I would agree that pine needles will do little. They make a great mulch though! I use them to mulch even alkaline plants, like lilacs.

If you want acidic soil add sulfur and wait 6 month, in the meantime use acid in the water. Citric, vinegar, or sulfuric. You can fertilize with cottonseed meal and that is acidic or use ammonium sulfate and that too will turn soil acidic. be careful with that stuff! Holly-tone has some sulfur too.

I've got a pile of blueberry plants that i have a hunch may hit dry spells in their current location. I added tons of peatmoss. The area only goes down about a foot before hitting solid rock. I found some invasive bamboo on the edge, and I think it's drying the soil out too. I'll probably only use the area this year until I can set up their destination better. Rather than the work of collecting pine needles, perhaps I could just lay down some cardboard?

I may give the sulfur a try at their destination I setting up. It's an awesome location, but no easy access to irrigation water, so not sure how much of a problem that'll be here in Okayama.

I saw a report from a professor of horticulture showing the pine straw does not lower the PH of soil but does make a good mulch.

The peat is extremely acidic and that alone should carry the plant for a year.

It is true that acidic soils are consistently found where evergreen forests are located, but it takes something like 1000 years for these soils to form. So, pine needles can be used as mulch around blueberry shrubs, and they will help retain moisture around the roots, but the effect on soil pH will be small, unless you keep adding pine needles, every year, for 1000 years. Blueberries will not thrive if they have to compete with bamboo or any other nearby plant for moisture.

Peat or pine needles make good mulch and help conserve moisture. They will do bupkis to acidify soil. Your choice is, Miracid, or sulpher.

Thanks folks

I tore the area up with a rotortiller down to rock and mixed in a bale of peatmoss last month before planting. There's nothing on top though to preserve moisture, so I'm thinking a bunch of cardboard seeing as it's temporary and easy.

The second area I have in the mountains has a few pine trees, so I covered the ground around the few BBs i planted there as a test this year with brown needles, then whole green branches on top of that.

I want to figure out a cheap irrigation system as a backup in case rain doesn't hack it. Maybe a big tarp in a wooden box frame to collect rain water? Swimming pool?? I made a nice gravity fed system at our smaller plot from an unused bathtub and garden hose attachments. I can fill it with canal water across the street via a pump I made from a washing machine pump running off 2 impact driver nicd packs. A real Macgyver build. The mountain location will be much larger and I don't know if a bathtub will hack it. Also, probably only rain water filling is practice there. Still, better than nothing.

Card board will work for a year or two, I used it on 20 plants to keep down weeds.

Peatmoss & pine straw are low pH, the problem is that when they break down or compost they are a 7 or so pH so they will NOT lower your soil pH.

I just put out 75 bare root blueberry plants with compost & watered them in, then mulched with pine straw. First the straw is free from my 10 acres of pine timber, 2nd it is a great mulch for dry Summers & weed control. I am going to put down cardboard to kill the annuals & control the perennial weeds, until I can hoe them. Plants are on a 10 feet centers, so lot of weeds to manage.

I am organic so no spray for the weeds.

Acidic soils are often found where coniferous forests are present, but that is because the trees prefer growing in such soils, not because they or their debris contributes measurably to lowering the soil pH. As noted above, when plant debris decomposes, it approaches a neutral pH of 7.0.

Soil acidity is primarily the result of the underlying mineral content of the soil. Areas that have natural rock formations or bedrock that is more acidic in chemical composition - like granite and basalt - will have acidic soils. Those with rocks that present more alkaline chemical properties - like limestone and shale - will have more neutral to alkaline soils. The biggest secondary factor is the amount of rainfall - areas with heavier annual rainfalls tend towards acidic soils; arid areas have soils more towards the alkaline end of the scale.

Muscadines,

" there are so many uneducated fools out there ". I don't think such a strong statement should be made. We were all "uneducated fools" at one point, weren't we?

thiniceguy,

You can collect rain water with a trap, like a funnel, if you know you will have a dry Summer.

Pvc pipe is cheap, anyone can learn to glue it up & a rain bird sprinkle head will work with water hose.

Here is a link that may be helpful:

http://www.sprinklerwarehouse.com/PVC-Pipe-s/7733.htm

http://www.rainbird.com/landscape/resources/FrictionLossCharts.htm