How to Protect Early Fruit Tree Blossoms From Frost

The end of winter can bring some stress when it comes to caring for fruit trees. Fluctuations in temperature can cause early blooming, and then a late cold snap can knock them out. Join North Florida gardener Melissa Strauss to talk about protecting those blossoms from unexpectedly cold weather.

Written by Melissa Strauss Horticulture review by Sarah Jay Last updated: February 20, 2025 | 5 min read

A Malus domestica branch with small red fruit covered in ice, with thin frozen twigs.

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It’s a common issue in places with mild to moderate winters to have your fruit trees begin to flower early. This wouldn’t be a bad thing, except that the weather doesn’t always cooperate. You might get a few weeks of balmy, mild weather, and then, seemingly from out of nowhere, a cold front can rush through and make things complicated.

Your spring-blooming fruit trees, as well as other ornamental spring-blooming trees, bloom in response to the weather. While it’s cold, they remain in dormancy, keeping their buds tightly shut against the winter chill. A period of warming, even one that only lasts a week, can make them think it’s time for spring. Those buds begin to swell and before you know it, they are popping open in the middle of February.

Here in Zone 9a, our last expected frost date is March 1st. But here I am in the first week of February, and the high is 80°F (27°C) today! Needless to say, I’ve got a peach tree that thinks this weather means it’s showtime, and several others aren’t far behind.

Considering it’s a La Nina year, we could end up having a mild transition into spring. But, as we had six inches of snow on the ground two weeks ago, all bets are off in my mind. I’ve learned that some years you just have to take the good with the bad and do your best to preserve your plants and your peace.

From planting to maturity, there are ways to prevent and protect your fruit trees from the dreaded late frost. If you get off on the right foot, certain factors will save you some work in the long run. If your trees are already in their final location, there are still ways to keep those blossoms alive through unpredictable late winter weather.

Choose Frost Resistant Trees

A Prunus persica branch with yellow-orange and red fruit hanging among curled green leaves. — Cold-tolerant trees bloom later, but unexpected warmth or insufficient chill hours can disrupt dormancy.

Sometimes, the best solution to this issue is to make an informed decision when you first purchase your trees. This will look different according to your specific climate, but it’s important to take that climate into consideration when making your selections.

Typically, the more cold-tolerant a tree is, the later it will bloom. Sadly, an extended period of unexpectedly warm weather can make even the latest bloomers think it’s time to get started.

Then there is the issue of chill hours. Each tree, except for citrus, needs a certain number of chill hours. These are hours spent at temperatures between 32-45°F (0-7°C), and they are in important factor in which cultivars will thrive in your climate. Each cultivar needs a certain number of chill hours to properly break dormancy and produce flowers and, thus, fruit.

The tricky part is finding the perfect variety for your climate. To give you an example, the peach I have blooming right now is a ‘Tropic Snow.’ It requires only 150-200 chill hours. My ‘Florida Glo’ peach, on the other hand, needs 250-350 chill hours, so those buds are still sealed up tight.

To find the most frost-resistant variety for your Zone, look for those with your Zone at the top of their range. For instance, if you live in Zone 7, don’t choose a cultivar indicated for Zones 7-9. Instead, Choose one indicated for Zones 5-7. This will be a later bloomer and, therefore, more protected against a late freeze.

Plant Near a South-Facing Wall

A Prunus persica tree with flat-trained branches, green leaves, and ripening yellow-orange fruit. — Plant trees near a south-facing wall to retain heat and provide warmth during cold nights.

Once you have your tree, there are specific places you can plant it where it will be less affected by sudden drops in temperature. One of those places is near a southern-facing wall. This is the wall that will receive the greatest amount of sunlight throughout the day. It will absorb that heat, and at night, the surrounding area will remain slightly warmer than other areas.

While this won’t make as great a difference as some other methods, it can be helpful in those in-between climates. Sometimes, all you need is a few degrees to keep those flowers from freezing.

Plant Near Water

Several potted citrus trees with dark green foliage and bright orange fruit line a courtyard path. — Bodies of water like ponds or pools help regulate air temperature and protect trees from cold.

Planting your tree near a body of water, if it’s possible, may offer a degree of protection from cold weather. If you have a pond or lake on your property or even a pool, this is a good place to plant your tree. The water will stay warmer than the air, assuming it doesn’t get cold enough to freeze.

During the day, the water absorbs and holds onto some heat. At night, the water that evaporates will be warmer than the air and will raise the temperature slightly in its vicinity. This is less effective than the other methods, but can prove helpful a small amount.

Fight Fire With Fire (and Frost with Frost)

Rows of Malus domestica trees are covered in ice, with sprinklers in the background. — Sprinklers form protective ice layers by maintaining a 32° temperature.

This next thing I’m going to tell you may sound unlikely, but there is a science to it, and it can be quite effective. It involves covering your tree with a thin layer of ice and continuing to wet that ice throughout the duration of below-freezing temperatures.

Most fruit blossoms are able to survive freezing, so 32°F (0°C). When the air drops to 28°F (-2°C), even for a brief time, it will kill most of them. The idea behind this method is that it keeps them right at that freezing mark, protecting them from any temperatures that fall below.

The way to do this is to run a sprinkler, starting before the air drops to 32°F and allowing it to run throughout the night. I won’t get too detailed on the exact science, but I’ll sum up, the best I can, why this works.

By starting the sprinkler before it’s freezing outside, you cover the entire tree with water. As soon as the air temperature drops to freezing, the water will freeze. By allowing the sprinkler to continue running, new water will constantly fall on the ice and initiate the melting process. But it will never actually melt because the air is below freezing.

Because of endo- and exothermic reactions, you can maintain a temperature of 32°F inside that thin ice glaze over the flowers. Essentially, the energy produced by the simultaneous processes of freezing and thawing will hold the temperature inside the thin layer of ice at or very close to 32°F. Pretty cool, right?

Cover Them

Multiple fruit trees in a field are wrapped in translucent frost cloth secured around their trunks. — Covering plants with frost fabric, blankets, or sheets insulates them from sudden temperature drops.

Covering your plants is a highly effective way to protect them from an unexpected freeze. Frostproof fabric is available for this purpose, but other covers will work, too. A sheet or blanket can also act as an insulator.

This method works by trapping the warmer air inside the covering, and keeping it just slightly warmer than the air outside. It’s a good idea to use some sort of frame to hold the covering away from the blossoms, as they can be rather delicate.

Cover up during the day, preferably the warmest time of day. The warmer the air is when you cover it, the warmer it will stay. This concept is the same when we talk about mulching the ground. The heat gets trapped inside, and the covering retains some of it. Ensure that your covering goes all the way to the ground so that the warmer air doesn’t escape from below.

Remove the covering as soon as you can, as soon as the air temperature rises back above freezing. The longer it stays on the more chance of crushing the flowers and foliage.

Christmas in February (and March)

A fruit tree with dense green leaves is wrapped in glowing Christmas lights at night. — Incandescent Christmas lights wrapped around trees generate warmth and protect blossoms from freezing temperatures.

Finally, another effective strategy for protecting your blossoms from a late frost is to use light. Christmas lights, to be exact. Wrapping the tree with a string of lights can heat the air just enough to keep those flowers from freezing.

Here’s the catch, you can’t use the newer LED lights, as these do not generate enough heat. The older incandescent lights are the way to go. If you’ve replaced all of yours with LED, don’t worry. Most big box retailers still carry the old-fashioned kind.

This one might just be my favorite, and it’s extra special if a few late snowflakes fall. A little mood lighting in the garden on a frosty night is a great way to finish out the cozy season.