While cold hardy palms can tolerate freezing temperatures, tropical palms may suffer from the cold damage. Usually, palm tree owners, that live in the warm climates, don’t need to worry about cold weather. But, with unpredictable winters in the last couple of years, freezing temperatures don’t come as a surprise.
Can Palm Tree Survive Cold Weather
While cold tolerant palms can survive cold temperatures around 10°-15°F, tropical palms get damaged if the temperatures drop below 45°F. The most important factor is how quickly the temperature drops. If it’s around 60-70F during the day, and all of a sudden 45F at night, even hardy palms can get damaged.
On the other hand, a gradual temperature drop day after day, provides palms with more time to get acclimatized to the cold conditions and enter dormancy stage, thus being able to tolerate lower temperatures without significant damage.
The damages also highly depend on multiple factors like the cold tolerance (cold hardiness) of the palm, establishment time, plant age, health, nutrient levels and palm location in the yard. In addition, the conditions can be intensified by chilly dry winds, dehydrating afternoon sun and duration of the cold.
If you are trying to grow a palm in a temperate climate, it takes three full growing season for the tree to get fully established. If you have a heavy clay soil, it might take even longer.
3 Types of Palm Tree Winter Damage
There are three types of winter damage your palm can get: cold, frost and freeze. The most important and the most vulnerable part of the palm tree is the bud. Bud is where new leaves emerge. If the bud tissue of the palm has NOT been severely damaged, the palm should recover and start producing new leaves during the following summer.
New emerging leaves might be deformed, partially brown or have other abnormalities. It might take from 6 months to one year from the freeze for the palm tree to recover. If the bud tissue has been severely damaged, the palm might not survive.
1. Palm Cold Damage
If the palm has been damaged by cold, you might notice the curling and yellowish-brown discoloration on the older fronds. New growth produced in a few months might be coming out at a slower growth rate than normal.
Some of the new spears might not open. All of these are signs of a prolonged cold weather that will clear on their own after a few months when the temperatures go back to normal.
2. Palm Frost Damage
Frost can be much more devastating to the palms especially those with low cold tolerance. It usually covers the whole foliage causing damage to the leaves and sometimes the bud.
In a few days or even weeks after the frost, you might notice sever discoloration on the fronds of a dark chocolate-brown or even black color. That is a sign of a serious damage.
3. Palm Freeze Damage
Freezing temperatures around 32F or below can be deadly for most of the tropical palms if faced without any winter protection. After experiencing the freeze for any substantial period of time, most or all of the foliage of the palm will be lost.
Several month or even a year after the freeze, there might be vertical cracks visible on the trunk and the crownshaft. Bending trunk, bad odor, and mushy soft crown below the spear are all indication of sever damage.
Freeze damage to the tissue of the trunk will limit the ability of the tree to provide water to the foliage. Unlike regular trees, palms can not regenerate the trunk tissue. Collapsing crown may be a sign that this type of damage has occurred.
Signs and Severity Of Palm Tree Cold Damage
I thought I create a chart for you to show different signs of winter damage. Low severity means the palm will probably grow out of it later in the season. Medium severity means that there is a chance of serious injury that can go either way. High severity means that your palm will probably die.
|Signs of Damage||Severity|
|New growth is green and brown||Low|
|New growth is growing at a slow rate||Low|
|Old leaves are yellowish-brown||Low|
|Old leaves are curling||Low|
|Old leaves are brown or black||Medium|
|New growth is deformed||Medium|
|New growth pulls out easily||Medium|
|New growth is brown or black||High|
|Crown is soft and mushy||High|
|Vertical cracks in the trunk||High|
|Strong odor coming from the bud or trunk||High|
|Collapsing or bending trunk||High|
5 Steps To Saving A Freeze Damaged Palm Tree
It might take a few weeks or even months to see the signs of winter damage. At first, the palm might look completely normal, but then the new leaves emerge deformed and partially browned.
By the end of spring, you will have an idea weather you need to replace your palm. Now, let’s talk about things that you can do.
First, you need to determine the level of injury. To see how extensive the damage is, gently pull newly emerging spear. Sometimes, new spear is very loose and pulls out easily. If that happens, clean out the hollow spot with water.
Make a small hole in area right below the leaf bases to avoid collection of the water that can lead to new growth rot. Check to see if the bud is still alive. If it is green, the palm tree can be saved. If it’s mush, get the shovel out.
2. Spray Liquid Copper Fungicide
Next, we need to protect the palm from bacterial and fungi attack. Spray the palm with liquid Copper Fungicide. After the stress from the freeze, palm trees become more vulnerable to bacterial and fungal infections.
Copper Fungicide has a unique formula that helps fight both. It should be applied no more than twice, 10 days between each application. Drench the bud of the palm with liquid copper using the force of the spray to clean it. This should reduce the chances of bud rot due to microorganisms.
Applying Copper Fungicide around the base of the palm will suppress development of the root diseases. One of the products I found to be very effective is Liquid Copper Fungicide by Southern Ag. It works very well against fungi and bacterial.
Wait for a month or two before pruning any fronds. Prune only dead branches and remove all the died leaves around the bud, so it can dry out. Don’t cut back leaves with brown tips, since palms still extracts nutrients for new leaves from dying fronds.
Be careful not to over-prune. The more green leaves you remove, the less food the palm can produce. Pruning too many leaves will only add to the stress.
4. Antitranspirant Spray
As I’ve mentioned above, cold damage to the trunk tissue or roots may limit the ability of the palm to supply water to the leaves. Spraying your palm with antitranspirant spray is a way to reduce water loss from the foliage during cold weather.
Antitranspirant spray forms a clear film on the plant’s foliage which holds moisture reducing water loss during plant stress. I like spray called ‘Wilt Stop’ by Bonide that I recommend using in the beginning of the cold season as one of the ways to protect palm tree from cold.
Do NOT fertilize your palm trees right away, wait until late summer or fall. Most people start fertilizing as soon as they see brown leaves. Fertilizer is NOT plant food.
Despite it saying “Palm Food” or “Plant Food” on the labels, fertilizer is a mixture of nutrients used to make soil more fertile and promote plant growth. Plants produce their own food, using water, carbon dioxide and solar energy.
Think of the fertilizers as vitamin supplements. You can’t make a sick, diseased, malnourished person healthy with vitamins. When you start fertilizing your sick palm tree, you are asking it to start growing, which creates even more stress on the poor tree. Wait till late summer or spring and apply slow release fertilizer. For more fertilizing tips read my Fertilizing Palm Trees article.
How To Protect Palm Tree From Freeze In The Future
If you know that more cold weather is coming, it’s best to protect your palm from further damage. I have a very detailed article called ‘10 Ways To Protect Palm Trees From Winter Freeze‘ where I go over each way you can protect your palms from cold. There are many easy techniques you can use like:
- Fertilization. Providing the right level of nutrients in the months leading up to the winter season is one of the best way to get palm ready for cold.
- Heavy Mulching. Adding 4-6 inches of mulch will help to protect the roots of the tree from freezing.
- Heavy Watering. Extra watering before the cold snap, helps with water supply and helps with keeping the roots from freezing.
- Antitranspirant spray. It forms a clear film around the leaves and reduces water loss from the foliage.
- Copper Fungicide. It fights bacterial and fungal infections.
- Warm Cover. Use blanket, burlap or other warm material to drape over the palm.
- Palm Trunk and Foliage Wrapping. Wrap warm material around the trunk and the canopy of the palm securing it with a duck tape.
- Heater and Light Bulbs. You can use a propane heater or Christmas lights for additional heat source.
- Heat Cables. They come with a built-in thermostat and can be used around the trunk or around the roots.
- Temporary Greenhouse. You can build a wooden frame above the tree and cover it with double plastic sheet nailing it to the frame.
As you can see, it’s much easier to protect your palm from winter weather than saving it once it got injured. To save a cold damaged palm, you’ll need to have a lot of patience. Don’t give up and remember that sometimes the damage is so severe, there is nothing you can do.
- 10 Ways to Protect Palm Tree From Winter Freeze
- Top 10 Cold Hardy Palms
- How to Save a Dying Palm Tree
- Importance of Microclimate When Choosing Cold Hardy Palms
- Top 10 Palm Tree Care Mistakes
- Top 5 Factors Affecting Cold Hardy Palm Tree Growth