Fighting soil salt toxicity

[LemonBonsai]

So ive been having a problem with all my citrus trees. They all are showing signs of salt toxicity. Yellow around edges of leaves, brown tips of leaves. I have tried flushing the soil out but it doesnt seem to be doing much. I know the best way to relieve this would be to change the soil, however since it is winter I need to wait until spring to repot them, as of now im stuck and wondering if theres any tips anybody has to fix this issue. Is there something I could add to the top of the soil and water into the pot that would help? Or is my only option to keep flushing, get through winter, and repot into a soil that has more compost in it. By the way my soil composition is about 1:1 ratio of sifted perlite and oil dry, with about 15-20% of potting soil.

Thanks!

 

[0soyoung]

any tips anybody has to fix this issue

Step #1 is to post at least one photo of what you are trying to describe about your citrus trees.


The whole thing of 'salt toxicity' is commonly called 'fertilizer burn' as ferts are salts. Root cells load minerals by making their (cellular) fluids saltier than the soil. Water then moves into the cells by osmosis. Classic 'fertilizer burn'/'salt toxicity' causes water to move out into the soil instead (because the soil is saltier).

My guess is that your trees got too dry (or were 'under-watered') when the leaves were emerging or newly emergent. Do you remember a day seeing the trees looking a bit droopy, then they perked back up when you watered? Commonly 'burned' leaf margins, such as you seem to be describing, show up days later.

 

[Wires_Guy_wires]

Rain water and distilled water can help.
But I agree with naughtsoyoung that a photo would sure help.

 

[Tums]

With so little organic material I'm surprised your soil could even hold onto enough fertilizer salts to cause burn. It could be a lot of things, like soil temperature, so a photo would be helpful.

 

[HorseloverFat]

With so little organic material I'm surprised your soil could even hold onto enough fertilizer salts to cause burn.

THIS is what I was thinking, as well.... my citrus From seed (that I was able to establish here)... only “throws fits” when I mess with the roots... I’ve given it acid fert, more lime fert. Tried JUST foliar... nothing really CHANGED in the trees response to the minerals/nutrients.... it seems to “not care”.

When were they repotted last?

How did the roots look?

Citrus are like Punicas.. in that they SEEM to “withstand” drought.. when truth be told.. they HATE it.. and are just strong, genetically... under-adequate watering led to many weak Punicas and Citrus.. once I changed their watering schedule.. it was like a night and day difference.

Someone mentioned something about pictures..

 

[LemonBonsai]

Ok so I got this weird feeling that I should post a picture heres some pictures, some are from leav
es that are pretty old, others are leaves that are very new and just starting to show signs of salt burn. I dont fertilize very often, i also dont let citrus dry out very much, i find they respond well with never ever letting them dry so I dont let them dry out.



Repotted last spring, roots looked great when I repotted.



So the first picture is a picture of the salt burn I was dealing with last year, newer leaves on this tree are good, but worried to not let the new leaves be affected from the salt burn, second picture is again older leaves from last year that i am trying to prevent further damage to newer leaves. The third picture is newer leaves from another planting. I did flush this plant yesterday, so we will see what happens but again I dont let them get bone dry or anything, and I dont fertilize them very much. Infact judging by the color of them, i would say im underfeeding them, i just dont want to overdo it.

 

[Bonsai Nut]

Tell us about your water. Where is it coming from? Do you know the pH?

 

[LemonBonsai]

Tell us about your water. Where is it coming from? Do you know the pH?

I dont know the PH, but it is Reverse Osmosis water

 

[HorseloverFat]

I dont know the PH, but it is Reverse Osmosis water

I’m sorry, friend. I have never seen this.

(Everyone gonna act like hearing “reverse osmosis” DOESN’T remind them of “Osmosis Jones”?... ok)

 

[HorseloverFat]

underfeeding

Hmmmm...

 

[Bonsai Nut]

I dont know the PH, but it is Reverse Osmosis water

That confirms that it probably has nothing to do with salt poisoning, since RO water removes almost all salts, and would flush fertilizer salts out of the soil.

pH is critically important when it comes to the ability of a tree to update vital minerals. The photo of your chlorotic leaves suggest (to me) iron and manganese deficiency due to high water pH. You need to test your water because if it comes from a public water source I will almost guarantee you it is alkaline (high pH).

 

[Tums]

Shouldn't RO remove any calcium or magnesium from the water and turn it to a roughly neutral ph? Based on the pictures of interveinal chlorosis and the earlier comment where OP indicates they don't fertilize very often yet water frequently, my guess is the trees need more fertilizer, particular with the minor nutrients such as iron, zinc, manganese.

 

[Bonsai Nut]

Shouldn't RO remove any calcium or magnesium from the water and turn it to a roughly neutral ph? Based on the pictures of interveinal chlorosis and the earlier comment where OP indicates they don't fertilize very often yet water frequently, my guess is the trees need more fertilizer, particular with the minor nutrients such as iron, zinc, manganese.

Yes you are correct and I am wrong.

For some reason (perhaps due to Friday night) I started confusing my tap water knowledge with my reverse osmosis knowledge. Reverse osmosis water should be neutral to slightly acidic.

 

[River's Edge]

I dont know the PH, but it is Reverse Osmosis water

You should check the PH, reverse osmosis quality is highly dependant on the source and how well the equipment is maintained. Deficiency can be the result of PH out of range low or high. The accumulation of apparent salts is a clear flag that something is off, particularly if you fertilizer regime is low to moderate.

 

[0soyoung]

You mention nothing about fertilizers, @LemonBonsai, and the leaves look to be somewhat chlorotic.. Iron deficiency is the classic cause of chlorosis. Iron sulfate is the usual remedial source. You can get some at any garden center or you can get it from iron supplements intended for human consumption. If you've got the supplements, you can dissolve a pill/tablet/capsule in a glass of water and then spray that on the leaves. They will green up within a few days if it is due to iron deficiency and, if so, you can then add iron sulfate to the soil where is will do more lasting good.

Magnesium ions are in the core of chlorophyl and a deficiency of them will cause similar chlorotic appearance. Epsom salts is magnesium sulfate. Test dissolving a pinch in glass of water and if a positive response put a few pinches on the substrate/soil for lasting good.


If foliar applications do nothing, then you can mark off iron/magnesium deficiency as possibly responsible for your trees' problem.

 

[discusmike]

Reverse osmosis water has no minerals or trace elements in it, I use for my aquariums and the ph is 4.0, maybe add some tap water to the ro water, get a ph meter for aquariums, and check your ph, your trees are probably deficient as noted

 

[MichaelS]

Classic magnesium deficiency but you should feed everything and a wide rage of feeds including organic. Just make sure than none give an alkaline reaction.

 

[River's Edge]

Reverse osmosis water has no minerals or trace elements in it, I use for my aquariums and the ph is 4.0, maybe add some tap water to the ro water, get a ph meter for aquariums, and check your ph, your trees are probably deficient as noted

The PH will be dependant on the source and the filter screens use to produce the RO. Often water sold as RO is variable in parameters. When I produced my own for my aquarium system it was always important to monitor the output to determine when filters needed to be cleaned or replaced. My sytem produced RO water for 330 aquariums in a large retail setting. It was important to measure and balance with reconstitution for best results.

 

[Lorax7]

Shouldn't RO remove any calcium or magnesium from the water and turn it to a roughly neutral ph? Based on the pictures of interveinal chlorosis and the earlier comment where OP indicates they don't fertilize very often yet water frequently, my guess is the trees need more fertilizer, particular with the minor nutrients such as iron, zinc, manganese.

Because of the lack of carbonate hardness, the pH of RO water may be unstable. The same is true of distilled or deionized water. The buffering capacity has been removed, so whatever trace basic or acidic salts remain are able to easily tip the pH balance to extremes. It can change over time during storage too as dissolved gases equilibrate with the surrounding air and as the solubility of gases changes with temperature. For example, dissolved CO2 will decrease the pH. The easy thing to do would be to get an aquarium pH test kit from your local pet store as well as pH Up and pH Down to adjust the it accordingly.

I think it's very unlikely that this problem is caused by salt toxicity from excess fertilizer.

 

[Firstflush]

How often do you water? Citrus like it on the dryer side. Yellow leaves on citrus often indicate too much water. If you say you aren’t fertilizing that much, likely not fert burn or salt build up.