What's a safe temperature for tender plants? When the nightly temperature falls, frost can form, even above 32°, because the air is colder high above the ground and the frost can form up there and then fall down onto your garden and do some damage, even if it's 36° on the ground. So many factors come into play, including wind, concrete, houses, trees and other structures, etc etc etc. Because of all this, you might want to consider 36° as "the danger zone".
In your average springtime, you have a 90% chance that there will be no 36° nights by May 8. In other words, you can pretty much count on being safe from frost by that day. But we want to get those tomatoes in the ground as soon as possible, right? We see that there's still an 80% chance of 36° on April 11, so we don't dare plant that early. We wait a few days and by April 22 we are at the 50/50 point. At this point, we are close and we can start watching the weather forecast. If the upcoming week's forecast doesn't show below 40°, then it's probably okay to risk planting out your plants. If conditions change and a surprise frost does threaten, there's always things you can do to protect plants from frost.
Temperature | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
---|---|---|---|---|---|---|---|---|---|
Last 16° | Mar 2 | Feb 22 | Feb 16 | Feb 11 | Feb 6 | Feb 1 | Jan 26 | Jan 19 | Jan 5 |
Last 20° | Mar 12 | Mar 4 | Feb 26 | Feb 22 | Feb 17 | Feb 13 | Feb 8 | Feb 2 | Jan 25 |
Last 24° | Apr 1 | Mar 23 | Mar 17 | Mar 11 | Mar 6 | Mar 1 | Feb 24 | Feb 18 | Feb 9 |
Last 28° | Apr 9 | Apr 4 | Mar 31 | Mar 28 | Mar 25 | Mar 22 | Mar 19 | Mar 15 | Mar 10 |
Last 32° | Apr 23 | Apr 19 | Apr 16 | Apr 13 | Apr 10 | Apr 8 | Apr 5 | Apr 2 | Mar 28 |
Last 36° | May 8 | May 2 | Apr 28 | Apr 25 | Apr 22 | Apr 19 | Apr 15 | Apr 11 | Apr 6 |
The charts on this page show the probabilities of receiving a certain temperature on a certain day. Some examples that might help:
Temperature | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
---|---|---|---|---|---|---|---|---|---|
First 16° | Dec 4 | Dec 13 | Dec 20 | Dec 26 | Jan 1 | Jan 7 | Jan 13 | Jan 22 | Feb 6 |
First 20° | Nov 20 | Nov 30 | Dec 6 | Dec 12 | Dec 17 | Dec 23 | Dec 29 | Jan 4 | Jan 14 |
First 24° | Nov 7 | Nov 13 | Nov 17 | Nov 21 | Nov 25 | Nov 28 | Dec 2 | Dec 6 | Dec 12 |
First 28° | Oct 22 | Oct 28 | Oct 31 | Nov 4 | Nov 7 | Nov 10 | Nov 14 | Nov 17 | Nov 23 |
First 32° | Oct 7 | Oct 12 | Oct 16 | Oct 20 | Oct 23 | Oct 26 | Oct 29 | Nov 2 | Nov 7 |
First 36° | Oct 1 | Oct 6 | Oct 10 | Oct 13 | Oct 16 | Oct 19 | Oct 22 | Oct 26 | Oct 31 |
Now that you know your frost dates, use our Garden Planting Calendar for Cartersville, GA to know when to sow and transplant your various vegetable plants!
Data is provided by the NOAA National Centers for Environmental Information. Photography by Garden.org member TBGDN.