If it were me, I'd probably use peat moss and Nature's Helper (composted pine bark fines) or maybe just Nature's Helper and forget about the potting mix and perlite. Be sure to plant on a berm to avoid drainage issues if you plant them in the ground. I think Home Depot and Lowe's sales Nature's Helper.

Just for curiosity, why are you keeping them in containers? Seems like more work (watering, etc).

Pine bark gtound finer than the decorative type is called "soil conditioner" at Lowes or Home Depot or elsewhere. It is usually perfect size for making potting soil, though does vary a bit brand by brand, batch by batch.

I may have misunderstood. Soil conditioner would go in the soil, as part of the potting soil. If you are looking for something just to top it off the decorative types are fine, from 3/4 inch up to ~2 inch pieces. They reduce both heat in the soil and evaporation from the soil. The larger chips discourage "la kitty cat" from using the pot as a litter box too.

They are potted up because I intend to sell them locally and at the farmers market. I'd say the mix I have made up is 75 % peat already. So maybe that will be enough. I recall seeing the "soil conditioner" although I never paid attention to it's contents. thanks! I'll go look for it and the other as well, see what is most economical for my needs.

Degrandchamp Nursery, a source I used to use for blueberries, and a very large commercial supplier, use (or used to) as potting mix for their blueberries 50/50 by volume fine sand and peatmoss. I don't know if they used a wetting agent but if you don't- make sure you pre-moisten the peat. That doesn't answer your question but that's already been done. Thought this might be simpler for your next batch.

soil conditioner = Nature's Helper (a popular brand) = composted pine bark fines

"...the mix I have made up is 75 % peat already. So maybe that will be enough." Or too much?

Brandon7,

Texas A&M recommends growing your potted Rabbiteyes in 100% peat. So, his 75% is probably ok.

Here is a link that might be useful: Blueberries for Texas

Here are some possibly helpful links:

Dave Wilson's recommendation: http://www.davewilson.com/homegrown/promotion/blueberries.html

Gardenweb discussion: http://forums2.gardenweb.com/forums/load/fruit/msg0521413425698.html

Gurgler,
The biggest issue would be drainage. It might be do-able, but I don't think pure peat or even 75% would be optimal. I don't have the links handy, but there have been more than one thread on here with people saying they didn't have good luck with pure peat for this application.

I too had heard several growers using 100% peat with success. But I didnt have enough for all my containers. The pine bark would serve as a mulch to encourage the proper PH.

I would run with the commercial grower that is turning out thousands of plants over anyone else. Top rated graduates tend to go to the private sector- second stringers tend to go academic- at least in the field of agriculture. Degrandchamps would probably use less sand to reduce shipping if it produced plants as quickly. Just a guess.

What would make Dave Wilson Nursery expert on blueberries?

I'm not sure if you are asking or are using your comment and question to point out that they are likely to be experts on the subject.

If you were asking, they are commercial growers of blueberries like you just said you would tend to "run with". Ed Laivo, who wrote the article for the website I linked above, is well known through many professional and academic circles as being a fruit "expert". He gives many lectures to Master Gardner groups, professional grower organizations, etc.

Harvestman makes a good point about the nursery he was talking about would use less sand if possible. A mixture of 50/50 sand and peat would take care of the drainage issues. That is the same mixture I use in my bogs and it works well.

It sounds like Dave Wilson Nursery's recipe (and lots of other nurseries similar mixes) or Degrandchamp's 50/50 mix would work pretty well. Try both and see what happens. Let us know your results!

Dave Wilson nursery produces their own blueberries? Never seen them advertised in any of the trades. I thought they were located in CA. Guess they could be a multi-state operation but if they are a commercial supplier of blueberries I'm surprised I haven't heard about it.

Harvestman,

I don't see where anyone said anything about other states? Dave Wilson grows their blueberries in California. I don't think they have any actual production outside of California where they are based. Many blueberries can be grown in California, and as a matter of fact commercial blueberry fruit production in that state has grown very rapidly in the last few years. There are close to 5000 acres of commercial blueberry fruit production presently in the state.

Maybe I am just taking you wrong, but it seems like you are trying to say something without saying it. I'm certainly not claiming to be any type of expert on blueberries. All I know about them is what I've learned from growing a small number plants for the past couple of decades and what I see on the internet. DWN and some of their employees are fairly well respected by many in the industry and in educational circles. If you want to dispute their credentials, fine, but just do it, don't hint at it. Maybe you know things, or lots of stuff, about them that have no clue about. All I know about them is what I read online.

I do know a little about soil and about soil drainage, and I think my input above was valid. If you don't think so, maybe you could specifically state why.

Here is a link that might be useful: Dave Wilson Nursery's Blueberries

My only point of saying it was probably ok was that there are apparently other folks that recommend 100% peat and it apparently works for them. I personally have 1/2 peat + 1/2 pine bark mulch + 20 lbs Green Sand, and then pine bark mulch on top in a half whiskey barrel for my blueberries. The Dave Wilson mix seems good too.

1/2 peat + 1/2 pine bark mulch
=============

That's about what I use too for rabbiteyes, with a bit of gypsum or if I didn't have that around some very small amount of lime just for the calcium. I feed it with cottonseed meal. They get sprayed with Peters (for an N boost and trace metals) or iron once in a blue moon, in no regular manner.

Now that I think of it, I have given them a little chemical azalea fertilizer every several years, as I happened to have some extra around.

Brandon, Ok, I admit to not being a fan of Zaiger and DWN. I once sat through a sales pitch made by 2 charactors who were sales reps of Zaiger at a fruit growers conference. It was like an hour version of one of those "slices, dices" miricle products ads on late night TV. Pure mindless boosterism by 2 men who actually knew nothing of plants and soil.

I've also had poor success with Pluots here in the northeast and am suspicious that the whole name Pluot is a promotional sham and these are only new varieties of J. plums. But that's all nither here nor there, of course.

Dave Wilson does not list blueberries in their commercial catalogue and so I'm thinking they don't serve the commercial BB industry because they only sell them through their home orchard division.

I googled this fellow Ed Laivo you mentioned, and all information about him was directly linked to his employment to DWN. Is he really a widely respected authority? I don't have any idea, but I've never heard of him. That doesn't mean that he's not extremely knowledgeable. My hunch is his suggested mix would work just fine- I just would put my money on the Degrandchamp formula because I believe them to be a much larger player in the blueberry industry than Dave Wilson.

Now that I've answered you, how bout explaining your defesiveness for DWN- are you an employee perhaps, or did you just feel I was bullying them?

Being naturally skeptical about things is a very good thing. Letting the skepticism cloud your viewpoint probably isn't.

I still don't know what the "I thought they were located in CA. Guess they could be a multi-state operation..." was about.

So far as Ed Lavio goes, maybe he's an expert; maybe he isn't; I don't know. But, since he represents a reasonably large commercial grower, since he's invited to give talks at so many places all over the country, and since his recommendations seem to match those of many others, I think that lends some credibility to them. I certainly wouldn't dismiss Ed's recommendations just because you once ran into two salespeople from the company he works for that seemed not to be experts.

Seems like you want to take your frustrations from the growers conference out on my contributions to this thread. If there's something wrong with something I say on gardenweb, I'd love for anyone to tell me. That would allow me to learn. But I don't get much out of someone attacking my post or anyone else's because of an experience that seems to have very little to nothing to do with the topic.

If I was an employee, I wouldn't have said "All I know about them is what I read online." If I was an employee, I would probably live in CA instead of TN. If I was an employee, I'd probably have more experience with blueberries than I stated above. I just don't understand your desire to dismiss their recommendations seemingly without reason, and I'm over having to try to defend someone because of some fairly unrelated experience you once had.

Brandon, exactly why do you feel you've been attacked? This internet doesn't do much of a job of conveying a twinkle in ones eye. Maybe if it did, you'd realize my stated opinions are not meant as attacks at anyone.

I do have a negative opinion of big nurseries that use current American business marketing techniques that insult our intelligence- even if we deserve it. I have old fashioned ideas about ethics and when I feel those values are violated, as they are routinely in the modern corporate world I get annoyed- I'm so tired of being lied to. That's how I felt when those 2 salaried sales reps gave their talks. It was a reflection of the ethics of the whole company.

This is why I never considered working for companies such as these- which isn't to say all large companies are necessarily bad or unethical, or that I imagine a world of small companies and small farms ever being the model of a modern country.

It does mean that I like to take my business to smaller nurseries as much as possible and buy my food from small farms. It has been my experience that the people involved in these smaller companies lie to me a lot less and seem to model their behavior to an ethical model I appreciate.

Harvestman,

First, I think if you re-read, you'll find that I said I felt like you were attacking my contributions not that you were attacking me. There's not a lot of difference, but there is some. When you question my source, without even directly addressing the issue at hand with your skepticism, then you are in effect questioning my input. Your comments would lead any reader to conclude that you would not value my source! If you think there is reason to question the input from a source, it would be best to state some valid reason the information might be incorrect instead of using some indirect argument that tend to cloud the discussion and bring up questions about the character of the source rather than stating what might be wrong with the information.

If you wanted a forum to vent your feelings about DWN, maybe you should start another thread instead of using my contribution as an opportunity to release your pent up frustration with current big business practices. You've used all kinds of arguments to discredit my source including the state from which they were based.

I think we should get back to discussing what type of growing media should be used for container grown blueberries. I think my initial recommendation of a mix made from composted pine bark fines and peat is an excellent suggestion. If I were going to grow blueberry plants to sell, as the original poster indicated they were, I'd test both that mix and a peat/sand mix like DeGrandchamps and see which one worked best for the specific application. There is likely not a single best solution because of multiple variables. Container size, environmental conditions, amount of time the plants will be grown in the media before transplant, watering practices, type of blueberry, and other variables may impact which mix works best.

Brandon, you are too much! I make my own potting mix for hundreds of 15 gallon potted trees and I believe that sand or perlite or both are absolutely essential to achieving adequate drainage in a pot. This is a professional opinion and when Cornell came up with the peat-lite mixes in the 50's that revolutionized potted culture they started with peat and sought to improve it.

If there are other professionals- even much more qualified professionals who disaggree with me that's fine. These threads are open to everybodys individual opinions and creativity and you shouldn't be so sensitive, if you're advice is valid it will shine through and if it doesn't- no big loss. When I disaggree with what you say I'll continue to state that and embellish as I please and I will be greatful for everyone else who does the same.

Sorry that my post has sparred the two of you gentlemen on...time to kiss and make up ;)

I purchased large bags of pine mulch (ground pretty fine) it looks to the perfect size for topping off my container plants. Which by the way are in 3 gallon nursery containers. I also picked up a few bags of the soil conditioner (90% composted pine bark fines) which I will use in my next batch of mix. I have another 200 plants arriving this week...so I'll have a chance to try out a few different mixes.

Also BTW, the plants I have recently planted in containers are all Tifblue (rabbiteye)

The ones I'm getting are also rabbiteye, alapaha, powderblue, brightwell and tifblue. Hopefully most of them will be sold soon, and what's left will go to the farmers market and what's not sold after that could be in container til next year.

I hope someone is spurred on to actually do a side by side experiment with blueberries planted in alternative mixes. I've stopped growing blueberries in my nursery, so it won't be me.

Brandon- how about you? You could probably get results by the end of the next growing season. If your mix works best, I'll pay you for the plants. I trust you'll handle the results honestly.

rginga, don't be sorry. I, at least, have fun with this kind of thing. I try to concern myself primarily with relationships that are connected by more than the internet.

The debate here finally got my tired old brain fired up and I think I've figured out the recommendation of 100% peat as a growing medium for blueberries. It is a regional recommendation based on the alkalinity of available water.

A porous well drained medium would require more frequent watering,no? More alkaline water would drive the pH medium up to the detriment of the plants. So the compromise would be to lower drainage and water more carefully.

If you live in an area with substantial summer rain or with neutral to acid water supply you'd probably be better off with the better drained potting soil. In the West, an all organic medium would probably be the ticket.

Rjinga,

Don't worry about the debate. Like Harvestman, I somewhat enjoy a little debate on here. It's not really the debate I enjoy, but the chance to get information out and correct and the chance to think about things that might otherwise be taken for granted. I do prefer to stick more to the facts than to feelings, but overall I think this conversation has been helpful. Maybe I even got Harvestman's gears turning a little (or maybe they just started turning on their own, who knows). Although I still don't understand the basis for some of his opinions, it's good to have someone throwing out ideas that make you think. The important thing is that you received answers to your question and have food for thought as you test different mixes to see what works best in your particular situation.

Please do let us know your results if you can remember to get back to us on it. You might also consider evaluating some other related things like container size (especially depth), different mix ratios, watering frequency required, etc.

Brandon, here's my kiss. I did go into overkill about rejecting your suggestions, although I didn't realize it until I went over the posts.

Upon thinking is over it wasn't the source of information that was irritating me, it was the info itself. It was so counterintuitive that a pure peat mix would be as affective as a well drained mix. It's so hard to really know anything in horticulture and so much research is not really reliable because of all the variables of soil and climate (and even water sources). But in the end, I like to know about the research.

I should have looked up the Texas U. link that you posted, maybe it explains why instead of just how as the DW site tends to. Any way, I apologize for being a carmudgeon and I appreciate your input. However, I will continue to force people to read my crackpot philosophising if they read my posts.

Harvestman,

Thanks for your kind words, but one thing that I think is important for me to point out is that DWN doesn't recommend pure peat. I question the pure peat recommendation just as much as you.

"I will continue to force people to read my crackpot philosophising if they read my posts."

Hear! Hear!

I like opinions served strong, so long as they are clearly opinions, and especially when based on long experience. It is part of why I like reading MG Kain's old gardening books.

Brandon, right, that wasn't your post about Texas A and M recommending 100% peat but you did recommend an all organic mix, right? No sand or perlite, which would presumably have similar drainage issues, wouldn't it?

When considering the mix, one should also consider whether it's intended for a pot or ground. A pot only has holes in the bottom, and soil drainage will be more critical to avoid being saturated. I found peat heavy mix contains too much moisture for my blueberries and I have to really watch my watering. Including some sand/perlite greatly improves that. In the ground, water can dissipate both sideways and downward, and moisture level can be more even. If one really has the drainage issue, using sand/perlite won't help much since the water will just collect at the bottom. Also one usually needs more mix for the ground planting and some material like perlite will be overpriced if sourced from typical garden centers.

Finally soil is a constantly changing media. What's best for now may not be best for the future and vice versa. I include some bark mulch in my mix. It provides some structure and over the long term, it decomposes and provide the nutrients. But for the short term, it robs the soil some nitrogen and I have to compensate using other ways.

Nature's Helper (mostly composted pine bark fines with some sand) was my recommendation. This is the same or similar material that much/most nursery stock is grown in. It will drain very well without additional sand or perlite for quite a while, but eventually, as tc88 alludes to, it will further break down and will need to be replaced (which would need to be done anyway, not just from a drainage standpoint). Tc88 hit the nail on the head when he said "soil is a constantly changing media. What's best for now may not be best for the future and vice versa."

I think we are all on about the same page with this. Now all we have to do is wait for the results in a few years. (-:

Here's the thing, perlite is more expensive than pine waste and sand is expensive to move around but everyone I know in the nursery business uses perlite and/or sand in the mixes they use to grow their plants. I'm on the east coast so maybe this is a regional predjudice but I've tried potting mixes that were all organic material (a little sand will accomplish nothing, needs to be a third by volume, at least). Compare those with something like Sunshine Pro-mix and most plants will grow better in the pro-mix in my experience. I have compared results although we don't have the specific product here you mention.

Big box stores like Home Depot sometimes don't have a good potting mix although Miracle Grow potting mix isn't bad. Greenhouse suppliers usually recommend a "pro-mix" with mineral drainage enhancment.

Most nurseries around here grow plants in similar mixes to Nature's Helper. When I think about it, the only place I remember really seeing perlite used in mixes for shrubs and trees are mail-order potted plants and big-box stores. My local high end nurseries don't use it. That doesn't mean it's not great stuff, just not required for all situations.

As for the sand, it depends on the pore size of the remainder of the mix. In a clay soil, 1/3 sand would not improve drainage. However in a mix like Nature's Helper, this is not the case. Similar organic mixes can have excellent drainage without containing perlite or being comprised of a very high percentage of sand. But, as was mentioned earlier, organic soils do change over time as they break down.

BTW, the same type of thing applies to perlite as to sand. Mixing a little perlite into clay won't change net drainage.

Finally, it sounds like I'm pushing Nature's Helper, and I don't mean to be doing that. It's just a brand that a lot of people are familiar with. I'm sure there are other brands with similar consistencies.

There ought to be standards for rating drainage that are revealed on the packaging of potting mixes. Anecdotal observations can only take you so far. In Ca. where you don't deal with rain during much of the year, drainage is probably not a big issue (although I find a very light mix works best for vegetable seed starts in a green house). I have seen an Aug. here where we got 26 inches of rain- spread out through the entire month.

But it certainly is possible that they've found a way to process pine products to create a great draining mix.