Plant Doctor Archive

Green Goddess, not!

WE planted six Cordyline 'Green Goddess' in a retaining wall over a year ago. Since then, one has rotted and three have really skinny, wobbly trunks compared with the remaining two plants which have thick trunks and a lot of healthy leaves. Can we fertilise the skinny ones to make them healthier and thicker? We also planted two others in the front garden at same time and their trunks were also skinny and the leaves started curling, yellowed and browned so we pulled them out.

IT SOUNDS like your 'Green Goddess' have a root problem. While cordylines are generally referred to as ideal plants for poorly drained soil, or soil that gets waterlogged in winter and dry in summer, some of the new hybrid cordylines appear to be fussier in their needs.

I recommend you stake the wobbly ones to prevent any movement and help them establish new roots. Don't fertilise them. Rather, spray the leaves and drench the soil around them with a solution of aliette, sold as No Root Rot in garden centres. At the same time, make sure the soil is as free-draining as possible and, if you have an irrigation system, turn off the sprinklers closest to the cordylines to allow the soil to dry out.

On the other hand, it may be that the plants dried out excessively after planting before they had the chance to grow roots into the surrounding soil. This can also lead to root problems. If this could be the case, stake as above, water in dry periods and mulch to maintain soil moisture.

Reproduced with permission from the former Weekend Gardener magazine. The views expressed here are not necessarily those of the RNZIH.