Decreasing PH of soil for blueberries

I have some questions regarding acidifying soil. Last spring I planted several blueberry plants in a new bed. I added aluminum sulfate beforehand and at least a couple times during the growing season as my soil is alkaline. The plants did not grow much but they did not look unhealthy, either -- the leaves were green -- there just weren't very many leaves. Well I just checked the soil and the PH varies from 6.5 to about 7 in the bed. I am wondering if I should add a bunch of aluminum sulfate or give up on this bed for blueberries. I have read in a couple places that it is more effective to use a raised bed for plants that need an altered PH from what your soil naturally is. Why is that? What is it about a raised bed that would maintain acidity? Why is that different from a bed in the ground? And if I were to do a raised bed, and wanted to buy soil for it, is there particular soil I should get? Is some bagged soil acidic? Or would I be adding alum. sulfate regardless of what soil I use? Or should I just leave the blueberries where they are and try again to amend that soil?

Thank you for any advice!

My soil is naturally acidic but blueberries took some time to get going for me too.
Were they bare rooted? I read they don't like that and take longer to get established. My two bare rooted ones did take ages to grow.
Have you added organic matter and mulch? They are very shallow rooted and really like to stay moist.

dig a big hole 10X the plants roots and put 90% compost into it maybe that would help.

It's not that a raised bed would maintain acidity it's just that unlike soil in the ground it would be easier to change/maintain the ph of soil in an enclosed space. The ph in my woodland garden last tested at about 4.5 so that is blueberry heaven but it doesn't get a lot of sun. I did plant two bushes last spring and like you they are living but not thriving. I think like everything else they are going to take time if nothing else to adapt to the conditions versus the pot they were living in. You may try adding some peat into the soil around them. That would help with the acidity and the drainage if worked into the soil. Good luck and I want a piece of the first blueberry pie!!

Doug

I dug a 3 foot by 3 foot hole and filled it with finely ground pine bark, potting soil and lots of peat. I mixed only about 15 percent local soil into the mix.

Frankly, it is easier to buy a 20 gallon pot.

Bunnerrunner,

I have been told to dig a very large hole, out past the mature dripline of the blueberry bush. Fill it with 50% compost & 50% peat moss. Use drip irrigation to keep this mixture nice and moist. Remember, these are plants with very special growing conditions.

I just noticed your location Bunnerrunner, Saline, MI??? Hmmm, It's note alkaline like Colorado, but I would think your soil would be a little more acidic.

Are blueberries really that much better than raspberries, blackberries, boysenberries, etc.?

I am still contemplating whether I want to hassle with all the special pampering blueberries would take to grow in my area.

Good luck!

Sonny

This message was edited Mar 27, 2011 5:18 PM

Pewjumper--since they need special pampering and prep in YOUR area, maybe not. But around the acid east, they sure are worth sticking in the ground and standing back. ( and beating off the birds)
For my family the lack of seeds, and sweetness, easy care, and no stickers, as compared to raspberries, makes blueberries the preferred.

I agree with sallyg. Our blueberries are doing well in the acidic clay we call "soil" LOL

Pewjumper. do any of those grow naturally, wild, in your area?

Try adding some soil sulfur instead of aluminum sulfate.
Mulch with pine needles to add additional acidity.

Sallyg,

Wild blueberries in Colorado? Not a chance. The pH of the soil is much to high throughout the vast majority of the state except for a few small peat areas. The key to acidic soils is largely reliant on the amount of annual rainfall you have.

I have a 2000 sq ft area that I will start work on this year. Rocks, clay & a pH of 8.17. I threw down a 50 lb. bag of soil sulfer about 18 months ago in the hopes it would knock down the free alkalinity before I really start the hard soil prep work.

Soil and fertilizers for azaelas & camelias/acid loving plants is usually a pretty good place to start, but remember that blueberries like a soil that retains moisture but drains well.

Sonny

I have found that many landscaping mixes are fine ground pine bark mixes. You cant always visually tell how much pine is actually in the mix so I always tear the bag a little bit and smell the mix. If you get a really strong pine smell from the bag, you have hit the jackpot. The pine will usually be in little 1/4 - 1/2 inch bits. They mix into the soil very easily and decompose over a long period of time. Mixed with peat and regular soil, it makes a good mix.

Its tougher to fight the plants preferences. I didn't know of any 'cane' berries take that well, or if they also like a more acid soil. Its such a curse living in the Eastern woodland...not!

With luck you can find very find pine mulch itself at a mulch price.

My local garden center manager advised transplanting my blueberry bushes into containers--I only have two, so it wasn't a big deal. He said that our soil is so alkaline I would never be able to keep the soil acidic enough for blueberries to thrive. So I purchased a couple of large plastic planters. This spring I added 2 cups of sulfur to each. The plants survived the winter without extra protection and are budding out already.

Hmmmmm,

Very interesting Goldenberry. I have a bunch of 1/2 wine barrels that I was thinking of using for blueberries, but I was told that they would freeze solid and the plants would die or worse! LOL

Keep us posted on your potted blueberries. Which varieties are they?

Sonny

Pewjumper,
Where do you find soil sulfur or ammonia sulfate in CO. I have looked all over for soil sulfur and ammonia sulfate w/ no luck. Most people at the store look at me like I am crazy. I have even tried the garden centers and they either don't know or have never heard of it. I have been adding coffee grounds and peat moss to the beds that are really bad, but it hasn't helped enough.

Onyxwar,

I went to our local co-op, (Agricultural supplier) and they special ordered it for me. If you don't have a farm supply in your area, go to Ace or True Value hardware and have them pull out "The Big Book" which has just about anything you can think of. Most stores don't like to use the Big Book because it's a hassle and the clerks are lazy.

If you are trying to change pH in your soil, you really have to create new soil. Trying to grow blueberries in most areas of Colorado is impossible due to our soils high pH and high alkalinity. The buffering capacity of the calcium carbonate alkalinity, (CaCO3) must be eliminated before any change in pH can occur. Even then the calcium carbonate in our water will over time raise the pH. Most of our alkalinity in the Glenwood Springs area is derived from limestone.

Sonny

This message was edited Apr 5, 2011 6:02 AM

Pewjumper, I would have to dig through my big box of plant labels to tell you what kinds they are. I do have two different ones for cross-pollinating purposes. One is Northern- something. I'll look for the labels tonight. I need to get them all better organized anyway. One of those winter projects I didn't get around to, sigh.

As for the freezing, I see we live in the same zone! The nursery manager did tell me I might have to move the pots to a sheltered area for the winter. My blueberry bushes live just outside the drip line of some massive Colorado spruce trees in my front yard, facing southeast. There are hollies and a fence nearby so they get winter protection from the north winds. I did not move or wrap the planters for the winter and they survived. The beauty of keeping them in pots is that you can move them if necessary.

Onyxwar, look for either Espoma Garden Acidifier, or Hi-Yield Soil Sulfur which comes in a yellow bag.

BTW, Glenwood Springs is a lovely area!

Bueberries are big in Maine so there must be some pretty cold hardy ones. My sister in Florida though, has the big tall rabbiteye kind.

Thanks, I will check w/ the ag stores in the area.

Goldenberry,

We are indeed in the same zone. But the huge difference is that the Rockies shelter us from the massive swings in temperature. Denver is always very different from Glenwood Springs. Glenwood usually just plods along with slow temperature changes through the seasons. We don't have the crazy changes associated with gulf air & Canadian cold.

This last Sunday I saw one of the worst changes since I moved here 12 years ago. It was 62 F when I got up at 5:00 AM, (Extremely strange!) It was 32 F when I left the community garden meeting after church at 12:30 PM. Bizarre weather for us.

I assume you are growing half high hybrids?

Sonny

Better? Maybe not. But here in NC Florida, my rabbiteye and highbush blueberries will be ready to start picking within the next few weeks. We're still months away from blackberries.

BTW, a friend of mine who is a small fruits specialist for the Georgia Extension Service assures me that it is possible to use very dilute sulfuric acid to quickly lower pH. I emphasize VERY dilute - but the effect is virtually immediate. Combined with *dusting* sulfur gives a longer lasting effect (the very fine powder penetrates soils pretty well and is much faster acting than the granular material often sold as "soil" sulfur.

-Rich

BTW, a friend of mine who is a small fruits specialist for the Georgia Extension Service assures me that it is possible to use very dilute sulfuric acid to quickly lower pH. I emphasize VERY dilute - but the effect is virtually immediate. Combined with *dusting* sulfur gives a longer lasting effect (the very fine powder penetrates soils pretty well and is much faster acting than the granular material often sold as "soil" sulfur.

BE VERY CAREFUL WHEN HANDLING ANY ACID!!!

ALWAYS, ALWAYS ADD YOUR ACID TO THE DILUTION WATER!!! I REPEAT POUR THE ACID INTO THE WATER.

NEVER, NEVER PLACE ACID IN A HOSE END SPRAYER!!!

I could be wrong, but doesn't adding acid to calcium carbonate create acetylene gas? I need a chemist to comment.

Sonny

Sonny, to answer your question about half high hybrids, I can only tell you that the label on my "North Blue" plant says it will reach a maximum size of 3 feet in both height and spread. Both of my plants are pretty small. I have had them each for three years. That is my way of saying "what's a half high hybrid" LOL!

Goldenberry,

North Blue is what they call a half high.

What do you think of the berries?

Sonny

To tell you the truth, the birds, chipmunks and whatnot have gotten the majority of whatever fruit is produced; which hasn't been much so far. But I keep hoping! And the few berries I have picked tasted very good.

No, that would be carbon dioxide. You may be thinking of calcium carbide, but it just needs water to evolve acetylene, not acid.

Thanks rjogden!

I have worked with various acids over my lifetime & I always treat all of them with great caution.

Sonny