10 expert tips on growing palm trees in cold climates

Most palm trees are only seen in tropical climates. But fortunately, there are also palms that grow well in subtropical and temperate climates. You may be surprised to learn that there are even palm trees that can survive temperatures below freezing and snowfall.

To successfully grow palm trees in cold climates, you need to choose a palm that is strong enough to withstand the winter in your area. Utilizing the microclimate of your home and garden can make a huge difference in the number of palm species you can grow.

Acclimatization and soil conditions can also play a significant role in how quickly your palm "establishes" in the new location. Growing palms in zone 8 should not be a problem if you follow my tips below.

1. Find your hardiness zone

Europe is divided into different hardiness zones. Check the map for where you live. Click on the map to see the hardiness zone maps and determine from the table which temperature zone you are in.

You can also check past winter records in your area to see if you live in a microclimate. A microclimate is a small area with a slightly different climate than the general climate of a particular region. Knowing your hardiness zone can help you determine your palm tree selection.

2. Select the right palm tree

Not all palm trees can withstand cold temperatures in the same way. Since palms come from different countries, they have varying cold tolerances known as "cold hardiness." The best way to determine the lowest temperatures and humidity levels a palm can tolerate is to look at its natural habitat.

Millions of years in the same environment have allowed palm trees to adapt to recurring weather conditions. As a result, some palms are more cold-hardy than others. That said, palms from the Mediterranean region are more cold-hardy than those from warmer climates like Fiji.

When choosing a palm tree for your climate, pay attention to its cold hardiness. While most can be grown in zone 8, there are some very cold-tolerant palms that can even survive in zone 7.

The difference between cold-hardy palms and warmth-loving palms is quite significant. The coconut palm can tolerate cold down to 4°C. Meanwhile, the Needle Palm, the hardiest palm tree in the world, can withstand cold down to -20°C and is known to survive even -31°C.

3. Use the microclimate of your home and garden to your advantage

Every garden has microclimates where temperatures can be half to a full zone warmer (or cooler) than the rest of the region. In most gardens, drainage, soil conditions, light levels, and other characteristics often vary over just a few meters. To use this to your advantage, you should divide your garden into microclimate areas.

Look for sheltered spots from the wind, the compass orientation of your house, the lowest and highest points, tall evergreen shrubs and trees, full sun and shaded areas, water features (if present), etc. The easiest way to find warm microclimates is by absorbing frost cover.

To get more accurate data, place inexpensive thermometers throughout the garden. They should be about 1 meter above the ground. You will notice temperature fluctuations during a cold winter night. In cold climates, the microclimate can make a huge difference, allowing you to grow 400 types of palms instead of 50 types.

You can protect the palm tree from cold winter winds by planting it behind dense bushes, a windbreak, or a sheltered courtyard. Other warmer spots include near a building, fences, hard surfaces, an overhanging porch, a water feature, under the canopy of a taller tree, or on a hill.

Moreover, palms will stay warmer near a stone or brick wall, or other structures that absorb heat all day and release it at night to keep the palms warm.

4. Acclimate your palm tree.

As palm trees become increasingly popular, many palm nurseries grow thousands of palms to meet the demand. Usually, all types are grown at the same location.

Since most nurseries are located in warm climates, those palm trees will almost never experience temperatures below freezing. If you buy a hardy palm that has never experienced cold weather and plant it in a colder climate, it will likely not survive.

Hardy palms need to be acclimated so that they can better withstand cold weather. Acclimation, also known as acclimatization, must happen slowly to avoid shock.

Some nurseries allow their hardy palms to acclimate before selling them to customers from northern regions. However, others simply do not have the time for it. This is yet another reason to buy palms from well-known and trusted palm nurseries that care about the quality of their trees rather than just making money.

To acclimate the palm tree to the cold, you need to gradually expose it to cold temperatures while still providing frost protection. There are many different wintering techniques. I recommend starting with the basics.

5. Allow sufficient time for root development.

Mature palm trees are more likely to survive cold weather because their trunk is thicker. They have more leaves to protect the main part of the tree, the bud/spear, and finally, their root system is more extensive.

Some hardy palms even develop a sheath, an outer layer of fibers that protects their trunk from the cold. Young palms with thinner bark and a smaller root system are not strong enough to recover from cold weather.

Another thing to keep in mind: if you transplant a mature palm to a new location and do not give it enough time to develop sufficient roots before the cold weather, it may not survive. Therefore, I recommend planting palms in the spring. This way, they have enough time to develop a healthy and strong root system.

6. Ensure good soil

Although many palm trees can adapt to different soil types, most do best in well-draining, organically rich soils. Some palm trees also do well in clay soil, as long as some organic material is added and the drainage is good. An additional benefit of clay soil is that it is similar to paving, retains heat, and moderates temperature.

To determine what type of soil you have, you can send a soil sample for testing to soil research companies. Or you can simply do a "ball test." Dig up some soil and try to make a ball.

The perfect soil will form a crumbly ball because it has particles of different sizes. Some particles are made of sand, some of clay, and others of organic material. If your soil consists mainly of clay, you will get a sticky mass. Sandy soil will not form a ball at all.

Clay soils are good at retaining water, but they have slow drainage and prevent oxygen from penetrating the root zone. Sandy soil is also a problem because it drains too well and washes away nutrients after each rainfall.

To improve sandy or clay soils, add plenty of organic material, such as peat moss and biological humus. Humus is essentially a dark, organic material that can no longer be broken down. You can easily find humus at local garden centers. This should provide the soil with nutrients and promote water retention and drainage.

7. Improve drainage

Check the drainage by digging a 30 cm hole and filling it with water. After it empties, refill it 10 hours later and see how long it takes to drain. In well-draining soil, the water should disappear within about 2 hours. If this is not the case, consider improving the drainage before you plant. Otherwise, standing water will cause root rot and your palm will die.

You can improve drainage by:

• adding builder's sand and organic material to the soil,
• adding stones to the bottom of the hole,
• drilling holes in the ground to loosen the soil.

8. Fertilize your palm tree

Another important factor for successful palm growth is health. The healthier the palm, the greater the chance it will survive the cold winter temperatures. Palm trees go through multiple acclimatization and de-acclimatization phases throughout the year. Therefore, it is crucial to provide them with sufficient nutrients during the warm months.

I always recommend using a high-quality slow-release fertilizer. And not a cheap one that gets washed away after a few rain showers. This gives the palms enough time to absorb all the nutrients during the warm months and prepare for winter.

Research shows that fertilizing in the middle of winter has no effect on the palm's chances of survival. As it gets colder, palms enter a dormancy phase, during which their photosynthesis process slows down and they absorb fewer nutrients.

9. Improve water uptake

One of the biggest problems for palms is drought stress. Drought stress can weaken the palm and affect its resistance to cold. Aside from the deep watering technique that is widely used, there is another small trick you can do.

Install a 10 cm plastic drainage pipe directly next to the root ball when planting a palm. A drainage pipe is usually round and has small holes used for good water drainage in basements.

The pipe should be slightly higher at the top than the mulch and extend all the way to the bottom of the planting hole. This way, you can get water to the roots of the palm!

This is a great solution for watering palms during winter. You can use warm water to provide even more warmth to the roots of the palm. Make sure to use a cap on top so that winter air does not reach the roots. And also to prevent moisture loss during hot summer days.

10. Protecting the palm from cold

Especially for newly planted palms, cold protection can play an important role. The palm needs three full growing seasons to fully develop. In heavy clay soil, it can even take longer. When your palm is adjusting to the new environment, it is extremely sensitive to cold, drought, or other stress.

So I highly recommend using cold protection in the first three years. There are many different techniques you can use to protect your palm, but here are some of the easiest:

• Mulching. The easiest way is to apply 15 to 30 cm of mulch. This protects the roots and the bottom of the trunk from freezing.
• Christmas lights. Another simple thing is to place Christmas lights around the trunk of the tree. This gives a festive look and adds a few degrees of warmth during cold winter nights. Keep in mind that all warmth will disappear if it’s windy. 
• Anti-desiccant spray. Water loss from the foliage is one of the biggest problems during cold winter days, especially when freezing temperatures are accompanied by bright sunshine and cold winds. Anti-desiccant spray can help! This spray creates a waxy layer that prevents water loss from the tree's foliage.
• Watering heavily. Water the soil around the palm heavily before a cold snap. This warms the roots because moist soil loses heat more slowly than dry soil. Using lukewarm water instead of cold water will warm the roots even more.
• Mummifying. This approach requires a bit more effort. Use a synthetic blanket that does not retain moisture. Wrap the trunk and as many leaves as possible. Secure it with duct tape. You can add Christmas lights around it for extra warmth.

Do remember that a bit of cold weather is good for the palms. It makes them more hardy. So don’t wrap them up immediately at the first signs of winter. 

In conclusion

With the above tips, you can easily grow hardy palms in zone 8. By cleverly utilizing the microclimates in your garden along with protection techniques, you can even keep less hardy palms. This means that if you live in zone 7, you can now grow palms that are only hardy to zone 8.