Best soil mix for blueberry raised bed?

I’m putting in a raised bed for blueberries due to my alkaline soil (7.2 pH) and plan to create a peat based soil mix to provide the plants the proper acidity. Are there any other soil amendments that would be beneficial to blend with the peat to create the ideal soil structure and growing conditions?

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Mine is 1/4 sand and 1/4 orchid bark.


Mine is pure peat with a one inch layer of pine bark on top. I yearly add pine bark to replace what has decomposed. I still have to sprinkle a 1/4 cup of elemental sulphur yearly to overcome the alkaline water.


Peat, sand, compost, decaying wood chips and a nice thick 2-3" layer of pine bark mulch. I also use Espoma soil acidifier in the spring.

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I hate bark on soil mixes or on top. Bark by its nature has stuff to hinder decomposition, which is not good for the decomposers you want working in the soil. I prefer green wood chips which I have to apply twice a year because it breaks down.


I’m surprised you mention alkaline soil…that’s not expected in most places in PA is it?
Anyplace rhododendron, hemlock, mt. laurels are found in nature…that soil taken home and put in a raised bed is probably better than any concoction you’d buy and mix from a garden or ‘box’ store.
Adding some peat and sand and tree-trimming chips is good…mostly chips on top rather than in the mix.


Vacciniums do well with orchid bark in the soil mix.

Yes I was surprised when I got soil test results- high pH, Mg, and Ca, but low in P & K and somewhat low CEC of 11. l’m thinking it is likely due to the fill dirt the builder used in our subdivision. The soil seems more chalky than what I see in the fields nearby. Also there is a small farm just down the road with blueberries that seem fine. Maybe over time our soil will revert back to more acidity, but the neighborhood is almost 20 years old now, so maybe not.

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Thanks Richard. Any recommendations on where to find orchid bark in larger quantities? I see some online vendors, but it looks pricey for small amounts. I’m not sure I’ve seen it in our local garden stores.

Soil pH in residential gardens is usually dictated by the pH of the municipal water supply.

I buy it in 2 cu.ft. bags from the local outlet of the professional supply chain Nutrien Ag. It is available in different diameters, grades, and by the pallet.

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So I’m just going to throw this out there, but pH seems to be an obsession with blueberry growers and it kinda makes me shy away from trying to grow them. I almost hope it’s one of those old wives tales that seem to be ever present in the gardening world. Is there anyone here who successfully grows blueberries without amending for pH?

Well define success. Marginally low acidity makes them unhappy, too low and they die. Long story short in low acidity soils they can’t absorb calcium and magnesium, plus a host of the trace elements.

I would guess anybody with a naturally slightly acidic soil would have good luck without even trying.

Southern highbush and rabbit eye blueberries are less picky about pH, although more picky about lack of winter chill.

Some hybrid blueberries such as Monrovia’s Sunshine Blue perform equally well in trials I’ve had at pH 5, 6.5, and 7.5.

I’m in Vista, southern most coastal CA.

Here’s a chart that shows what’s available,at different pH levels.Iron is another nutrient,that is difficult for Blueberries to process at higher alkalinity.


Also worth noting: not all plants want all minerals. Northern blueberries prefer low pH because (1) they evolved in it, and consequently (2) they function poorly with too much availability of certain minerals.

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It’s really not a wives tale. First discovered and documented by White and Colville in the early 1900’s in New Jersey which provided the foundation for the start of commercial Blueberry production. His publication is still available and contains a lot of interesting photos of of how well Blueberries grow in different soils and with various additions like lime or manure.

Some areas have perfect native blueberry soil which requires no amendments. Pine Barrens area in NJ and Southeast NC are a couple of examples. Rabbiteyes are less sensitive to PH but NHB and SHB refuse to grow in some areas even after PH correction and large amounts of pine bark fines and peat moss. I live in one of those areas.

Some places sell pine bark fines by the pickup load if you have a large area. A mix of pine fines and peat moss combined with native soil works well here, but NHB and SHB refuse to grow well even with the amendments.

Edit Found a free preview of the book with hot links in the index that will take you to a topic of interest

Very important research that helped to create the one billion dollar commercial Blueberry Industry in the US


Ah ok, thanks for the help everyone, maybe I’ll give it a go with a pine bark/peat/compost mix.

Sunshine Blue is a medium producer of a mid season berry at an average to slightly smaller berry size. Blueish leaves that hang on longer in fall than some. 36 to 42 inches tall…sometimes clump-forming from traveling roots. Not too picky about clay soils or almost-neutral pH. Gets frost/freeze damage in some seasons as it breaks dormancy pretty easily.
Not as finicky in zone 6b as some blueberries. It does ok in straight soil that has quite a bit of clay content. (Better on a raised area than a depression though.)

Awesome thanks for the link!

Most likely the PH of your compost will be in the mid to high 6’s which could be a problem for your new Blueberry plants.

I clipped a picture of Elizabeth White and her Blueberries from around 1920.