Lemon Tree Question

[Bonsai Nut]

I’ve got a little lemon tree and pH 7.6 water. It did ok this year, but it’s not thriving. I’m thinking of repotting it in 50-50 kanuma (acidic substrate typically used for azaleas) and pumice next year.

In California, our irrigation water out of the tap was pH 8.0 - 8.5. Rainwater is pH 5.0 - 5.5. You can imagine the pH swings my trees would experience when they would go from eight months of straight irrigation water to the first heavy rainfall in the fall. This is the acidifying fertilizer I used:

Super Iron 9-9-9

Note what they say in the description: This special formula will help counteract alkaline soil and will enable plants to overcome iron-induced chlorosis. No mention of magnesium. And they shouldn't really have said "Iron-Induced Chlorosis". What they should have said was "Chlorosis due to LOW Iron" (but I think people get the point).

 

[TimberLakers]

Lol thanks sorry bout that nobody answered on here for a while and with my luck answered within 24 hours of me posting a new thread.

I was catching up on some old posts I haven't had the time to browse.

Really helpful and interesting color Bonsai Nut. I think I read some of your citrus notes a year or two ago re: acidity when potting mine for first time. Have had good results here with a mix of 40/30/30 (aka/pum/lav) and no discernable difference when swapping out aka for kanuma. Miracid and organic pellet fertilizer.

I've never attempted Citrus in the Northeast- took a liking to them in the Bay. Good luck to you with these through the winter.

 

[LemonBonsai]

Don't worry about it... it just makes things confusing when people are trying to follow one conversation to have it spread over two threads.

Read the article I posted and make sure you understand the concept of pH as it applies to nutrient uptake in plants. Different plants have different needs, and have evolved to flourish in different conditions - however take a look at this graphic for a general indication of what I am talking about.

View attachment 334780

If you have your citrus in acidic soil, and are watering with acidic water, it will not be unusual if you see lighter green or yellow foliage from chlorosis due to MAGNESIUM deficit.

If you live in Orange County, California, named after its citrus fields, you may experience similar-looking chlorosis due to IRON deficit from alkaline soil and alkaline water. That is why citrus growers in SoCal acidify their soil (to lower pH), while citrus growers in Florida add lime to make their soil more alkaline (to raise pH). With citrus you want to be right in the middle... slightly acidic... with a pH of perhaps 6.5 being considered optimal. Remember that pH is a logarithmic scale, and that pH 6.0 is ten times more acidic than 7.0, and pH 5.0 is 100 TIMES more acidic than 7.0. Small numerical changes in pH make a big difference as you move farther away from neutral. This is definitely a case where if "slightly acidic" is good, "very acidic" is NOT good.

I had over a dozen mature citrus trees in California, and spent a lot of time babying their soil pH because of clay alkaline soil and extremely alkaline irrigation water. Here in North Carolina I'm not even sure you can find acidifying fertilizer - but they sell lime by the truckload.

Thanks for the info. That illustration is usefull. Now my question is there must be a cheap soil ph tester kit that I can get? And I am not familiar with ways I can change the ph in my soil. Is there a way I can do this other then completely changing the soil they are planted in?

 

[Bonsai Nut]

Thanks for the info. That illustration is usefull. Now my question is there must be a cheap soil ph tester kit that I can get? And I am not familiar with ways I can change the ph in my soil. Is there a way I can do this other then completely changing the soil they are planted in?

Are you on city water or well water? Here in the states, if you are on city water they have to release water quality reports at least annually that will tell you information about dissolved minerals in your water, pH, etc.

But otherwise pH test strips are cheap. To test your soil, you buy distilled water (pH 7.0). Take a reasonably sized soil sample that is "clean" - ie isn't contaminated with fertilizer or other chemicals. Add the same amount of distilled water. Stir, breaking up large clumps, etc. You want to make thin mud. After you are done stirring let the sample sit for 30 minutes. Strain your mud through a coffee filter. Test the liquid that comes through the filter with a pH strip.

 

[LemonBonsai]

Are you on city water or well water? Here in the states, if you are on city water they have to release water quality reports at least annually that will tell you information about dissolved minerals in your water, pH, etc.

But otherwise pH test strips are cheap. To test your soil, you buy distilled water (pH 7.0). Take a reasonably sized soil sample that is "clean" - ie isn't contaminated with fertilizer or other chemicals. Add the same amount of distilled water. Stir, breaking up large clumps, etc. You want to make thin mud. After you are done stirring let the sample sit for 30 minutes. Strain your mud through a coffee filter. Test the liquid that comes through the filter with a pH strip.

Ok thanks for the tip on the soil test. As for water I only use rain water/snow

 

[LemonBonsai]

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Are you on city water or well water? Here in the states, if you are on city water they have to release water quality reports at least annually that will tell you information about dissolved minerals in your water, pH, etc.

But otherwise pH test strips are cheap. To test your soil, you buy distilled water (pH 7.0). Take a reasonably sized soil sample that is "clean" - ie isn't contaminated with fertilizer or other chemicals. Add the same amount of distilled water. Stir, breaking up large clumps, etc. You want to make thin mud. After you are done stirring let the sample sit for 30 minutes. Strain your mud through a coffee filter. Test the liquid that comes through the filter with a pH strip.

Want to pick your brain on this. So I am using rain water as of now to water my plants and have used it so far. However rain water according to google can range from 5.5 to 4.0 in extreme cases. However I do have Reverse Osmosis water in my house which is a ph of 6.5 now the trade off is nutrients. Rain water is filled with nutrients that RO water does not have. However since I am using superthrive and dynagrow on my plants would this be an acceptable trade off for a better PH value in the water? Atleast for the citrus. How much nutrients would I be losing if I used RO water instead of rain and would it benefit me to go the more alkaline PH water route?

 

[Forsoothe!]

I think there's some scare tactics here in characterizing rain as 4.5 pH. Rarely, and in just a few places downwind of a major polluter. Test yours before you rule out what you have. Your prevailing winds are westerly. Look at the map. There is essentially no heavy industry west, north or east of you.

 

[Bonsai Nut]

Want to pick your brain on this. So I am using rain water as of now to water my plants and have used it so far. However rain water according to google can range from 5.5 to 4.0 in extreme cases. However I do have Reverse Osmosis water in my house which is a ph of 6.5 now the trade off is nutrients. Rain water is filled with nutrients that RO water does not have. However since I am using superthrive and dynagrow on my plants would this be an acceptable trade off for a better PH value in the water? Atleast for the citrus. How much nutrients would I be losing if I used RO water instead of rain and would it benefit me to go the more alkaline PH water route?

Rainwater should have a pH of around 5.5 unless you live in an area with a lot of air pollution. Depending on the type of pollution, only then might you see pH drop as low as 4.0 (so-called "acid rain"). If you lived in an area where this was an issue, I'm pretty sure you'd already be aware of it. So assume your rainwater is pH 5.5 unless you know otherwise. You can always test it with pH strips

Pure rain water is not filled with nutrients. It has no trace minerals at all, and the only macronutrient present will be in the form of nitrogen compounds - which are absorbed as rain passes through the atmosphere (which is 70% nitrogen). So as long as there is nitrogen present in your fertilizer, you will be fine.

What comes out of a reverse osmosis system is greatly dependent upon the quality of the water going in. It is important to understand that reverse osmosis does not discriminate when it comes to dissolved compounds and minerals - it will tend to reject all of them to a greater or lesser extent (typically rejection rates of 85%-95% are common). That may include minerals like iron, magnesium and manganese which might be beneficial to plants, as well as sodium and chloride, which are not.

Ultimately, I think rainwater is great for your plants, as long as you don't also have your plants in an acidic soil mix. I keep coming back to the same thing - test your soil pH. Until you do, you won't know where you stand.

 

[Leo in N E Illinois]

A couple points.

First, if you are getting water from a municipal system, call the police, the EPA, and your local Health Department if the water coming out of your tap is less than pH 7.8 because they are trying to kill you with lead poisoning. Municipal water MUST be buffered to pH 7.8 to 8.5 to prevent lead leaching out of pipes, and brass fixtures into your drinking water. The City of Flint, MI lead poisoning event was caused by the City of Flint switching water supply and not sufficiently buffering the water pH to a level above 7.8. As a result thousands of children of Flint now are dealing with the mental retardation and behavior effects of low level lead poisoning. So if your tap water has a pH below 7.8, don't rejoice for your plants, panic for your children, or grandchildren. If you are on a private well, check the history of your supply lines. Make sure you have no lead pipes, and if you have copper pipes, that the solder used was lead free. Your personal health is more important than your trees.

Second. Relying on pH is a fool's errand without understanding the total alkalinity of your water. Total Alkalinity is a measure of the buffer capacity of your water. Low total alkalinity, a measure of buffer capacity, means pH is very easy for plants to regulate without human assistance. High total alkalinity, means it is difficult for plants to regulate the soil pH, and you will have to use large amounts of chemicals to lower your pH.

Best way to get your water chemistry is to get a copy of the yearly water reports all local municipalities are required to make public. In USA a test lab will do a complete analysis for around $125 or just Total Alkalinity test as a single test runs about $40. 2 most important tests are Total Alkalinity and Total Dissolved Solids, pH is a less important test.

If your Total Alkalinity is less than 125 mg/liter as calcium carbonate, also written as 125 ppm as calcium carbonate, if your Total Alkalinity is below this level, your water is soft to medium on the hardness scale and you have absolutely no need to worry about pH. Your plants will be able to buffer the soil with their own roots and you simply don't have to worry. Unless you are growing real sensitive carnivorous plants. As an approximation total dissolved solids of 150ppm or less will indicate that your total alkalinity will be less than 125 ppm as calcium carbonate. If tests are performed correctly Total Alkalinity will ALWAYS be less than Total Dissolved Solids. TDS is always written as parts per million, the units remain the same when converted to milligrams per liter as long as you are talking about water solutions.

Medium hardness water is total alkalinity of 125 mg/liter to roughly 600 mg/liter, in this range water is considered "acceptable" for landscape nursery use. You can compensate for the higher calcium content of the water by use of acidic fertilizers, and choosing potting media components to help the plants buffer their root zones to the proper growing range. Here using bark, and or peat moss as a component of your potting mix will help reduce the total alkalinity. Top dressing potting mix with elemental sulfur will help reduce alkalinity. Collecting rain water, in areas with regular rain will help. Eastern half of North America, collecting rain is actually quite practical. I collect enough rain with half a dozen open 3 gallon pails, scattered around the back yard, I then empty them after a rain into a 55 gallon open top barrel. I can keep the barrel at least half full for most of the year. I rarely have to use "tap water".

Hard water is above 600 mg/liter as calcium carbonate or over 650 ppm total dissolved solids. Only here do you really need to think about using various methods such as RO or DI water. If your water comes from a well, that is in a limestone aquifer, you might be in this situation.

I wrote quite a bit more, but I am tired of typing. Search posts in threads on pH and look for posts by me.

@LemonBonsai - you are in Ontario, Canada, that is on the Laurentian Shield, your bedrock should be granite. You should have fairly low total dissolved solids for your municipal water. I doubt that you should be needing to worry about your water pH.

 

[LemonBonsai]

Are you on city water or well water? Here in the states, if you are on city water they have to release water quality reports at least annually that will tell you information about dissolved minerals in your water, pH, etc.

But otherwise pH test strips are cheap. To test your soil, you buy distilled water (pH 7.0). Take a reasonably sized soil sample that is "clean" - ie isn't contaminated with fertilizer or other chemicals. Add the same amount of distilled water. Stir, breaking up large clumps, etc. You want to make thin mud. After you are done stirring let the sample sit for 30 minutes. Strain your mud through a coffee filter. Test the liquid that comes through the filter with a pH strip.

So I did the tests. Now im not overly sure at what soil I used on the lemons that have that one seedling with the deficency. However I would imagine I used 45% peat moss, 45% potting soil, and around 10% compost. With these the test resulted in what I believe to be inbetween 5.0 and 5.5

Are you on city water or well water? Here in the states, if you are on city water they have to release water quality reports at least annually that will tell you information about dissolved minerals in your water, pH, etc.

But otherwise pH test strips are cheap. To test your soil, you buy distilled water (pH 7.0). Take a reasonably sized soil sample that is "clean" - ie isn't contaminated with fertilizer or other chemicals. Add the same amount of distilled water. Stir, breaking up large clumps, etc. You want to make thin mud. After you are done stirring let the sample sit for 30 minutes. Strain your mud through a coffee filter. Test the liquid that comes through the filter with a pH strip.

So I did the test on both soils. I cant fully remember what soil I used on that lemon seedling pot but I could imagine it was peat moss, potting soil and a little bit of compost however I may have not used compost. Anyways the test resulted in somewhere between 5.5 and 5.0 the picture makes these look way lighter then they actually are for some reason.


And the 50% perlite 50% oil dri landed right inbetween 6.0 and 6.2


So according to that scale the perlite and oil dri should be a good composition but I dont really want to repot the lemons in the potting soil mixture right now so how can I add something to make the soil more alkaline so that it goes up to the 6.0 range?

 

[Bonsai Nut]

So according to that scale the perlite and oil dri should be a good composition but I dont really want to repot the lemons in the potting soil mixture right now so how can I add something to make the soil more alkaline so that it goes up to the 6.0 range?

Do a search on "garden lime". There are tons of products out there to chose from, but at their heart they are going to be either made from calcium carbonite or dolomite (which is calcium magnesium carbonate). Both products will increase the pH of your soil while increasing its buffering capacity to resist pH swings in the future.

Since you know the volume of your soil and its pH, you will be able to calculate how much garden lime to add to your soil to raise the pH 1 point (based on the instructions on the garden lime product).

 

[LemonBonsai]

Do a search on "garden lime". There are tons of products out there to chose from, but at their heart they are going to be either made from calcium carbonite or dolomite (which is calcium magnesium carbonate). Both products will increase the pH of your soil while increasing its buffering capacity to resist pH swings in the future.

Since you know the volume of your soil and its pH, you will be able to calculate how much garden lime to add to your soil to raise the pH 1 point (based on the instructions on the garden lime product).

Thanks for the info. So I actually just received this as a gift lol and I tried it just to see and according to this both soils are much to alkaline? Are these things accurate? Or does the soil need to be wet while testing it? All in all now im confused because this says 7.0 and above and the other way said to acidic lol

 

[Leo in N E Illinois]

Soil must be wet for pH meter to have something to read. By definition, pH is only meaningful for water solutions. pH meter must have electrodes at least in moist soil, if not wet soil.

 

[LemonBonsai]

Ok so I decided to mix some new soil and try and land on the right ph this time. Which I did and as you can see in this picture one of the pots is exactly at a ph of 6.
The meter was level on level ground. However when I tested the other pot with the same soil i was suprised to get this reading.


Almost at 5! I assume that this is a dangerous level of acidity for the lemons? Or perhaps the meter is off? They have been in this soil now for 2 days. Anyways if it is a dangerous level of acidity can someone let me know what to raise the ph with. If its not dangerous then I will leave them be and see what happens.

Btw this was a very delicate repot and used superthrive and the seedlings havnt shown any signs of stress

On a seperate note would hydroponics "PH UP" and "PH DOWN" help at all with changing soil ph?
Thanks everybody!

 

[LemonBonsai]

Just bumping this to get some direction on where to go with the acidic pot