A Question About pH,Peat and Lime

I am currently growing some Stone fruit trees in containers.The planting mix is mostly Conifer bark mulch and Peat moss.Those two are fairly acidic,especially the Peat.,at about 5pH from what I’ve read.
According to different sources,Stone fruit grow best at about 6.5 pH.
My question is,does anyone have experience or info about the ratio of Lime needed to raise a Peat based mixture,say a gallon,to the desired level?
Right now,I throw in a handful or two to 15-25 gallons of mix.
Maybe I’ll do some testing with different amounts,like 10/1,20/1 etc. Brady

All limes are not equal, so it depends. I know in the houzz forums on container growing, Al mentions what he used for the 5-1-1 mixes. He says 4 tbsp of garden lime, which i take means dolimite.
The last couple of years I stopped using peat and replaced it with Pro-mx which is buffered already, mostly peat. So no longer add lime. I keep a small amount on hand anyway. I also still use peat for blueberries and cacti.

Here is what Al uses for 5-1-1
Big batch:

2-3 cu ft pine bark fines

5 gallons peat

5 gallons perlite

2 cups dolomitic (garden) lime (or gypsum in some cases)

2 cups CRF (if preferred)

Small batch:

3 gallons pine bark

1/2 gallon peat

1/2 gallon perlite

4 tbsp lime (or gypsum in some cases)

1/4 cup CRF (if preferred)

I also use CRF, but stopped mixing in the mixes. I don’t need fertilizer at the bottom of a 30 gallon pot where the plant takes a season or two to have that many roots. It only promoted algae growth on fabric bags.
I now put it on top of each plant as I plant them out. I find I use a lot less!

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Thanks Drew,I know that guy doesn’t grow fruit,but those mixes should be fine for what I’m doing.
I’m going to try soluble Miracle-Gro this year and see what happens.Last year,CRF was added when the mix was made and they did okay,but want to experiment. Brady

Yeah it should give a general idea. I like to use organic fertilizer to supplement the CRF. Also I found dynamite brand to be the best CRF I have found (9 month release period). The reason I don’t use say miracle grow is I don’t have time to mix it all up. Last year I had about 75 containers. A friend counted them, i never have!

I have a 55 gallon plastic barrel and did some figuring,that 3 cups of MG added to that equals about 1 tablespoon per gallon.I’ll put the fertilizer in first and then the water to mix really well.The thing is on a small cart and raised up a bit,so a 5 gallon bucket can be filled from a spigot at the bottom. Brady

I once sent the pH of some blueberries from 5 to 7 (unintentionally) in only two months after watering them with water from the tap. Most people, if they have public water, their water is a little basic.

Just throwing that out there…changing your soil pH might be simpler than you think!

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Yes,the water where I live is about 7.2 pH.
Were your Blueberry plants in containers with a Pine bark/Peat moss mixture? Brady

No, my blueberries were in a 4x8 ft square raised bed filled with peat moss, compost, and some sand, so not your exact situation.

Later found out the pH of our water was 7.7 and it had a high percentage of carbonates, I believe.

Had to do some sprayings of chelated iron while using sulfur and sulfuric acid in the water to bring the pH back down.

What is CRF? I checked all the posts and did not see a definition. Thanks.

Controlled Release Fertilizer.Osmocote comes to mind.Brady

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I start a lot of trees from seed, one of them is chestnut which likes acidic soil. I typically use Promix combined with additional pine bark. When I first started I was using city water. I ended up with some Iron chlorosis issues. It was not the lack of iron, but the chestnuts inability to take it up given the pH. Promix is adjusted to neutral and my city water probably made it worse.

Since then I’ve established a rain water collection system. The use of rain water, even with a mix that is pH adjusted to neutral will become acidic enough for acid loving trees. I have not seen the issue since using rain water.

As for fertilizer, I like either Osmocote Plus or Osmocote along with micromax for young seedlings.

Rainwater is the best.I’d really like to go that way,especially with Blueberry plants,but during most of the growing season in the Seattle area,precipitation is fairly low. Brady