AusBonsai

Hey guys,

I put a post up a little while ago asking about issues that I was having with my shimpaku tips dying back and the advice I got was juniper tip blight. I’ve been treating them with mancozeb every 14 days. The issue is worsening and spreading to other shimpaku. At this stage I can’t seem to stop whatever is going on so thought I’d ask again.

At this stage my really good stock has become infected and I’m nearly ready to give up. I can’t see any pests at all. My mugo pines are dying as well as my hinoki.

The junipers are in full sun. Yes it’s been hot in Perth but, they’re in the same position as last year so I don’t know if that’s it.

The mugo and hinoki are under shade cloth. I’m unsure if it’s too much/too little water, a pest or disease.

Any help would be great. About to give up at this stage, I’ve had such bad luck and spent a lot of money on the plants. Really disappointed and am unsure where to turn.

Thanks

New tips on the junipers seem to be fine. Mostly affects older growth.
My best guess based on the symptom in all the species would be dehydration.
Shimpaku do like sun but they do NOT like getting dry.
Have you changed potting mix since last summer?
Any change to watering frequency or timing since last summer?
How long since the older trees were repotted?

One problem with diagnosing dehydration is it can be caused by not enough water or too much water.
Symptoms often don't show up for several weeks in conifers. By then we've often forgotten about those few hot days or the day we forgot to water or did it in a hurry.
Too much water causes roots to rot. Then the trees cannot take up enough water and dehydrate even though the soil is wet. Diagnosis is by knowing how wet the potting mix has been over several months. Tip a few plants gently out of the pots and check the root ball for healthy white root tips. Sometimes, in bad cases, the root ball will smell unpleasant.

I don't have a lot of direct experience with Hinoki. They don't do very well here so I no longer bother with them. They don't seem to like hot weather much.

Thanks for the reply Neil! So, I have the changed the soil on some, not all. The ones that haven’t been changed are more affected than the ones that have.

The mugo, I just don’t know. I just can’t seem to get them to survive. They always slowly die back from the tip of the needle all over until the plant is gone.

The hinoki I thought perhaps I had over watered. The thing is, one of them is completely fine with no dead tips at all. The one that is dying of course is the cultivar with the really tight nice dense foliage

I lost 3 cryptomeria this year from the tips just slowly dying too hence, why I was thinking disease.

I did find 2 of those tiny red bugs but, I don’t think they’re the spider mites. There’s just no webs or any other signs.

The junipers did have some white tips. Not many but the pot is probably a little too full atm and needs a trim.

With that said, is it ok to repot them in their current state? The soil is dry in spots so I think it has become a little hydrophobic. I worry it will kill them off. I did repot one a little while ago and the issue did worsen. That said I guess they do grow slowly so it may be some time before it starts to recover?

Thanks for your help!

What kind of fertiliser are you using?

I’m using macrocote I think it’s called, some seamungus pellets too.

Hope that helps!

The new photos showing roots are not encouraging as there are few white tips showing. Usually an indication of some problem but that can be too dry, too wet, pest or infection killing the roots so doesn't help find the problem. Having said that I just checked some of mine and I found a range of different root balls in the pots. The tree was pruned hard in spring and has probably been dry a few times through spring and early summer. Both those factors will have killed some roots. The tree seems healthy enough and should recover.
I've noticed that, in general, the longer trees are in pots the harder it becomes to water properly as the roots fill the soil spaces and prevent water from penetrating into the centre of the root ball. Each day the roots take water out but less gets in until there's just not enough water to last all day. The fact that recently repotted trees seem to be less affected may support this theory?
In the new photos notice you have the junipers in pots inside larger pots. That usually gives more space for water and allows the trees to last longer in hot, dry weather and also helps to protect from excess heat on the pots. Not sure if those trees have roots out into the extra pots yet to take advantage of the extra space?

You mention the soil is dry in spots which leads us back to underwatering. While I do emergency repots when necessary I'd be reluctant to repot these during hot weather except as a last resort. Look for ways to water more effectively. I'd try soaking the pots initially to get the root balls properly wet. Where pots are reluctant to get properly soaked by normal watering I've soaked them in water once a week to make sure the roots are well watered at least occasionally.
Also try better watering practice if not already doing so. Dry potting mix is notoriously hard to rewet. The first water just runs around and through without properly wetting the mix. A second watering allows the water to penetrate more deeply. I've heard some Japanese water 3 times to allow proper water penetration. In hot weather I often water all the pots then go back and water them all again to allow the water to soak in better.

The potting mix appears to be in good condition, at least in the pots shown, so no need to repot on account of broken down potting mix.

I also see that the pots are sitting on the ground. That's another thing I have found to cause problems but usually because they don't drain properly rather than making them dry.

Red bugs could be red spide mites or 2 spotted mite which don't tend to make as much web as some other mites but there's other red bugs that are not harmful to the plants. You'd need to look much closer to see whether there are enough to be causing the problem and what it is. A good magnifying glass of some sort is needed to see most mites as they are usually too small to see properly with the naked eye.

Sorry I can't be more definite but, given the symptoms, time of year and location I'm still leaning toward dehydration being the problem.

Thanks for the in depth reply Neil. I’ll definitely have to go back over the pots with water for a good drink. I’ll soak them this morning and hopefully get the water right in there.

In regards to repotting, when would be a good time? Is there a time in autumn that would suit? Spring is a long ways off! I’ll get ahold of a magnifying glass for a closer look at the bugs. As I said I only ever notice one or two and on closer inspection I can never find any. Tried the “shake over paper” trick too which turned up nothing.

I wouldn’t be surprised if it is a bug/disease seeing I’ve had scale, weeding caterpillar, mealy bugs and thrips all in one season this year. The joys of the city

Hopefully we’ve got the problem! I would assume it’ll take a while for regrowth etc?

Thanks mate, I greatly appreciate your help as always

Hi Mickey

Coincidentally or not I've got some shimps that are showing similar problems. Looking a bit "how ya going mate how are ya". The progress of the foliar browning seems in line with what treeman described in this post:

"Also possible.... Cercospora Twig Blight:
''This disease is caused by the fungus Cercospora sequoiae var. juniperi. It begins by infecting the oldest needles that are located on the lower branches, inside of the plant. As disease development progresses, the needle browning spreads upward and outward. Branch tips usually remain healthy and green. Needles of spur branches turn brown and die usually in the late summer, leaving a plant with an inner crown devoid of foliage. This disease is sometimes confused with mite damage''."

While he recommends sacrificing affected plants on a pyre, I'm gonna stick it out, obviously keeping them here in home quarantine while trying everything possible- fungicidal sprays and drench, root check, early Autumn repotting, hard cutback. I'm determined to learn from it. Here's an affected specimen that seems to show healthy roots:
And to demonstrate that this hobby is sometimes two steps forward, one step back or vice versa, here's a tray of cutting I took on Australia Day that got roasted on our 43 degree day, under 50% shadecloth and a bench. From it I'm grateful for the new knowledge that on such days I need to take tubs of cuttings into the house.
Before, like a mini pine plantation: If you work out how to quit the hobby let me know.

I think it’s a combination of problems. Some of my trees have occasionally, as compared to your images, experienced similar fate…

My problem is;

1) mix is too organic
2) i miss a water or two
3) the fertiliser breaks down quickly and dumps too much at once into soil
4) the trees don’t have enough fresh air flow (because of bench crowding)
5) I overpot

Don’t give up. Some species just don’t mesh with particular growers.

BirchMan wrote: ↑February 4th, 2024, 1:43 pm Hi Mickey

Coincidentally or not I've got some shimps that are showing similar problems. Looking a bit "how ya going mate how are ya". The progress of the foliar browning seems in line with what treeman described in this post:

"Also possible.... Cercospora Twig Blight:
''This disease is caused by the fungus Cercospora sequoiae var. juniperi. It begins by infecting the oldest needles that are located on the lower branches, inside of the plant. As disease development progresses, the needle browning spreads upward and outward. Branch tips usually remain healthy and green. Needles of spur branches turn brown and die usually in the late summer, leaving a plant with an inner crown devoid of foliage. This disease is sometimes confused with mite damage''."

While he recommends sacrificing affected plants on a pyre, I'm gonna stick it out, obviously keeping them here in home quarantine while trying everything possible- fungicidal sprays and drench, root check, early Autumn repotting, hard cutback. I'm determined to learn from it. Here's an affected specimen that seems to show healthy roots:

IMG_2883.JPEG

IMG_2884.JPEG

And to demonstrate that this hobby is sometimes two steps forward, one step back or vice versa, here's a tray of cutting I took on Australia Day that got roasted on our 43 degree day, under 50% shadecloth and a bench. From it I'm grateful for the new knowledge that on such days I need to take tubs of cuttings into the house.

IMG_2885.JPEG

Before, like a mini pine plantation:
IMG_2880.jpeg

If you work out how to quit the hobby let me know.

Thanks mate, I appreciate it. It’s a little disappointing to spend so much time on them and then have this issue but, I guess it is what it is. I just have to harden up haha.

Is there a road to recovery if they do have the twig blight? I better move them away from my healthy plants! I just wasn’t sure what it was. I think Neil may be right with the hydrophobic soil/hot temps and perhaps it could be the fertiliser too. I’ve noticed some of the macrocote has broken down and is crumbly early.

More airflow couldn’t hurt either. They are a little tight.

Can you suggest a good fertiliser?

For soil the main affected ones are in an organic mix that I just didn’t have time to repot. The others are in a perlite and coir mix which they seem to really like.

I had no issues last year at all and after quite a few disasters this year, I’m struggling to keep on it. I’ll keep trying!

Cheers mate

Don't be too hard on yourself. It's very common to lose plants like this early on. Things like this can still happen to anyone, but over the years these sort of incidents should become less frequent as you learn more about what works best for you, your location, and your methods.

Hopefully you don't give up on bonsai. I wish you better luck moving forward

Definitely disappointing, and for me it's much more common to have these rapid hard to explain declines in conifers than any other class. I only persist with them because they have some of the biggest upside if you can get it right.

I don't recall ever bringing a conifer back from this kind of state. They tend to just keep declining, but that's just my experience. It's definitely gutting but it's getting a little less frequent for me as my practices improve.

I like organic ferts so everything gets weekly or fortnightly half strength doses of Powerfeed from late winter til December. Then i switch to blood and bone and for the conifers Troforte slow release.

I also find perlite and coir/Baileys premium makes a good mix for conifers in the Perth climate. So I might start gravitating towards that. Interesting it's also what Eric Schrader has recommended for grow-on stock in San Fran.

cheers

BirchMan wrote: ↑February 5th, 2024, 1:36 pm Definitely disappointing, and for me it's much more common to have these rapid hard to explain declines in conifers than any other class. I only persist with them because they have some of the biggest upside if you can get it right.

I don't recall ever bringing a conifer back from this kind of state. They tend to just keep declining, but that's just my experience. It's definitely gutting but it's getting a little less frequent for me as my practices improve.

I like organic ferts so everything gets weekly or fortnightly half strength doses of Powerfeed from late winter til December. Then i switch to blood and bone and for the conifers Troforte slow release.

I also find perlite and coir/Baileys premium makes a good mix for conifers in the Perth climate. So I might start gravitating towards that. Interesting it's also what Eric Schrader has recommended for grow-on stock in San Fran.

cheers

Well that’s a real bummer. The majority seem to be suffering from it. I’ll try but, it doesn’t sound like they’ll make it. Damnit. My kunzea died, woolly bush dead, lepto dead, mugos dead, hinoki, azalea, banksia… the list goes on. Not sure what’s going on. I research my plants and follow advice I have had every kind of pest this year though.

Those shimpaku are so disappointing. They cost a lot. I love me a good shimp bonsai. Maybe I should appreciate them from afar haha.

At least the Mel’s are doing ok.

I guess my biggest frustration is that more than enough people do grow them successfully in Perth so, I don’t know where I’m going wrong.

Thanks for the help as always!

Fertiliser

I use rooster booster, powerfeed, nitrosol and blood bone.

I’ve started using the blue packet osmocote as well.

Mix

I’m adding lots more inorganic to my mixes with conifers - scoria, coarse sand, pumice, zeolite in any combination.

Watering

I’ve also found jet streaming water through the foliage of junipers and pines helps remove this white tissue like growth that pops up. It looks like when you leave tissue in your clothes and put it in the wash. With time it grows and greeness goes if left unattended.

I also water the benches after reading that it helps with humidity.

Mickeyjaytee wrote: ↑February 5th, 2024, 6:28 pm Damnit. My kunzea died, woolly bush dead, lepto dead, mugos dead, hinoki, azalea, banksia… the list goes on. Not sure what’s going on. I research my plants and follow advice I have had every kind of pest this year though.

Sounds like a watering issue. Plants don't just die. I grow 100's of plants for Bonsai stock. Well over 90% of all loses were from under watering. As shibui mentioned above, Confiers can take quite some time to show issues. Even some natives seem to die suddenly a fee days after drying out. Usually there are signs of wilting on broadleaf trees. Pests can also be more of a problem when tress are stressed.

I'm watering twice a day quite frequently at the moment, sometimes some things get 3 waters. Days often in the low to mid 30's with high humidity. Windy days I have to be extra vigilant. I imagine the hot dry conditions of Perth will dry things out very rapidly, especially, as shibui mentioned, when the mix gets dry and becomes hard to rewet. One trick I have learnt to check is get used to the weight of a pot. If it feels very heavy, the mix is probably saturated. If it feels extremely light, it is probably bone dry. Water it well and check again. If it still feels quite light the interior of the mix is probably still sry. Give it a soak for about 1/2 hour.