So I have picked up the Potash, Gypsum(calcium), Manganese and Borax. I am not sure how much exactly to apply.
Here is what I am planning to do, does it sound ok?
Do I need to apply more or less of anything?
I am done with the 12" flooding of backyard. Moving on to the front yard next.
Thanks!
@Steve333
@Hillbillyhort
@Richard
@fruitnut
I went ahead and spread about 1 pound of borax and 1 pound of Manganese over 3000 sq.ft. of lawn/fruit trees/roses. I hope I got the math right.
With the potash and gypsum I think I need to be adding a lot more than just 1 pound / 50 pounds⌠I think 5 more pounds of potash and 50 more pounds of gypsum?
Does anyone know for sure? I am afraid I might over apply⌠The calculations on how much to add seem so confusing. With my current levels how much potash, gypsum should I add?
Appreciate any thoughts on this, Thank you!
Adding gypsum to west coast soils is a poor idea.
Further, your soil currently has a high phosphate content and adding more components to the soil at this point isnât going to help.
You should focus solely on foliar feeding until the P abates.
The idea of âbringing soil nutrients up to levelâ is antiquated. It is also not applicable to soils that are neutral to alkaline in pH. You are using municipal water for irrigation that is neutral to slightly alkaline by design. This is to prevent city pipes from corroding. You should definitely mulch your plants to prevent the soil from drying out. Mixing prilled sulfur into the mulch will help lower the soil pH. Until that happens your soil chemistry is not going to change.
Richard ,why is gypsum bad for a west coast soil ?
I would think it will raise her ca. But not raise the ph.
Just want your thoughts
If you are in a place with monthly (or weekly) rainfall, then there is a chance that adding gypsum will help leach out unwanted minerals. But itâs not going to happen here â even with regular irrigation because soils beyond the plant holes are water-immobile.
There is Calcium in our soils and in our water. Raising the Ca level in her soil will complicate her problems with alkalinity.
The concept of âraisingâ soil levels of nutrients is antiquated. We take soil tests to determine what not to add, period. When you do add something itâs calculated on a per-plant basis â not a soil density basis. The latter will result in the majority of your application heading downstream and fouling waterways and/or the ocean.
Iâm not familiar with W CA soils, but in the Rockies especially on the front range, gypsum is used extensively to add Ca to alkaline clay soils without raising the pH. In fact, you have to special order plain ground limestone in as most garden centers and Ag stores here donât even stock it. And I suspect we are in an equally moisture challenged area.
It generally comes down to whether the soil is a clay based one, with high levels of Mg (relative to Ca) or not. As I mentioned above, Iâm guessing that @Girly has such a clay based soil, from the high CEC number and high Mg readings. But maybe not. I have been to SJ many times but not gardened or dug in the soil there. If this is a clay-y soil, gypsum does help both in loosening the clayâs effects and in bringing the Ca-Mg ratio more in balance. Making that addition can be done largely independently of other stuff you may (or may not) want to adjust.
But back to Girlyâs most recent question, the amounts you had in mind: The 1# of Borax and MnSO4 per 3000 sqft, seems in the ballpark. Perhaps even a bit low for the Mn given the ppm numbers you are starting with, but best to start slowly with these elements which can be toxic. I donât know that lawn and other plants specifically need those elements (and a few crops like strawberries are quite sensitive to too much B). But those levels seem OK, although they seem quite a bit more than the 1T per tree we originally spoke about. I would definitely NOT add more until you had another test in a years time or so, and see what the levels are then.
You might want to go back to the testing lab and ask them. I have not seen this format of lab results before, and there are a couple of things which are unclear (to me at least). For example, the top chart has B at 0.3ppm and the lower one, I just noticed, had it at 0.8ppm. Which is it? (either way, you were on the low end so no worries, but it would be nice to know which it is). Most labs will give recommendations based upon their tests. Perhaps that is what their bottom most box is for, but it wasnât clear (again to me at least) whether they just forgot to fill that in, or intentionally were saying donât add anything. Might be worth asking them.
I suspect putting more K down (pot sulfate) is optional, at least as far as the fruit trees go. They arenât fruiting yet when their K needs go up, and you have decent levels already. And as Richard mentioned, unused ferts can end up downstream if they are not used up by the plants. So if you do use it, perhaps spot treating the trees or other plants rather than a general broadcast? But itâs up to you.
The gypsum too is optional, depending on what you are trying to do with your soil. Your Ca levels are currently med-high, so likely enough there for now. If your soil is very clay-like and youâd like to mitigate that, or if youâre following Albrechtâs âformulaâ for soils, then it would make sense to add some gypsum to those ends. Again it is up to you, and what you are trying to do with your soil. Adding gypsum will not increase (or lower) the soil pH. The amounts of gypsum will depend on what you are trying to accomplish with it.
There are many categories of clays.
You are in zone 5a. Your annual evapotranspiration isnât close.
A serious issue is that she took all the advice as being valid and is doing every one. This is a recipe for failure.
It will cause the formation of calcium phosphate which will exacerbate her soil conditions for years.
If anyone in this thread has further questions for me please send a PM.
Thank you all for your inputs!
Yes, my soil is severe clay based.
It used to be very alkaline as well. So I added sulfur in summer 2017. The Ph now is now 6.8
Yes, I added 1T per tree and there was some left. So I figured why not use it on the lawn instead of throwing it out⌠If the lawn dies, Iâll be the only one to blame 
The testing was done by A&L Labs, Modesto CA. I have called them multiple times over the last 3 weeks and left messages. They say they will call back but donât. I did pay for the tests to include recommendations as well.
I did some reading on how excess of phosphorous prevents absorption of other nutrients and what your saying makes a lot of sense now! Thanks!
Iâll foliar apply the Alaska to the Washington Naval Orange alone and keep you posted on how it does.
@Richard
What type mulch should I use? This is what I have been using so far - https://www.homedepot.com/p/Kellogg-Garden-Organics-2-cu-ft-Gromulch-2-in-1-Planting-Mix-and-Mulch-621/100427388
It is fine wood chips/dust⌠Continue to use this or look for the big sized redwood chips or something else?
I prefer to avoid the non organic ones colored with chemicals