Plant Doctor Archive

Poorly puka and golden ake ake

Last May we planted about three dozen native trees around the back boundary. Out of the three dozen we lost a couple within a short time frame, which we feel is to be expected. But recently (10 months after planting) a golden aka aka just curled up its leaves and died. Plants (pittos) either side of it are fine. We also have a small puka with leaves that are turning yellow and then dropping off. How can we save the puka? What do you think happened to the aka aka?

These trees require a moist, free-draining soil. Were the trees irrigated over the summer months? Did the area where you live experience drought over the summer months (and maybe still experiencing drought)? With irregular watering, or prolonged periods of dry weather followed by wet weather, or in heavy clay soils that are not free-draining, plants can collapse due to root disorders caused by soil fungi — most likely to be phytopthora (root rot). Some plants are more susceptible than others.

The Golden Ake Ake is very tolerant of drought conditions as it has a tough leathery leaf and is indifferent to soil conditions as long as it is well drained. If the soil is not well drained, root rot sets in and causes the plant to collapse. Remove the tree and destroy it to stop the disease spreading. Dig in plenty of peat, compost or well rotted organic material to improve drainage or plant into raised mounds. Plant another tree, not an ake ake. For some reason, one tree may be more vulnerable and curl up its toes and leave one either side unaffected.

Although puka are evergreen, they do shed leaves which turn yellow and eventually drop. Puka are also frost tender. If you have planted it in a frost prone area, it would be best to move the tree. Winter is a good time to lift and move it. If the soil is not well drained or you have had dry periods followed by wet it could be phytopthora and there is little that can be done to save the tree. Remove it and replant a different tree in that spot (not another puka). Improve drainage as for ake ake. Otherwise, just keep an eye on it as this may be a natural process the tree is going through — if the new growth looks healthy I would not be concerned. Protect from the prevailing wind.

Mulch around the trees with well rotted organic material to keep the soil cool and moist over the summer months. Bark, compost, decomposed lawn clippings, hay, straw, silage, untreated sawdust are all suitable.

Advice by Dr Dan Blanchon from Unitec's Diploma in Sustainable Horticulture and Bachelor of Resource Management.

Reproduced with permission from NZOOM Home and Garden content, from the previous website of  The views expressed here are not necessarily those of the RNZIH   HOME AND GARDEN   Plant Doctor Archives Main Page