Is the hemp palm hardy? How to overwinter Trachycarpus correctly

The fan-shaped leaves with long stalks are characteristic of the Trachycarpus palm, which is native to the high mountains of Asia. The trunk is covered with fine or coarse fibers that fall off over the years. Hemp palms can be planted out in the garden but also kept in tubs, although specimens in tubs have different requirements when it comes to overwintering.

Hardiness of the hemp palm Trachycarpus

If you want to keep a palm tree outdoors in Germany, you have to make sure it is winter hardy. Here the hemp palm Trachycarpus particularly stands out. Originally it grows in mountainous regions with a very harsh climate, at altitudes of 2500 m above sea level. Here these plants are subject to strong temperature fluctuations and are otherwise exposed to the most adverse conditions.

The Chinese hemp palm (Trachycarpus Fortunei var Tesan) has the best winter hardiness of up to -17 degrees, which is also the best known and most popular type of hemp palm. Other subspecies still tolerate temperatures between -7 and -13 degrees. How hardy a hemp palm actually is depends on the location, the age of the palm and its size. Even young hemp palms and specimens in tubs are usually only partially hardy.

In addition, the number of winters that they have already spent outdoors also plays a role in the winter hardiness of individual plants, even at higher minus temperatures. The better they are used to the frosty climate or the later you plant them outdoors, the better they will do. In general, it is advisable to overwinter hemp palms that are younger than 4 years and significantly smaller than 100 cm indoors.

Winter protection starts with planting

Winter protection does not start with the first minus degrees, but already with the planting, with the choice of the right location. The condition of the soil is no less important.

• Location should be sheltered from the wind
• Ideally in front of a south-facing house wall
• Climatic conditions are best here
• Pay attention to well-drained soil
• The ground must not become waterlogged, even if it rains continuously
• It is best to put a drainage layer in the planting hole as a preventive measure
• Drainage should be 10-15 cm thick and made of coarse materials such as gravel
• Mix loamy soils with plenty of coarse-grained sand for better permeability

Even if the location and soil conditions outdoors are optimal, winter protection should neither be applied too early nor left on the plant for too long. Only when persistent frost and temperatures below minus 5 degrees are to be expected is it time to provide the hemp palm with appropriate protection. As soon as it gets milder again, around March, this should be removed again.

Overwinter in the garden

When it comes to properly protecting planted hemp palms, the first thing to know is that winter wet conditions are far more threatening to these plants than frost. This is especially true for the root area and the sensitive heart of the plant. Nevertheless, they are quite robust and with a little help they can survive many winters unscathed.

Protect root area and trunk

When temperatures fall below -5 degrees, both air and soil temperature, it is time to take protective measures. First, the root area is provided with a cover. This can be a humus layer consisting of dry leaves and compost or bark mulch. The cover should be about 30 cm thick to prevent the ground from freezing completely. In particularly cold winters and at temperatures below -12 degrees, it is advisable to also protect the trunk. You can do this by wrapping several layers of fleece, jute or burlap around it.

Palm heater against extreme frosts

A palm heater is a special plant overwintering system in the form of a heating cable. This can be used both in the root area and to protect the trunk.

• To protect the root, bury the heating cable around the root area
• Then connect the cable to the power supply
• First wrap the trunk with a reed mat
• Then wrap the heating cable spirally over this mat from below
• Then fix the cable with adhesive tape to avoid slipping
• Wrap jute, fleece or a similar, breathable fabric over it
• Avoid direct contact of the heating cable with the trunk as much as possible

If the temperatures reach extreme minus degrees, the hemp palm can also be wrapped in foil. However, this should be removed as soon as the weather conditions improve and temperatures rise again.

Protect the heart of the hemp palm

The most sensitive part is undoubtedly the heart of the trachycarpus. Here, in the vegetation point, the palm forms new fronds. If too much water penetrates here and freezes, the resulting ice crystals can damage the tissue of the young fronds, especially on the leaf bases. If the temperatures rise, the dead tissue can rot and destroy the entire heart of the palm, and the plant dies.

From a temperature of -12 degrees, the palm fronds are usually deep-frozen. If you then touch the unprotected fronds, for example to shake the snow off the leaves, the fine capillary channels in the leaves can break. As a result, plant sap can no longer be transported through these capillaries in spring and the damaged frond dies.

The best way to protect the heart and leaves is to loosely wind or unwind the fronds with a rope or string. to tie up It is better to avoid using wire for binding, as it could damage the leaves. In the event of prolonged precipitation, whether rain or snow, additional moisture protection in the form of a film cover is a good idea.

Under no circumstances should the foil be closed at the bottom to avoid the formation of condensation. To prevent the cover from being blown away by the wind, you can weigh it down with two smaller stones that you attach to the bottom of the foil. If the weather improves, the foil must be removed.

Hibernation in the house

Hemp palms of the genus Trachycarpus should be planted out in the garden at the earliest when they are 3 - 4 years old. Only then are they robust and big enough to survive a normal winter outdoors, with the appropriate protection of course.

• Specimens that are younger are better off frost-free in the bucket over the winter
• Put plants in as soon as outside temperatures drop to -5 degrees at night
• Winter quarters should be bright and cool
• Temperatures ideally between 5 and 10 degrees
• The cooler the room, the darker the hemp palm can stand
• Avoid temperature fluctuations as much as possible by changing over several times
• Hibernation of older palms in tubs, in mild locations also possible outside
• They tolerate temperatures of -6 degrees
• Good frost and moisture protection is particularly important here
• Plants in tubs are generally more sensitive to frost
• Location in front of a sheltered and shady house wall is recommended

To protect against frost and moisture from below, place the bucket on a styrofoam plate, a wooden pallet or something similar. The bale is covered with a thick layer of leaves and fir twigs and the tub is wrapped several times with fleece or reed mats and also with bubble wrap. If the temperatures continue to fall, it is better to overwinter an older palm tree indoors as well.

care in winter

Planted hemp palms must be watered every now and then in winter, but only sparingly and only on frost-free days. Plants that do not survive the winter are very often dried up and not frozen. However, fertilizer should be avoided completely. If you spend the winter indoors, the dry air can quickly lead to pest infestation. To prevent this, it can be helpful to occasionally spray the plants with lukewarm water. A good time to repot a Trachycarpus, if necessary, is before moving outdoors the following spring.

Learn more about overwintering plants