The secret to growing hardy palms

If you live in a cold climate and want to grow palm trees in your garden, you are not alone. More and more people want a tropical paradise in their own garden.

Many people do not realize that certain palm trees can be grown in wet and cold European countries. Some hardy palms can tolerate frost down to -18C.

The secrets to growing hardy palm trees in a cold climate are to know:

• what your hardiness zone is. 
• what the lowest temperatures you can expect during the coldest months are,
• which palm species can grow in your area and
• how you can protect them from unexpected cold moments.

Your hardiness zone

First, determine your hardiness zone. Once you know your zone, you can use the list to find out which palm species can grow in your area. There are 11 main zones. Each hardiness zone is a geographically defined area. In each zone, specific plants can grow that can withstand the minimum temperatures of that zone.

The zone map is a good starting point. However, it does not take into account heat, humidity, soil moisture, the number of frost days, and the risk of rare catastrophic cold fluctuations.

Cold tolerances of palm species

The challenge of growing palms in colder climates is that most prefer warm and humid weather. Since all palm trees come from different regions, some palms can tolerate cold temperatures better than others. This is because palms have different cold hardiness ratings. These are measured based on the lowest temperature a palm can withstand.

There is a huge list of hardy palm trees that can grow almost anywhere. Some are very expensive and hard to find. Below is a list of the 10 most popular hardy palms. They have become popular because they are durable, hardy, and inexpensive. Moreover, they are easy to find and require little maintenance.

Here are more details about the most popular hardy palms. 

Coldest temperatures in your area

Another important thing to know is how cold it gets in your area during the coldest nights. Many people incorrectly guess these temperatures.

Tip: check the local weather log for your region. Or use a maximum-minimum thermometer in winter to determine the lowest temperatures. Also, determine if that low value is typical for most winters. Even tropical areas like Spain can occasionally experience unusually cold weather.

People living right on the border of hardiness zones may experience colder/warm temperatures than what the zone map shows. The warmer the temperatures in your area, the more palm trees you can grow.

Palm tree acclimatization

It is not enough to only know the hardiness of a palm species. Before you plant palms in a cold climate, you need to acclimatize them to the cold temperatures. If you buy hardy palm species that were grown in a tropical climate and have never experienced cold weather, they are unlikely to survive in a colder climate.

It is therefore important to buy palms from well-known and trusted nurseries. Find out if they allow their palms to acclimatize before selling them to customers in cold regions.

Another thing to keep in mind is that not every winter weather is the same. Research has shown that sudden cold changes are worse than a gradual temperature drop. If the weather gets colder over a longer period, palm trees have time to slow down their processes. This way, they gradually enter a resting phase. During a sudden cold snap, palms do not have time to prepare. This kind of weather change often leads to frost damage.

Microclimate

A microclimate is a relatively small area of about a few meters or even smaller, that has a slightly different climate than the general climate in an environment. You can create your own microclimate by sheltering palms with trees and shrubs.

Sheltered palms are more likely to survive cold winter weather than unprotected palms. Planting a palm tree near objects that absorb heat during the day and release it at night is another smart way to create a microclimate.

Objects like rocks, buildings, fences, or hard surfaces keep your palm warmer during cold nights. By creating a microclimate in your garden, you can certainly expand the list of possible palms.

Winter protection for palm trees

This brings me to the last important point, frost protection for your palm trees. You can protect your palms from sudden temperature changes and during extremely cold nights by using a warm cover, light bulbs, and heating.

The most important part of the palm tree is the heart/spear. If the spear gets damaged, there is a good chance that the palm tree will not survive. Often, palm trees die then.

If you plan to plant a palm, give it enough time to develop a root system. Therefore, I recommend planting it in the spring, before the cold weather begins. If you fertilize regularly, you will make them stronger and more tolerant of sudden temperature changes.