to -45.6
-45.6 to -42.8
-42.8 to -40
-28.9 to -26.1
-26.1 to -23.3
5a
5b
6b
6a
7a
-40 to -35
-35 to -30
-30 to -25
-25 to -20
-40 to -37.2
-37.2 to -34.4
-34.4 to -31.7
-31.7 to -28.9
3b
4a
4b
3a
1a
1b
2a
2b
Temp (F)
Temp (C)
Zone Temp (F)
Temp (C)
Zone
20 to 25
5 to 10
10 to 15
15 to 20
-15 to -12.2
-12.2 to -9.4
-9.4 to -6.7
-6.7 to -3.9
25 to 30
30 to 35
35 to 40
40 to 45
-3.9 to -1.1
-1.1 to 1.7
1.7 to 4.4
4.4 to 7.2
9b
10a
10b
11a
7b
8a
8b
9a
45 to 50
7.2 to 10
50 to 55 10 to 12.8
55 to 60 12.8 to 15.6
60 to 65 15.6 to 18.3
65 to 70 18.3 to 21.1
11b
12b
12a
13a
13b