Don’s Expert Answers: Jacaranda tree with yellow / brown leaves and leaf drop

Question From:
in Army Bay, Auckland International

Nature of problem:
Jacaranda tree with yellow / brown leaves and leaf drop

Type of Plant (if known):

Symptoms of Plant Illness (please try NOT to diagnose your problems yourself):
Hi. I planted a Jacaranda tree just over three months ago into the back garden. The top half of the tree looks to be growing great but the bottom half is a different story. This half has yellow leaves that drop from the branch before the branch drops off altogether. There is also what looks like a scratch mark to the base of the trunk. Hopefully the photos attached can show this.

Soil Type (e.g. sandy, clay or loam) OR Potting Mix Type:
Planted using garden centre recommended pitting mix. Existing soil is clay which I removed as much as possible (at least twice the root ball all round).

How often do you water the plant:
We’ve had a very dry summer here so have been watering probably every couple of days for a couple of minutes with a hose. I also use a moisture meter and it always seems to indicate dry soil to the immediate roots, but wet to surrounding area. Suspect this is due to the clay in the soil.

How many hours of sunlight does the plant get each day:
Probably about 6 or 7

How long since you planted it:
Three months.

Have you fertilised? If so, with what and when:
No, other than the original planting mix from the garden centre.

Is the plant indoors or outdoors:

Is the plant in a pot or in the ground:

What other treatments have you given the plant:

Upload photo if available:

Other Comments:
I’m at a bit of a loss here. I suspect I’m either over or under watering but am not sure what to do now for the best. Any help / advice appreciated.



I don’t like the look of the lower trunk of this Jacaranda. Can you check to see whether something is tightly tied around it near ground level? If there is, pls remove it. I am inclined to agree with the moisture meter: dry roots are the problem. Potting mixes can dry out and become water-repelling. If this happens, your watering is useless. Buy a horticultural wetting agent like Seasol Super Soil Wetter. Take the nozzle off the the hose and, on full bore, push the hose into the soil a bit deeper than the root ball. Flood the tree for 15 minutes, while keeping the hose in the ground. You can remove and re-plunge it repeatedly into the soil if possible. Lastly, mix the wetting agent with water and add this to the soil around the plant. Good luck,