If you want a water soluble fertilizer, Miracle Gro All Purpose is suitable (mostly urea & no nitrates). Alternatively, as you mentioned, there's the Miracle Gro product aimed specifically at acidic soil adapted plants as well as JR Peters' Jack's Classic Acid Special (probably the best choice of the the three in terms of quality). In general, a weekly or bi-weekly application at label rate should be fine for all of these.

Miracle Gro's Shake 'n Feed for Flowering Trees & Shrubs should be a good choice if you prefer a granular, slow release product (I'm trying it for the first time this year). It contains no nitrates, has an NPK ratio of 3-1-2, provides a few trace minerals, and is relatively easy to find (I purchased mine at Wal-Mart). The Hyponex fertilizer that you mentioned should also be fine. I recall that several experienced blueberry growers who used to frequent the Fruits & Orchards forum routinely used water soluble ammonium sulfate with very good results. That being said, blueberries are very sensitive to overfertilization, so be sure not to overapply it.

Came across this article online. http://www.livinghomegrown.com/how-to-grow-awesome-blueberries-in-containers/

That article is better than many that I've read about growing blueberries in containers, and the advice to feed lightly and more frequently is very sensible. Nonetheless, the notion that you can maintain the proper potting mix pH with fertilizer alone is debatable, particularly if your water source is alkaline (as so many are). Additionally, the suggestion that you should use organic fertilizers because "you don't want chemicals in your food" illustrates an all too common misconception about the difference between organic and synthetic fertilizers while completely ignoring the possibility of pesticide residues and other potential contaminants in organic fertilizers (arsenic in the feather meal that she recommends, for example).

I never raised Blueberries, She seemed to have experience growing them. Gradual feeding is pretty common for all plant propagation. You may find low contamination organics or CRF Acid fertilizer. Not sure what Blueberries like as far as nutrient amounts annually. 1 gram of Nitrogen annually(0.1 gram monthly) per Liter(or Quart) is commonly used. Thats about a heaping 1/2 teaspoon of 4 to 6% N organic fertilizer per each liter(or quart) of container capacity. For a CRF divide 0.1 gram by the percentage of Nitrogen in fertilizer, Then multiply by the number of months of release.

Example using Osmocote Plus at 15% N 1tsp=5grams

(0.1/0.15)*6mo= 4 grams approx 1 tsp per each Liter of container capacity. Apply every 6 months. You can use less like 1/2 to 3/4 the amount for each liter, and see how the plant responds. Osmocote specs recommend 2.4 grams/liter for sensitive plants, 4.7 grams/ liter normal feeders, 7 grams/liter heavy feeders.

Addition: Water in my area is pH 7.2 to 7.5. adding 1 Tbs 5% vinegar to a 2 1/2 Gal bucket lowers water pH to 5.8 to 6.0. Also using Organics "Dr Earth All Purpose 4-4-4" on 20 shrubs (8 Rooted 2nd year Hibiscus Cuttings, 11 Indian Hawthornes 2nd year from seed, and 1 Manzanita "Emerald Carpet" 2nd year layered cutting) in #1 (3L)Containers. Using 1/2 to 1 tsp fertilizer per week per container. All showing steady but not excessive growth, with good leaf color. Hibiscus Blooming Steady already. Soil Mix 2:1 Redwood Shavings:Pumice, No Limestone added. This might be a good starting point if you want to use Organics on Blueberries, just use a Fertilizer for Azalea and Rhodo's Organic.

Fertilizer Ingredients Listed: Wild-caught Alaskan Fish Bone Meal, Valley Grown Alfalfa Meal, High Country Feather Meal, Naturally Mined Potassium Sulfate, Cold Water Kelp Meal, MicroActive™ micronutrient-rich Seaweed Extract (synergistically boosted with micronized humic acids for maximum bioavailability). Beneficial soil microbes and eighteen select strains of ecto & endo mycorrhizae

dale what do you use to measure pH?

Found another Blueberry Fertilization guide that also includes a Ferigation Chart. http://articles.extension.org/pages/29213/blueberry-fertilization

Osmocote Plus contains Nitrate N, so you want to skip this CRF.

Actual Nitrogen per Acre is divided by 2 to equate to PPM. So 30 lbs Nitrogen per acre is equivalent to 15ppm N. These are very low rates of Nitrogen. This would be .022grams N/liter per year or 0.069lb N per 100sqft. It seems Blueberries are very sensitive. The previous organic fertilizer recommendations may be way to high . Have to rethink this.

BahamaDan- I purchased a pH and TDS pen combo online. I added Vinegar to a Liter of water 1/4 tsp at a time and recorded the pH to get a references.

http://www.amazon.com/HDE-Toolbox--Temperature-Salinity-Hydroponic/dp/B00IEJOI9S/ref=sr_1_18?s=lawn-garden&ie=UTF8&qid=1444012466&sr=1-18&keywords=ec+meter

Edit: I have a color blindness problem so meters only for me.

Dye indicators like General Hydroponics pH Test Kit are a simple and affordable alternative to meters. For blueberries, I prefer this Bromocresol Green pH Tester because of its higher accuracy at the lower end of the pH scale (4 to 6).

Dale - For your pH tester, what are you using for your probe storage solution?

ewwmayo- No storage solution used :-0. I didn't know about that.

You can use pH 4.0 solution (the low side pH calibration buffer solution) in a pinch! That's what I'm doing. Don't let the probe dry out and never store with distilled water.

Just haven't gone out to buy the right stuff yet, was hoping you had tried it.

One more site, more in depth article. Plus explains Plants are very Endo mycorrhrizal dependent.

http://www.spectrumanalytic.com/support/library/pdf/Fertilizing%20Blueberries.pdf

Excerpt: Spectrum Analytic recommendation is a flat 65 lb. N/ac for blueberries. We don’t distinguish between young plants and mature ones because we simply have no practical way of identifying the age of the planting and adjusting the N recommendation accordingly. However, we agree that young plants should receive less N than mature ones. Some authorities recommend N rates up to 140 lb. N/ac for mature plants. Most of the highest N recommendations are located in the Western states. The following table gives an example of some N recommendations made by various University Extension services

So if they are estimating 1000 plants per acre, thats 6.6ft apart, 43.6sqft per bush. 65lbs N/acre annually average. Estimating each bush receives 1/1000 the amount of N 65 lbs/1000 is 1oz N per Plant per year. To be safe start at 1/4 this amount or .25oz N per Bush. Dr Earth Acid Fertilizer is 3-4-3 so at .25oz N this is .25/.03 = 8.3 oz 3% N Fertilizer per year (0.7oz/month). Thats about 2TBS per Month per plant at Fertilizer density of Sp=0.67. They recommend Potassium Sulphate as the K source which is in the fertilizer. So this is a questimate only maybe start at 1TBS per plant for the first month to watch the response. Then you can increase gradually as needed to find the best amount. Maybe others with more experience with Blueberries can give more info. I hope it works, keep the group informed how the Plants are doing, this will help expand the Knowledge Base.

Dr Earth Acid Fertilizer is 3-4-3 Ingredients:

Rich in:

Wild-caught Alaskan Fish Bone Meal, Valley Grown Alfalfa Meal, High Country Feather Meal, Cold Water Kelp Meal, Mined Potassium Sulfate, Elemental Sulfur, MicroActive™ Micronutrient-rich Seaweed Extract (synergistically boosted with micronized humic acids for maximum bioavailability). Infused with Advanced TruBiotic® – consisting of “Five Champion Strains” of beneficial soil microbes and eighteen select strains of ecto & endo mycorrhizae Target pH 5.4.

Ideal for:

All acid lovers, maples, camellias, azaleas, hollies, gardenias, hydrangeas, evergreens, ferns, shade plants, tropical plants and all berries.

Sidenote: Whatever soil mix you decide on, eliminate adding the limestone. You can also investigate the fertigation approach for fertilization also. Just use the best ingredients for the mix (ie ammonia based N, Potassium Sulphate instead of Potassium Chloride,and SuperPhosphate added to soil mix). The article has fertigation amounts, might start in the range 10 to 30ppm N. If you want to supplement N with 21% N ammonia sulphate 10ppm N is 10/(21*75)= .006oz/Gal or 0.19 oz(about 1tsp) per 30gal Trash Can of water. You see how low this is. MG All Purpose 24-8-16 contains Potassium Chloride which is questionable. Maybe look for something similar with a different K source for Blueberries.

Sidenote 2: You can also make concentrated Stock Solutions( 1% to 5% N for example) for easier measuring to a watering can or siphon mixers. Many Hydroponic sites have info for making custom fertilizer solutions.

ewwmayo- just rinsed with distilled water, and placed the cap on. The instructions did not mention any solution. Thanks I will look into that.

Edit: I just noticed my other meter was TDS only, Haven't used it yet. EC would be better as you mentioned.

Dale - Here's a handy link by Hanna (very good manufacturer): Tester Care

BlueBerry Fertigation Chart from article

Using 1 acre inch of water as 27,154 gallons and 8.33lb per Gal. The range is about 2 to 9 ppm N solution per week. At the ratios used in the chart the 65lbs N/acre annually figure is equivalent to about 11ppm weekly. I noticed the N/acre annually divided by 52 is different than the recommended weekly amounts.

Addition: Excerpt from Article

Plant Root Systems and Mycorrhiza Fungi: Blueberries have a somewhat unique root system. The roots
do not have “root hairs” like most other crops. Root hairs are single cell extensions from the root surface that
greatly increase the absorption surface of the root, and therefore absorption capacity of the roots. The lack of
root hairs on blueberry roots would be a serious disadvantage to survival, especially in the uptake of immobile
nutrients like P, except for an adaptation that the species has evolved. Blueberries have compensated for the
lack of root hairs by evolving a symbiotic relationship with vesicular-arbuscular mycorrhizal (VAM) fungi in
the soil. Mycorrhizae are soil fungi that form a symbiotic association with plant roots. The thread-like hyphae
of the fungus connect with plant roots and extend into the soil. The hyphae act like extensions of the plants root
system by absorbing nutrients and transporting them back to the plant roots. In exchange, the mycorrhizae
receive sugars manufactured by the plant. A major benefit for the blueberries is an improvement in P uptake.
While mycorrhizae can infect most plants, they typically are more of a benefit to woody species than
agricultural row-crops or forages. It has been demonstrated with agricultural crops that the benefits of
mycorrhizae decrease as the soil P level increases. In flooded soils, mycorrhizae may die. If the soil has a
low level of available P, the loss of the Mycorrhizae may greatly decrease the crops ability to absorb
enough P. This effect has been seen in wheat following flooded rice crops.

Hi all, for your blueberries in containers, how do you supply calcium to them? None of the fertilizers mentioned here contain calcium which apparently is an overlooked mineral for blueberries. I recall reading Ernie's post somewhere, he mentioned someone using Tomato fertilizers for their blueberries since they contain calcium. I've used gypsum but I'm looking for alternatives, something with less guesswork. I started this thread here: http://forums2.gardenweb.com/discussions/3877272/m=3/when-to-replenish-gypsum-for-blueberries-in-large-containers 

Thanks Jay, that was very helpful. I forgot to think of the calcium content of our hard water, of course! Miracle Grow Acid Shake N' Feed looks great, as was suggested by Ernie as well, with a 3-1-2 NPK ratio. Where do you buy it in LA, though? It's not available locally at any HD, Lowes, or Orchard Supply, according to their websites. Armstrong carries exclusively organics, IIRC. And Jack's Acid Special? I'm guessing it's available at some hydroponic places? I'd order it off Amazon, but recently they changed the minimum order to $49 for free shipping so it's become less useful for me.

Is my MirAcid (water-soluble 30-10-10) no good because it's derived from KCl and has no sulfur for acidification? I still have a 5-lb can, though it can use it for my camellias and azaleas. My plan now is to scratch a little MG Acid Shake n' Feed to the soil mix and fertigate weakly with MirAcid. The K in MirAcid is a little low, but at least there is nothing in excess like with so many other fertilizers. Do you think that would work OK or is the KCI in MirAcid fatal? My blueberries look OK and are fruiting. Some leaves are showing fertilizer burn because of my heavy hand (or at least I think so, red around the leaf tips) - so I'm just flushing the soil (which is easy to do w/ a fast draining 5-1-1 mix) and not fertilizing right now.

FTG,

Yes, KCl in MirAcid is fatal for blueberries (bb). Plus it has 3% nitrate nitrogen (http://www.miraclegro.com/smg/products/Miracle-Gro/pdf/Azalea_Cam_Rhod_Food.pdf) which is other no-no for bb. How many bb plants do you have? I use Peter's Professional Acid Special 21-7-7 (http://everris.us.com/sites/default/files/e99330.pdf). If you need only a small amount like 2-4 lbs, email me.