After the winter, the oleander (Nerium oleander) often shows signs of drought damage. Read here how you can tell if the oleander bush has frozen and how you can save it.

In a nutshell

  • Oleander often dries up after winter
  • Causes: fungal infection, insufficient watering and frost damage
  • Vitality test provides information about the condition of the bush
  • Remove dead plant parts - if necessary, cut back hard
  • if roots are affected, discard oleander

Identify frozen & dried up oleanders

You can tell whether the oleander has frozen or dried up by its appearance: the leaves lose their green, turn yellowish or brownish-grey and are limp. It is also typical that it does not form any new leaves on the affected shoots.

Why does oleander dry up?

Drought damage can usually be traced back to incorrect watering in winter, with very often too little watering. However, oleanders also need regular watering during the winter. How often and how much the shrub needs to be watered depends, among other things, on the temperature in the winter quarters: the warmer the shrub is, the more water it needs. If the oleander appears dried up despite regular watering, it may be suffering from Ascochyta dry rot:

  • typical fungal disease
  • first individual parts of the plant die, later the whole plant
  • usually after hibernation, but also possible during the growing season
  • in case of infestation: cut back vigorously into the healthy wood

Notice: Unfortunately, if the roots are affected by the fungus, the bush cannot be saved. Do not dispose of it in the compost, but in household or organic waste.

Oleander froze

A dried-up appearance can very often be attributed to frost damage. Since the oleander originally comes from the Mediterranean region, it does not tolerate very cold winters in local regions very well. It can cope with temperatures down to -5 degrees Celsius for a short period of time, but minus degrees damage the shrub in the long term.

  • first the leaves freeze, then the tips, branches and trunk
  • affected leaves dry up and turn brown
  • frozen shoots turn grayish-green
  • if roots are frozen, discard oleanders

Save frozen oleander

The oleander usually recovers from slight frost damage. The same applies if only a few leaves or shoots have dried up. Water the shrub carefully and then wait a few days. Ideally, its appearance will improve: the foliage is no longer so limp and may even appear a little greener. It looks bad if there is little or no improvement. In this case, it is best to cut back the shrub vigorously:

  • remove frozen plant parts
  • then root pruning: remove all brown roots
  • Repot oleanders
  • put in a new substrate
  • Add long-term fertilizer (e.g. compost).

Tip: To determine if the oleander is still alive, do a vitality test. Carefully scratch a few shoots and check the colour: if the shoots are green, the bush is still alive. If, on the other hand, they are brown or brown-black, the oleander has died and is irretrievably lost.

Protect oleanders from frost

To prevent the bush from freezing and drying up, adequately protect it from cold and frost. It is best to overwinter potted plants in a frost-free winter quarters, such as in an unheated conservatory or cold greenhouse. It is important that the room is bright and the temperature is between 2 and 10 degrees Celsius. To overwinter the oleander outdoors, take the following frost protection precautions:

  • in the bed: protect the root area with leaves and brushwood
  • protect above-ground plant parts with fleece
  • Place potted plants on styrofoam or wooden board
  • Protect the container with bubble wrap or coconut mat
A frost-free winter quarters, such as the unheated conservatory.

frequently asked Questions

How to prevent Ascochyta blight?

To prevent dry rot, regular spraying with an antifungal agent is recommended. In addition, it is worth coating the base of the shrub with a fungicide and sealing cuts with a fungicide-containing tree wax after cutting.

Are there hardy oleander varieties?

Yes, there are oleander varieties that have good frost tolerance and do not freeze to death so quickly. These include, for example, the varieties Nerium oleander 'Atlas', 'Hardy Red' and 'Villa Romaine'.

How often should you water oleanders in winter?

Basically, the shrub is watered less in winter, but it still needs enough water in the cold season. It is best to water it as soon as the top layer of soil has dried.

Category:

Garden plants