How to fix disease and discolouration of Banksia plant?

[amichaelmedia]

Hey all

Planted these banksia sentials under 6mths ago. They have had spider webs on them recently and some discoloration? How to fix?

I've applied some eco oil for Webbs and seasol for discoloration

 

 

 

[EricL]

Hello @amichaelmedia 

Thanks for sharing your question about your banksia plant. In order for us to give you a better diagnosis, can you please tell us how often you've been watering the plant and has any insect or fungus been attacking it.

One of the common signs of dehydration in plants is that the tips of their leaves start to turn brown. However, you also get the same symptoms when the roots are being attacked by black root rot.

Would it be possible for you to dig near the plant to check the condition of its roots? This will tell you if the soil is waterlogged or if the plant is not getting enough water. 

Any other information you can share about what has been happening around the plant will help us identify the probable cause of its condition.

Eric

[amichaelmedia]

After establishing plants ... Watering every fortnight. 

Insects found are little spiders or mites.

[amichaelmedia]

Ive also got this bankia in a pot as a feature and it hasn't grown much over summer. It has leaves dropping and looks dry though I have been watering. It also has mites/spiders that I have used an ecooil on to deter.

Advice?

[MitchellMc]

Hi @amichaelmedia,

Please check the soil on the banksia sentinel and ensure it is drying out between waterings. Perhaps it's planted on a clay base, and the water is not draining away from the roots adequately. It is more likely to be an issue with wet roots than not getting enough water.

For your other banksia, once again, you need to check that the soil it's in isn't remaining constantly damp. Once established, Australian natives can go for months without rain before needing additional water from us. However, if planted in a poor draining mix or on clay, they can start looking sickly within a few weeks if their roots are saturated with water. How often have you been watering and does the pot have good drainage?

Mitchell

[amichaelmedia]

Monthly and not at all since autumn

Pot drainage non existent unless it's on the very bottom. And I can't see it and it sits on a paver

[EricL]

Hi @amichaelmedia 

In regards to the potted plant is it possible for you to tilt the pot at 45 degrees to check if the drain hole has been blocked? If it has, it's important to remove any blockages in order to allow the water to pass through. Trapped water in the pot will soak the roots which is not good for the plant.

Have you applied any fertilizer to either of the plants? It's possible that the soil in the area might be lacking nutrients which is affecting your plants health. I'm afraid that Seasol is not enough to support the plants needs as it is only a tonic. 

I propose adding Yates 17.5kg Dynamic Lifter Organic Plant Fertiliser and Soil Improver. It releases nutrients slowly, encourages earthworms and beneficial soil micro-organisms.

Please remember to wear personal protection such as gloves, goggles and a mask when handling garden fertilizer.

Eric

[chelated]

Is that a Callistemon? Looks like the leaves of one and the end of a little bottle brush seed near your hand, but I could be mistaken. If it is a bottlebrush, depends what kind it is when it has its growth spurts. They are picky about soil and light and need lots of room for roots, so you’d be wanting a pretty big pot with excellent drainage. The tree looks fairly mature in the photo so it may be too late to transplant it out to a raised garden bed which gives roots time to establish in good soil before hitting clay or whatever the substrate is where you live. 
Angus Stewart has an amazing book on creating an Australian Garden. Don’t give up. Read his chapters on soil, they are fascinating and do all the experiments he suggests to know your soil. It will take a few years of composting to get low phosphorus  humus that you can use to grow. Once the plant is in good soil, it can withstand all manner of mistreatment. Soil is key. Try another soil conditioner at Bunnings  like Eco something Amino Grow https://www.bunnings.com.au/eco-organic-garden-1l-eco-aminogro-concentrate-liquid-organic-fertiliser...

get some worms in the pot to help aerate with some newspaper to read and hessian to sit on. Amino grow helps you get beneficial microbes. Store bought potting mixes are generally rubbish and you are better making your own. There’s heaps of info online about what you need and don’t need. Good luck! 

[chelated]

Suggest iron deficiency. Something in the soil is preventing the uptake of iron or the soil is iron deficient. See how you go correcting it. Also useful to buy a little kit to test the ph of the soil and make sure it’s not too alkaline 

[MitchellMc]

Welcome to the Bunnings Workshop community @chelated. It's sensational to have you join us, and many thanks for jumping into the discussion.

Let me mention @amichaelmedia so they are alerted to your response. I trust they'll appreciate your assistance.

We look forward to hearing all about your projects and plans around the house and garden. Please feel free to reach out anytime you need assistance or have something to share with the community.

Mitchell