Q.Crown of thorns
We have recently planted crown of thorns in our back yard. When planted the leaves had dark spots and leaves turned dark, several leaves had holes and many leaves turned yellow. This was happening before I have sprayed twice a 3 in 1 product twice but did not help.
Hope you can help.
Certified GKH Gardening Expert
This appears to be something of a fungal issue, and more than likely a pH issue, also. Apply wettable sulphur to the soil, to control the fungus. Add dolomitic lime to the soil to correct the pH. Here is an article for more information on the plant: https://www.gardeningknowhow.com/houseplants/crown-of-thorns/growing-crown-of-thorns-outdoors.htm