The "robusta" in the name gives hope that the Washington palm will somehow survive all the adversities of winter. But hope is a bad advisor here. Since the plant comes from warm Mexico and the south of the USA, we should rather rely on knowledge.

Washingtonia robusta tolerates light frosts and can be planted out in very mild areas

The palm tolerates some cold

Anyone who observes the growth of this palm tree can see that it continues to sprout its palm fronds even at temperatures between 5 and 10 °C. That is why she is not only allowed to stay outside in summer, but also for a large part of spring and autumn. But what about winter?

When it's freezing it's almost over!

If the thermometer drops to -3 °C, everything is still in the green because the palm tree can still withstand this light frost. However, the temperature must not drop further, otherwise the following scenario threatens:

  • down to -8 °C, frost damage to leaves is unavoidable
  • if it gets frostier than -8 °C, the palm tree dies

Since this palm is not completely hardy, it should be grown in this country as a mobile container plant that only spends the frost-free season outdoors.

Hibernation in winter quarters

A plant that shows so little winter hardiness is only in good hands from the first frost night in a suitable winter quarters. You should overwinter Washingtonia robusta with reduced care as follows:

  • frost-free and as cool as possible
  • with incidence of light
  • e.g. B. in the conservatory or greenhouse
  • with water as needed
  • but without fertilizer, otherwise she gets yellow leaves

Even a warm hibernation is not excluded. However, warm heating air combined with low humidity and a lack of winter light weakens the palm tree. As a result, diseases and pests have an easier time spreading.

tips

Water the palm more often in warm, heated rooms. In addition, you should increase the humidity by regularly spraying the plant with water.

outdoor survival

In the case of a bucket palm and very young specimens, the lack of winter hardiness regularly means that they freeze to death outside in winter. However, in mild regions of the country, an older Washingtonia can be planted out in a sheltered spot. Then she needs further winter protection, so that she survives:

  • The palm and the top layer of substrate must be heated
  • e.g. B. with a transportable, heated greenhouse
  • or a heating coil around the trunk
  • additionally wrap palm fronds with fleece

Category:

Trees