plantkiller
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Need to add something to acidify soil if using a pot?

Going to put my last few seedlings in a pot, the soil is a mixture of (mostly) Miracle Gro Organic potting soil, some vermiculite and perlite to thin it out. Considering most soils prefer a slightly acidic soil, do you recommend I add anything to it?

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rainbowgardener
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plantkiller wrote:Going to put my last few seedlings in a pot ... Considering most soils prefer a slightly acidic soil, do you recommend I add anything to it?
Did I miss where you told us what kind of plants these are?

It makes a big difference, each plant has its own preferential range of soil pH, which can be anywhere from mildly alkaline to quite acidic.

"most soils prefer a slightly acidic soil" did you mean most plants?

plantkiller
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rainbowgardener wrote:
plantkiller wrote:Going to put my last few seedlings in a pot ... Considering most soils prefer a slightly acidic soil, do you recommend I add anything to it?
Did I miss where you told us what kind of plants these are?

It makes a big difference, each plant has its own preferential range of soil pH, which can be anywhere from mildly alkaline to quite acidic.

"most soils prefer a slightly acidic soil" did you mean most plants?
Hehe yes, I meant to say plants, and we are in the tomato forum :) Several different kinds of tomato seedlings that I have plans to go into grow buckets. Have since read a couple of things that would indicate you should, also some that you don't need to..no specifics on either front. Any advice/tips are most appreciated. Thanks!

TZ -OH6
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Commercial potting mixes are pH balanced for optimal nutrient availability. But over time (a season or two) decomposition/some fertilizer components creates acids which lower the pH significantly and so tomato growers using self watering containers (where the constantly moist conditions speed decay of the mix) will often add dolomitic lime to buffer the pH against these acids. I wouldn't worry about it until you start to have problems. You may never need to do anything.

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applestar
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I think for tomatoes, I would add some kind of calcium source -- ground eggshells or oystershells, lime or dolomitic lime (cal and mag -- some people grind up their Cal-Mag supplement), and a *small* amount of Epsom Salt (sulfur and mag) -- depends on container size but 1 tsp to 1 Tbs (some say 2 Tbs but that seems a lot of salt). I usually add Green Sand for extra minerals. Kelp meal is also good for that.

Keep in mind though, that I'm mixing my own soil mix from somewhat acidic start. Maybe you can hold off on the calcium -- since most ingredients will raise pH -- until flowering since, like TZ said, you're starting from a pH balanced mix. I always thought of tomatoes as liking neutral toward limey soil though.



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