How to treat Pencil Pine that has yellowed?

[Sal15]

Hi all, we had 12 of these pines planted in April, one of the best growing pines has suddenly yellowed and evidently has not survived. They all have irrigated and ample sunlight. Would be grateful for your thoughts/suggestions as I worry another pine may be

suffering the same fate.

Community manager's note: Check out How to diagnose a sick plant for expert advice. 

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[MitchellMc]

Welcome to the Bunnings Workshop community @Sal15. It's amazing to have you join us, and many thanks for your question about your sick Pencil Pine.

We'll need to establish what has changed that would contribute to your plant's ill health. How's the weather been in your area, and how long does it take the soil to dry out after watering or rain? What type of soil is it, and did you plant over a clay layer?

If you've been experiencing some wet weather or you've planted over a clay base, you could have waterlogged soil, which would be a reason for the sudden change in your plant's health. Also, what's your watering regime like? Are you ceasing to water when it has rained? If you haven't watered recently and it hasn't rained, stick your finger in the soil and see how damp it is. 

There's a chance that some type of fungal disease that is promoted by moist soil or insect infestation could cause this issue, but I'd be keen to hear more about the soil saturation levels before trying to diagnose other potential issues.

Once you've provided some information on your watering regime, soil type and weather events, I'll tag in some of our gardening experts to assist.

Mitchell

[Sal15]

Hi Mitchell, thanks for getting back to me.

The weather has been wet but we have adjusted the irrigation for this. I'm not sure about the type of soil or clay layer as a landscaping company did the planing. We did check the soil and thought it not to be too dry or too wet.

There was a massive scale infestation of the pines that we only noticed 6 weeks ago. We treated with 2 treatments , 7 days apart with botanical oil. It seems to have worked as there are only a few scale remaining. 

[EricL]

Hello @Sal15

It's good to hear that you've got that scale infestation under control. Have you placed any fertilizer in the soil in the last three months? Did the landscape company mention anything about putting in organic compost? The only other thing that comes to mind is the tree is not getting enough nutrients in the soil. 

Eric

[Sal15]

Thanks for your input all.

The horticulturalist that planted them came by and was unsure why the pine had died. He pulled it out and thought the soil and roots looked fine. 

There have been no added nutrients since planting.

Unfortunately it appears that most of the 12 pines are suffering the same fate. First their top stems flail out , then the tree starts to yellow.

We really want the pines in that area for privacy and are worried about re-planting give they all seem to be dying now.

[EricL]

Hello @Sal15

I suggest checking the pH levels of the soil with a Manutec Garden Care Products Soil PH Test Kit. A neutral soil pH range between 6-7 is most effective for the uptake of nutrients in plants. Highly acidic or highly alkaline soil conditions lock up nutrients in soils and make them unavailable for plants to absorb.

If you need further assistance, please let us know.

Eric

[Sal15]

Hi!

This forum has been really helpful with my pencil pines that are really starting to flourish with the warmer weather. However some new growths near the top of tree turn yellow then stop growing. 

I manually water the trees every 2-3 days (have checked that the soil is not too damp with water gauge)

I used dynamic lifter 3 weeks ago.

I use seasol every 2 weeks.

Overall the trees seem to be doing well - but wanted to make sure I am not doing anything wrong. Any ideas?

I've attached 2 photos of the problem and then a photo to just show the general overall good health of trees. Thank you 

[MitchellMc]

Hi @Sal15,

I wouldn't be overly concerned with this new growth as the overall health of the trees is good. If all the new growth starts dying off, that could indicate an issue. 

Instead of using the water gauge, which can be quite temperamental, stick your finger in the ground. If the soil is wet or damp, don't water; if it's starting to dry out, you can water.

Also, I'm not sure how much attention you have been paying to the new growth, but I'm under the impression that the new growth should look yellowish and then turn darker green as it ages. 

Overall it sounds like you are doing a great job.

Please let me know if you have questions.

Mitchell