Tulips are cold-hardy plants that can survive winter in zones 3 through 9. However, you might be wondering, ‘will frost kill tulips?’
How low can temperatures go before tulip plants get damaged? Let’s find out below.
Will frost kill tulips?
Tulips are attractive to some gardeners as these plants are among the first to show up in spring. Plus, the dainty, cup-shaped blooms are a time-honored classic and definitely worth the effort in growing them.
Tulips and similar bulbs have a characteristic that allows them to survive frost even when they’re planted outside. Aside from being buried several inches underground (where the soil is warmer), tulip bulbs are adapted to thrive in cold temperatures where other plants fail (or dieback).
You won’t need to do anything except let nature take over and your tulips are likely to come back and greet early spring with cheery new growth.
Cold is a must to bring tulip plants out of dormancy. This is what’s referred to as a ‘chilling period’, or a set number of hours before a tulip could start to grow and flower again.
The hours will depend on the tulip cultivar or species, and in warmer zones, it’s recommended that people dig up their tulip bulbs and put them in the freezer for several months to satisfy the chilling requirement.
What Temperature Can Tulips Survive?
Typically speaking, tulip bulbs can survive frozen ground and temperatures of up to minus 40 degrees F.
Plant damage occurs when temperatures go down to minus 29 degrees F. The tulip’s buds and flowers will start dying first, then the plant will suffer when the frost extends to more than one or two days.
You might need to protect your tulip plants if there’s a hard frost coming in. However, if the forecast is a few nights of light frost then you won’t have to worry about your tulips as they will likely survive.
As a general rule, dormant tulips are unlikely to get damaged during winter and cold spells. However, new spring growth, including tulip flowers are vulnerable to frost and won’t likely make it through.
How to Protect Your Tulips From Frost
There are several ways to protect your tulip bulbs from frost:
Add Mulch
Mulch can help keep things nice and warm so your tulips have a higher chance to survive several days of hard frost. Apply 2 to 4 inches of organic mulch around the plant to insulate it from the cold, then remove the layer once the risk of frost has passed.
Replant
Tulip bulbs that are planted too shallow may not survive the winter. If this is the case, then you can replant your tulips and ensure a depth of 6 to 8 inches, or roughly twice the height of the bulb. At this point, you can add an inch or two of organic mulch to ensure you’ll see your plants bounce back in spring.
Dig Up
You can dig up tulips once it dies back to keep them from coming out of dormancy too soon. You can keep the bulbs inside your house and in a refrigerator so they will experience the chilling hours it needs to flower the next growing season.
Add Shielding
Tulips won’t need too much protection if they’re growing in zones 3 to 9, but you can put up some barriers to keep away hard frost.
You can use frost cloth, blankets, or similar coverings, a milk jug, or even an overturned trash bin to cover your tulips. A makeshift hoop house will work as well. Just remember to remove the barrier when all danger of frost has passed and when the temperatures are climbing up.
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