Home remedy for alkaline soil - containers

[StevePots]

So I got my test meter. It tests for moisture and Ph. Tested it with vinegar and it does read correctly.
I recently changed my container's soil. I just had too many problems with it holding too much water.
Testing the new soil I find it to be over 7 close to 8. All the plants I am trying to grow apparently prefer 6.something to 7 Ph.

I see soil acidifiers on the shelves but I was wondering if there was something else I could use. Somebody suggested wood ash or even charcoal.
Maybe I don't even need to fix this.
Any thoughts.

[Taiji]

Out west we use powdered gypsum to lower ph. It's really cheap at Home Depot. I believe wood ash raises ph; that's a no no out here.

[imafan26]

If your soil in containers is mostly compost that is your problem. Compost will test close to 8 and hold too much water.
Using potting soil in the pots not compost and it will work better. If your soil is alkaline you do not add wood ashes or lime as it makes it even more alkaline. Sulphur or peat moss would be used to lower pH. Sulphur takes about 6 months to correct. Gypsum is also calcium (alkaline) but it does not change pH that readily, it is used mostly for saline sodic soils and to make hard clay soils more workable.

Cabbages, and baby's breath could grow in more alkaline pH.

[Taiji]

Didn't mean to misinform about gypsum. Out west we've always thought it lowers ph, but after reading what imafan wrote, as well as googling it, it seems that this is a myth! Since my soil is in no way heavy clay, I guess I'll stop using it!

[rainbowgardener]

Yes, wood ash is a strong ALKALI, exactly the wrong thing to use if you want acidification.

Agree with what imafan said - sounds like your mix is all wrong for containers -- not only pH too high, but too heavy and moisture holding. You probably want to dump all that in a wheel barrow and mix it with equal parts of peat moss/ coconut coir, and some kind of mineral element -- perlite, crushed rock (lava rock, pumice, granite, etc).

[Susan W]

Steve, let's go back to square one. How many containers, how big and what did you use to fill them? Warm to hot temps and plenty of rainfall a given for you, though you may need to water some if no rain for a week.

I have 100+ containers, 10" on up to 18". Herbs, a few veggies, annual and perennial flowers and more. I am working on a living soil balance for them which works best on the larger containers. I don't have the months of warm to hot as you, but plenty of rain (about 35" so far and usually up to 50+ inches/yr).

[StevePots]

Steve, let's go back to square one. How many containers, how big and what did you use to fill them? Warm to hot temps and plenty of rainfall a given for you, though you may need to water some if no rain for a week.

My containers range from 5 Gal buckets up to 15 gallon "pots" (the type nurseries have trees in). I used store bought organic compost, potting soil and topsoil. All in bags. I use a good amount of perlite in each container.

I just added 2 new 15 gal containers. In those I used 1/2 potting soil, 1/2 mushroom compost (it was on sale) vermiculite, perlite and 4 pounds of worm castings. The two new containers have Oak Leaf Lettuce and Little Wonder garden peas in them and the seeds just sprouted and are looking great.

All together I have about 18 pots and containers.

I was worried about the mushroom compost because some say seads don't like to sprout in it.

I have declared war on water retention. I will never (thats a long time I know) use peat moss again.
It rains so much here everytime a tropical storm passes that the containers fill up with water to the point where the plants get washed right out their soil.

I like my new mushroom compost mix with vermiculite and perlite. The water does not dam up but the soil stays moist for a long time after rain.

Anyway my soil in all containers (did not check the two new ones) tests between 7 and 8 pH I need 6 to 7 pH.

So I bought soil acidifier (an organic brand) It is interestingly enough made from elemental sulfur and gypsum. I just measured it out according to directions and now I wait 60 days to see if I managed to drop my pH by one point or not.

Interesting thing also... Found one guy who recommends adding in a few matches when transplanting tomatoes. Just thought I'd toss that out there.

[imafan26]

Mushroom compost is alkaline and if you used a potting soil that said it was pH ballanced= they added lime.

Sulfur takes about 6 months to change the pH. Usually you would not try to change pH more than one point at a time. The reason it takes so long is because it is the soil organisms that must convert the elemental sulfur to sulfuric acid. How fast that happens depends on the type of soil you have and the kinds of organisms in your soil. Usually most people do not try to change pH in a pot, it is hard to control. Most of the time it is easier to start with new soil.
https://blueberries.msu.edu/uploads/file ... Sulfur.pdf

I have not had luck with compost in pots. It holds too much water and the alkalinity causes them to grow poorly and most of the time not at all.

I usually use 50/50 peat moss and perlite plus slow release osmocote. I do add a handful of vermicast to a 5 gallon bucket of potting mix when I have it and it doesn't cause the same problems that compost does.

Peat moss is acidic, but most plants prefer a slightly acidic soil and more plants are tolerant of acidic contitions than alkaline. I can get most plants to grow at a pH of 6.5, except for the alkaling loving baby's breath. Cabbbage grow fine, they mineralize calcium from the soil, so they alkalinize the soil they grow in. I usually have to adjust pH after a couple of years where the cabbage family has been growing. Most of the time I keep my soil on the acidic soil by using sulfate of ammonia for the nitrogen side dressings. My garden has a pH of 6.4. I actually add compost to keep it from going lower.

[StevePots]

Okay so applying common sense, what I learned here and my online research... compost and potting soil are not good in containers. Mostly because potting soil contains a lot of compost and is almost always balanced or neutral.
In fact, going with a good mixture of peat, vermiculite and perlite seems the way to go. That way you get the pH you want and the drainage too.
Plants will have to put on a feeding schedule because the mix has no nutritional value.

Anyway... we live and learn. I'm going to have to soldier fourth with what I have for now. My thinking is that small containers can't be too hard to fix because they are isolated from the rest of the garden.
My lemon cucumbers look happy, my pepper plants are just now getting to bloom again after the Thrips onslaught, and the rest of the garden is loving the cooler days of September. Overall I'm happy with what I have growing on.

Interesting info I'll share: Pine bark mulch adds acids to soil as it breaks down. Pine bark compost might be a good renewable alternative to peat. My logic being that they are both acidic.

Also interesting... I use to note the passing of time and bemoan it. Now I can't wait for time to pass. I'm already planning my 2016 Spring garden.

[Susan W]

Steve, Thanks for breaking that down! Pots are good size, and make manageable mini-gardens.

I use lots of bagged stuff, live in town. I also am picky on which bag! I go for the cheap ($1.50) top soil, and it varies by location. The one I get has dirt, finely shredded wood and sand. It comes out of Muscle Shoals AL, a center for pulp wood, so this may be part of the byproduct of the wood industry. Sometimes the stuff smells green, as the wood has been aged long enough. There's another version called potting soil, same mix sorta, costs a bit more. Sometimes get it depending on that smell. Some cheaper top soils are clay and little else. I've had a few bags that I add a bit and work in just to use it up.
About 1/2 of the mix is the top, or other. Then just throw in (about 1/4) bagged compost which may be cotton burr (not cotton seed), or the Natures Helper from HDep. Your mushroom would act about the same. Then about 1/4 Black Kow bagged poo (I get it at Lowes). This is poo with sand.
All that in the pots. I often fill the lower 1/3 with just the cheaper stuff. Remember, it has sand and will stay draining! After near filled throw in some compost aka enriched dirt from my pile, includes worms, so mix in gently. I have been using some bagged stuff that is amazing, and local. Check your garden centers for local suppliers. This one, Happy Dayz, or something, is worm poo, aged horse poo and leaf mold. It is a bit heavy and rich, but awesome, and is so fresh there are worms! I do know the fellow who puts the product together, and he said he grows directly in it. Talk about plants on steroids!

The whole mix should be able to flow not clump in your hand. No perlite or vermiculite. It's sand that is already in the mixes.

Extra fertilizer optional depending on what you are growing. I used plant-tone and lime in the tomato starts, sometimes put in some osmacote, especially for flowers,and for most herbs is fine as is.

Hope this helps