Lilly Pilly die back. Verticillium Wilt?

[Jackuza96]

Our Lilly Pilly trees started to drop leaves in November.

Leaves turned yellow and started to drop. Symptoms started with one of the trees then suddenly all the tree along the fence

started to show the same symptoms as if it was spreading.

During the winter time I water the trees once a months and let the rain water do the rest of the job.

Once the temperature started to rise I began deep watering twice a months plus rain water.

Gave some fertiliser(Dynamic lifter) to the trees in October and also gave Seasol liquid in September and October.

I dug up one of the trees to see the roots. Roots were moist and dark but did not have any rotting smell.

It didn't look or smell like a root rot so I increased the watering amount to the rest of the trees.

No signs of recovering. Only getting worse.

As I was pruning off the dead branches I've noticed dark marks in the stem. Could it be Verticillium Wilt??

Will they recover from current condition?

05 Nov leaves started to dropDie back from topLeaves easily come offRed Brown leavesChecking the rootsMoist but no Smell of rotting25 Nov all of the trees along the fence are like thisVerticillium Wilt??Verticillium Wilt??Verticillium Wilt?? Very dark.

[BradN]

Hi @Jackuza96, and welcome to the Bunnings Workshop community. It's great to have you here.

I'm sorry to see that you're having such trouble with your lilly pillies. Our Bunnings D.I.Y. expert @EricL will be back on the site later today, and in the meantime I'll also tag horticultural experts @Noelle and @Adam_W to see whether they can offer any advice.

I'm sure they'll find the photos you've supplied very helpful.

Is your soil very hard or compacted or full of clay? I'm intrigued by the shape of the rootbball of the plant that you've pulled out.

It looks as though the plant has had trouble putting out roots beyond the diameter of the pot that it came in or the hole it was planted in, and has mainly grown new roots through the very top of the soil. If it has been unable to develop a healthy rootball that might have contributed to its problems. Hopefully one of our more knowledgeable members can advise.

Brad

[EricL]

Hello @Jackuza96

Looking at the photos you posted, it looks like part of the roots are black but the outer roots look fine. Verticillium leaves a very recognizable mark on the inside of the stem of the tree and looking at those stems it might be just that.  I'm sorry to be the bearer of bad news, but there is no effective treatment for verticillium wilt. Your best course of action is to remove the infected tree, do not mix it in with your compost or use any part of it in your garden. It's best to put it in the bin so that the fungus does not spread further.

I suggest solarizing the infected area to reduce the amount of fungus in the soil. Unfortunately, there is no effective method of removing all the fungus in the soil. 

If you need further assistance, please let us know.

Eric

[Jackuza96]

Thanks for getting back to me.

Would you be able to recommend a type hedge or screen plants that are resistant to Verticillium Wilt? 

[EricL]

Hello @Jackuza96

Allow me to do a bit of investigation regarding what hedge is not susceptible to Verticillium Wilt. As soon as I have more information I'll get back to you.

Eric

[cjp76]

Any updated on this topic @EricL or @Jackuza96 ?

I've also had some mangolia screening trees die from Verticulum wilt and would like to replace the screening with something resistant?

What did you end up going with @Jackuza96 ?

[MitchellMc]

Welcome to the Bunnings Workshop community @cjp76. It's sensational to have you join us, and many thanks for your question about plants resilient to Verticillium wilt.
 

There isn't a hedge that is entirely immune to Verticillium wilt, but a couple known for being highly resistant to this soil-borne fungal disease are Boxwood (Buxus spp.), which is highly resistant to Verticillium wilt. These plants are evergreen and commonly used for hedging, and Photinia (Photinia spp.), which is commonly used in hedges, and some varieties have shown good resistance to the disease.

To minimise the risk of Verticillium wilt, avoid planting hedges in areas with a known history of the disease, and practice good garden hygiene by removing affected plant material and improving soil health.

Please let me know if you have any questions.

Mitchell
 

[cjp76]

Thank you @MitchellMc - great advice.

Any specific tips for improving the soil before we replant? Not planting any screening is not really an option Hence my desire to get something resistant as I assume verticulum wilt will hang around in the soil for a while.

What about castwellan gold (connifer)? I've read all connifers are resistant also and this one is good and fast growing.

[MitchellMc]

To improve the soil before replanting @cjp76, you'll want to focus on boosting its overall health to minimise the risk of Verticillium wilt returning. Start by removing any infected plant material and working in plenty of organic matter, like compost or well-rotted manure, to improve soil structure and drainage. You could use something like Seasol Earthcare Super Compost or Dynamic Lifter Soil Improver & Plant Fertiliser. Applying a bio-fungicide like Yates Anti Rot can also help protect your new plants.

As for the Castlewellan Gold conifer, you're absolutely right. Conifers, including Castlewellan Gold, are generally resistant to Verticillium wilt, making them a solid option for your screening. They’re fast-growing and provide good coverage, so they should work well for you. Just ensure the soil is well-prepped, and avoid waterlogging as conifers prefer well-drained conditions.

Mitchell

[Jackuza96]

Hi @cjp76 

I’ve planted Tiger grass, which is resistant to the disease. It performs very similarly to bamboo but is non-invasive. It also grows very fast, making it an excellent choice for screening plants.