AusBonsai

Hi All,

Hope everyone is well.

I have noticed most if not all my junipers going s purple type tinge over the last month. They aren't really going brown so I can't say they are dying and every other autumn and winter they've been fine. Anything to worry about? What should I do?

I've also noticed some of them - the older ones, getting really dense needles with purple type points on them? Almost like little seeds or something. Is this a maturity thing?

Some background info...

The weather has cooled in to autumn and will only get cooler
Last repot was just before spring 2019 - will repot shortly.
They spend all morning in sun and a bit in the early afternoon
They are getting good amounts of water

In colder areas, juniper foliage goes a purplish-bronze colour in winter and there are several other posts on this site that indicate frosts may play a part in the colour change.

Not very well depicted in the photos but I suspect you are just seeing the adult scale foliage on the strongest parts of the older junipers. I have similar foliage on mine. The squamata junipers are scale junipers but juvenile spikey foliage is the normal reaction to our constant trimming and pruning.

Some purple foliage through winter is normal so I would also say nothing to worry about at this stage.
Check for pests to make sure. Most juniper pests are really small and hide right down in the leaf axils so look close. Scales and mites appear to be the most common pests.
No mention of fertilizer regime in the background notes. Lack of fert could also cause purple foliage.

The dense purple bits are not clear on the photos but I suspect they could be cones so that would be a maturity thing.

I agree with Shibui. The purple bits are cones. Male, if I remember correctly.

Hi All, some more photos to look at. I almost feel some are going more yellow? It didn't happen last winter which is odd.

The photo with the juniper in the burgundy circle pot isn't as badly impacted as the others that are in the front and cop more of the wind. The back side of the big juniper in the tall part looks really good. Nice and green.

As far as actions go, any thoughts? They get plenty of sun. I was going to repot what I can this weekend.

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The really yellow one does not look good. Usually by the time a juniper gets to that color it is all over but trees have been known to return from the brink so there is still faint hope.
I assume you have checked for scale and mites?
Still no mention of your fertilizer regime. Starvation does cause yellow foliage.

It will be interesting to see what you find when repotting. I suspect some sort of root problem but symptoms are the same for both too much water and too little water so it can be hard to pinpoint the real cause.

that some will survive for you.

Had a similar problem and that was wet feet. Watering to often was turning the foliage yellow and as shibui mentioned in most cases it’s too late
Cheers RodM

Here's the photo of the roots of the big one.

I haven't been over watering. In fact there's been decent rain I've just let nature do its thing and haven't watered additionally.

The roots looked okay to me. Appreciate of course more or less pot bound? I've repotted it, fed it and watered it. Thinking not to prune otherwise it will maybe be too much for it.

And yes, no mites or pests. Fertilising regime used to be almost daily then stepped it back to weekly. We've had good rain as I mentioned, so haven't fertilised for a while now

Thoughts?

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Hi All,

Growing Bonsai requires a level of patience. It also requires dedication and care. We bonsai folk perhaps come negative when we see our plants suffering. There was a bit of that about this post, for we see yellow and we feel mellow! But alas, I buckled up, rolled up the sleeves and saved every single one of them! They are looking more and more green and looking today some early growth is appearing just ahead of spring next month.

These photos were from last week.

Really happy I saved them. The biggest one that cascades was my first ever tree. It's about 10 years old now


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Can you share what you did to hep them recover?

Sure!

First I repotted immediately to check the root structure. The roots actually looked quite healthy so my goal here was not to stress the tree out so I cut minimal roots away. One tree had some roots that suffered a bit of rot and were dead so I cut those off of course.

Next I replaced with new soil and dampened the soil with fertilised water before placing the trees back in. Once the trees were repotted I didn't prune unless the leaves were dead to make sure I didn't stress it out more. I did gamble here as some would say rid the tree of the yellow so it stops wasting energy on them. I chose not to as I figured the tree was already week and didn't need to be stressed further and second, the needles seemed to still have life in them.

Once repotted I fertilised daily for 1-2 weeks and then fertilised regularly perhaps every 2-3 days after that point. Slowly they began to turn and now they seem to be look quite good !

The root system was healthy but I feel the soil just wasn't given them enough nutrition anymore. My fertilising routine had slowed down too much, thus not compensating for the soils age.

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Good to hear of a successful outcome.
I agree with your theory that more roots can interfere with fertilizer program. I regularly have the same trouble with pines. It appears when the pot is full of roots the liquid fert doesn't have as much space to fit so less is retained. In addition any fert that was included in the potting mix has been exhausted. Usually I can change them around just by boosting the liquid feed but repotting as soon as possible makes an even bigger difference.

Many new growers find it hard to accept that repotting can actually cause their trees to grow better. We are conditioned to believe that cutting roots is bad for plants but the opposite seems to be true, at least with potted plants. Repotting with root pruning gives your potted trees more scope to grow new roots that are more efficient, gives them better air and water and fresh soil structure so growth rates generally rocket in the season after a repot.

Great work on the recovery. Hope it powers on. Top job
Cheers RodM