Find out how to protect plants from frost damage so a cold snap won’t ruin your garden.
Temperatures in the low 30F range can kill vegetable crops and tender summer annuals likepetuniasandbegonias.
Plus, find out which plants need frost protection and when you should take action.
Credit:BHG/Kelli Jo Emanuel
BHG/Kelli Jo Emanuel
What Is a Frost?
A hard frost happens when temperatures hover around 32F for a few hours, which kills all above-ground parts.
Frost vs.
Credit:BHG/Kelli Jo Emanuel
Freeze
Below 32F is considered a freeze, which is more destructive than a frost.
Freeze warnings in spring signal the need to bring tender plants inside until temperatures warm up.
If possible, cover your your plants during the afternoon before temperatures start dropping as the sun goes down.
Credit:BHG/Kelli Jo Emanuel
Which Plants Need Frost Protection?
Generally, annual plants that fruit and flower in warm temperatures are most sensitive to cold weather.
Think about which veggies and herbs you harvest in midsummer and whichannual flowers are most colorfulduring the hotter temperatures.
A spring freeze might damage developing fruit and destroy flowers, but these plants will survive.
Thesecool-season vegetablesgenerally can withstand temperatures as low as 26F.
A few cold-tolerant flowers likepansiesandsweet alyssumdon’t mind frosty weather either.
Move Containers Indoors
When possible, bring tender plants indoors.
Smallcontainer gardensand plants still in their nursery pots are generally easy to move indoors temporarily.
A heated location isn’t always necessary.
Moving plants to a space like agarden shedor a garage will provide enough protection during a frost.
However, when low temperatures are near freezing, move your plants to an insulated indoor location.
Be sure the plant cover extends to the ground in all places to create a small dome of insulation.
Woven fabric provides better protection than plastic or paper.
Tie the jug’s handle to a nearby stake to prevent it from blowing away.
Water Well
Did you know moist soil can hold four times more heat than dry soil?
When cold weather is forecast,water your plantswell.
In addition to watering, add a cloche or blanket for another layer of protection.
Add Mulch
Athick layer of mulch, such as shredded bark or compost, can help insulate tender plants.
Cover the entire plant with mulch the night before low temperatures are forecast.
Remove it when the weather warms up again.
Messy and labor-intensive, mulch may not be the best option for large planting areas.
And definitely don’t try this method with fragile seedlings.
Cover them before nightfall to trap warmer air around the plants.
Plastic isn’t breathable, so moisture is easily trapped beneath it.
This can lead to even bigger problems for plants beyond frost.
