I would mix the Peat with soil and plenty of compost. Peat moss doesn't have the nutrients (if any at all) the plants will need. Good compost will feed them for years.

"Does this sound like a reasonable way to get some bushes to thrive long term?"

Nope, sorry :-( If working with very alkaline soil (and what is the current pH?), it is very difficult to get blueberries to succeed long term. Any amending to lower soil pH should be done well in advance of planting - like last fall - and will be temporary at best. Most soils are buffered to resist permanent changes in pH and will return to their natural/native pH after a relatively short period of time. So you will need to be amending to increase acidity endlessly - hard to do successfully with established plants.

Also, there is a limit to how much you can actually lower pH. If a neutral pH of 7.0 or below, you may have some luck but if much above that, you will likely not be able to lower it sufficiently to make the blueberries happy. Generally a full point is doable (like from 6.0 to 5.0) but not two points - the pH scale is logarithmic and each jump from point to point is a factor of 10. Decreasing from 6.0 to 5.0 is making the soil 10 times more acidic. From 7.0 to 5.0 is 100 times more acidic. from 8.0 (alkaline) to 5.0 (adequately acidic) is a 1000-fold increase!!

The recommendation when attempting to grow a strongly acid loving plant like a blueberry in an area with alkaline soil conditions is to grow it in a container or raised bed, where you can import and tailor the soil specifically to the plant's needs. Even planting in pure peat moss - which I wouldn't recommend - or peat moss mixed with compost - which I also wouldn't recommend - or both mixed with native soil (better) will not maintain necessary pH levels for very long.

I have heard that mixing in a large quantity of pine needles will help with this issue. Thoughts?

They will die in pure peatmoss, and the pH will rise quickly as water carries ions into the pit,

If you truly have extremely alkaline soil (which sounds odd for Ontario) use a large raised container with good potting soil and use fertilizer meant for plants that like acid conditions.

What is the pH and how did you test it?

Pine needles? They are just compost.

Pine needles are not acidic. Another persistent garden myth :-)

Ok so back to the drawing board for ideas.

I tested the soil with a lee valley testing kit. http://www.leevalley.com/en/garden/page.aspx?p=65366&cat=2,42578,65366 Ph test came back in the greenest of green on their scale. Waterloo Ontario.

So if i want to do this right, what is the way to go?

- Build a raised bed? How high? are the suggested width/length still good? Do i just build it open bottom on bare soil? If i'm trying to have totally different soil than my native is there any actual benefit of raised bed vs a container?

- Fill it with what? for veggie gardening raised beds i've just used the cubic yard of soil in the past from local soil places. Amended with compost every year. Can i get acidic soil or do i just have to do soil/peatmoss/compost (what proportions) into this bed and ammend it with something (what?) all this year and plant bushes next spring?

If someone has a step by step recipe i'm willing to follow it.

Few U.K. Gardeners have acid soil. Blueberries are widely grown in containers here. We can buy ericaceous potting mixes for rhododendrons, camellias etc. And it works fine for blueberries. Can you get that in the US?

I think your original plan might work! Last spring I dug out a 2' deep by 4'x 8' wide bed and filled it with a blueberry soil recipe I got online a while ago.

50% sphagnum peat moss
10% sand
10% Your garden's soil /CLAY
10% potting mix
20% perlite

I then built a raised bed on top of that (without a bottom) so there was 6" more soil above ground. I mulched the top 4" with shredded pine bark chips.

My bushes put on more growth last summer than they had in the past 3 years in containers! I check the soil PH every 6 months or so and add either iron sulfate to lower the Ph or just ammonium sulfate to fertilize. It does take more work to grow berries in ground than in containers in most areas. So that's worth noting.

Good advice from gardengal. The home test kits are quite famous for misleading information so no major work should be done based on one.

There are a large number of soil mix for blueberries discussions the search pulls up from over on the Fruits & Orchards forum here you might want to browse through.

http://www.gardenweb.com/gardenweb/query/blueberries-soil/topic=fruit

Dave

Test your irrigation water as well. Trying to acidify an alkaline mix while watering with alkaline water is a losing battle. If your soil is alkaline, and your irrigation water is groundwater, you're sunk.

DITD is correct. You have to acidify the water. Buy battery acid and wear goggles and gloves when mixing (hopefully you have no children at home, the stuff is dangerous). Look at old posts in the Fruit section on Gardenweb for dosage. Also, I agree with GG, if you used tap water results are incorrect. My tap water for example has a pH of 9.2.

A good test would be to pick up a chunk of soil, dry it, pulverize it, and place it in a bowl. Submerge with white vinegar. If it makes bubbles, even small ones, you will never be able to change that pH and will never be able to grow blueberries.

If it does not bubble, and a better pH test comes back close to neutral, you can survive with tons of organic matter, acid irrigation, and a raised bed. Blueberries do not love acidity per se. They like the nutrient availability under acidic conditions, but the same nutrients can be made available under very high organic matter conditions, and moderate pH. Do not forget the mycorrhizae for ericaceae, blueberries do not know what to do with the myc. you have in your lawn.

Finally, I have alkaline soil (pH=7.7), and I love blueberries but hate all that extra maintenance. So I planted haskap instead.

You can also acidify your irrigation water with vinegar. It is a standard practice when watering acid loving plants in places like SoCal that have an alkaline water supply.

Far safer than using battery acid!!

If you confirm that you indeed have very alkaline soil, which would mean likely alkaline water too, you could consider looking for an alternative berry. I have heard, not verified for myself, that serviceberries taste similar to blueberries and may do better in your conditions. If I wanted to grow blueberries in my limestone based soil with limestone in the water, I would have to do it in an oak half barrel. I would have to use peat moss, and would likely add acidified cotton bur compost. I would have to use a 5 gallon bucket to water it so that I could mix the vinegar in, too. It seems like a lot of work to me when there are so many other wonderful berries out there.

If you're going to acidify your irrigation water (whether with battery acid or vinegar - doesn't really matter) you'll need to experiment to determine the proper treatment. Watering with over-treated and highly acidic water isn't going to do anyone any good. Get some pH strips and do it right. But your soil pH is then going to depend on how often you water, and may bounce up and down.

I think the bottom line is that managing soil acidification by acidifying water and with soil amendments is real hard.

By the way, it's a debunked garden myth that pine needles and oak leaves will lower pH.

Juneberries are nice but nowhere close to blueberries. Too mealy, too bland. I have access to two trees (not mine), they are biennial, and the birds clean them up from one day to the next. One is a tree that bears easily 20,000 berries in odd years, and the berries are still gone in one day.

Honeyberries (haskap) are half way between the two in taste. But if the OP can afford a tree instead of shrubs, a good mulberry is hard to beat. both have a bird problem, but blueberry and haskap, being shrubs, can be netted with some effort. Juneberry is a small tree and it is too difficult to net.

Your original plan will surely work. Use sphagnum peat moss, pine bark fines and some compost. Lower ph every watering to 5 and use ammonium sulfate once a week during the summer.

I would also get a good soil ph tester.

I grow bb"s in ground and in pots and both do well but the ones in pots are easier to manage. I did the exact thing you are proposing to do and worked out perfect. You can change the ph easily and keep it there. I wouldn't spend the money on raised beds spend it on bb"s

But as noted, the original plan certainly won't work if the irrigation water is alkaline. There are workarounds, also as noted, but it won't be easy. A good soil pH tester seems required.

That's why it was mentioned that at every watering the ph needs to b adjusted.

And that's why it was mentioned that it won't be easy.

I have been growing blueberries in pots for years, the plants are healthy and produce well.

My mix is probably 80% peat and 20% chopped leaves, a little pine bark, and a scoop of garden soil. Don't remember if I tossed some sand in, but don't think so.

I rarely have to give supplemental water, but when I do I don't worry about acidifying it. I do use fertilizer for acid-loving plants or specific blueberry food, whatever I managed to get on sale.

I guess I have been lucky!

Pots may be the best way to go. You can control the pH much easier than if they're in the ground. It's common practice in sounterhn California where our soil tends to be alkaline, and we put a couple of bushes in an oak barrel. You can also grow them individually in 15 gallon nursery pots. You can make your own potting mix or use a bagged azalea mix.

Growing blueberries

gardengal,

"plant roots grow out laterally (not down) "

is this just in reference to blueberry's propensity for shallower roots or is this for most other plants with deeper tap roots too? Thanks.

I believe digging 2 feet deep is more than enough, because blueberry plants have a propensity for shallow roots (no tap root). I only amended the soil 1 foot deep for my blueberry garden beds. Every spring and fall, I add fertilizer designed for acid-loving plants (half portion in the fall) and throw some pine bark mulch on top for it to compost over time. I've been told it takes time for the fertilizer to break down and get to the roots so budget adequate time. I use Sunshine Blue blueberries which tolerate a higher pH, so those are the only things I do differently for these plants verses the others in my garden.

Wow thanks for all the replies. I am going to think about this. I do have an overabundance of rainbarrel water so i could water them exclusively with rainwater.

Is a tester like this used with distilled water not considered "good" enough?

http://www.leevalley.com/en/garden/page.aspx?p=65366&cat=2,42578,65366

Is there really any difference between a raised bed and a container? A raised bed is just a container with an open bottom is it not? In my mind the only difference is that worms can come up into one but not the other.

I have a normal 50 gallon rainbarrel that was cut in half to make two planters. Would that size be good for each blueberry plant? I guess that makes them 25 gallon pots so i assume yes.

I've heard of haskaps. i'll look into them too.

"I've heard that adding a substantial amount of pine needles to the mix would help with this problem."

With what problem specifically? Lowering pH? Unless considering a truckload of fresh pine needles, there will be no pH change to speak of at all.

Also, this is an old and inactive thread. You would be better off starting a new one of your own.

Then when you get your blueberries producing...guess what? Robins love the berries and tend to pick them a day before you pick them.