New Amur - Iron Chlorosis?

[Forsoothe!]

Everybody should own a small bag of Aluminum Sulfate which is useful because it is easy to use broadcast on the soil. It moves pH down which is helpful to iron uptake. Also, Epson Salts are handy and a bag of that should be in everyone's inventory. Cheap and easy to use is useful to greenhorns & experts, alike.

 

[0soyoung]

My amur leaves are quite red when they emerge. Then they look chlorotic, Then they turn solid green in full-ish sun. I've also grown them as a landscape tree and they are indeed very susceptible to chlorosis.

Everybody should own a small bag of Aluminum Sulfate which is useful because it is easy to use broadcast on the soil.

I've never used aluminum sulfate - only iron sulfate which is sold under the brand name 'Ironite greener' (not the fert the company has since also marketed). One can also get as a dietary supplement ('iron') that can be dissolved in water and applied as an foliar spray to test for chlorosis (leaves will green much more quickly).

Ironically () chlorosis is usually due to iron deficiency because the soil is too alkaline. Iron is just part of one of the thylakoid enzymes. Magnesium (as in Epsom salts) is at the heart of PSII, but Mg-deficiency rarely is the cause of chlorosis, but it definitely affects the vibrancy of leaf color.

 

[Trenthany]

These soil chemistry discussions always fascinate me.

 

[Cadillactaste]

Black spot is rapid in my area right now. Anything in the ground has it unless its been treated. Cosmetic that isn't a big deal. Make sure to tidy the pot as the foliage drops.

When my trees are really pale. I put a pinch of Epom salts on the top surface of the pot so it gets treated for a few days when watered. In case of a nutrient lock. Then...follow up with ironite once it no longer visible.

Cool tree...common issues. Next spring you won't even know it.

 

[BuckeyeOne]

It seems that Dave is struggling with the heat this year.
I received a Zelkova with some of the same problems.
I'll try and post pictures later.

 

[whfarro]

I would use some Ironite. Check the ph of your water. Amurs should be very dark green this time of year. Brilliant red during autumn.

 

[Trenthany]

I’m working through some fertilizer cakes that came on the soil. I can scoop up the rest of that and switch to a high N fertilizer or wait until the end of the month when these should be fully dissolved and then make the switch.

Both? Just add some as a boost to what they’re getting.

 

[leatherback]

Both? Just add some as a boost to what they’re getting.

Yup. Mine do not need to finish their plate before they get dessert!