Plant Doctor: Parched Pongas

Q: Quite suddenly, over the past two days, two of our pongas look like they are going to die. We need to know why and what to do about it.

A: It sounds as if your pongas have suffered from this summer’s exceptionally dry weather. Tree ferns can tolerate relatively long dry periods without showing any symptoms but when the damage to their roots and dehydration of the trunks gets bad enough they can quite quickly look very sick. This can happen even after the rains have returned as it takes a long time for symptoms to show.

The good news is that they will probably recover, especially if they are quite old established plants. Now the autumn rains are here you don’t need to do anything, just leave them to their own devices. You may not get any new growth for quite a few weeks but I’d be surprised if they don’t put out new fronds by spring.

To avoid this in future apply lots of mulch over the root system to conserve soil moisture in summer. The idea is to try to simulate the bush conditions in which tree ferns grow best, giving them moist soil and high humidity.