The light freeze occurs at 32°F to 29°F and doesn’t cause significant harm to your garden. Delicate vegetation like crops might suffer some damage. Of course, you need to protect your plants; bring the potted ones indoors, but the hardy plants will manage outside just as well.
We can’t predict hard freeze. It’s evident that it happens as soon as temperatures drop below 30°F but following the weather forecast is your best bet.
When Can You Expect Hard Freeze
USDA Hardiness zones 2 to 7 have a history of low winter temperatures, so they’re most likely to experience a hard freeze.
Freeze damage is characterized differently in each plant. Even if they’re perennials, tender crops won’t survive a hard freeze. Hardy crops, as well as roots, can suffer root damage.
The hard freeze happens when temperatures fall below 28 and stay in the low twenties for over 2 or 4 hours. The hard freeze, unlike the frost, it’s extremely damaging and can kill off a significant part of the vegetation in your garden.