How to treat Carissa Desert Star with black leaves?

cranberryend

Hi all,

My Carissa Desert Star was doing fine while it was in a pot, but I planted it into the ground about 6 months, and just recently I've noticed that its leaves are starting to turn black. Can anyone advise on why that might be?

Thanks so much,

Anna

JacobZ

Hi @cranberryend,

Thank you for your question about your Carissa Desert Star plant.

I'd suggest you start by having a look at @Noelle's article How to diagnose a sick plant.

Is it possible to get a photo of the soil? If you dig around the base of the plant, is the ground sodden?

I suspect the cause of the issue is likely poor drainage due to poor soil conditions. Poor drainage can cause root rot which can manifest in discolouration of the leaves.

To fix drainage issues, you will need to aerate the soil and improve its drainage characteristics. 

Grab a hand fork and gently aerate the soil around the base of the plant being careful not to damage the roots. This will open up drainage channels and provide oxygen to the struggling roots.

After aerating, apply compost or manure to the base of the plant and mix it in. This will encourage microbial growth and beneficial insects which will dig channels and promote further drainage.

It would also be worthwhile applying a general-purpose slow-release fertiliser such as this Scotts Osmocote 500g All Purpose Controlled Release Fertiliser. This will provide the nutrients your plant needs to fight the issues its facing and thrive into the future.

Let me know what you think and if you have further questions, please don't hesitate to ask.

Jacob