I've grown blueberries in containers for the past few years. That is necessary here because the soil has a pH over 8, the soil is clay, and there are lots of gophers, so pots are really the only alternative. I have 40 southern highbush plants (about 10 varieties) that require little if any winter chill. No frost here. I had great enthusiasum when I first got my plants, and every day I'm still excited when I deal with them, especially when picking the fruits. I plan to get a few more plants next year as well. My plants are doing extremely well, and I havent killed any yet. Most are in 10 gallon plastic containers, with some in 15. I prefer the larger shorter containers, but the cost of pots is great, and the 10 gallon containers were a gift from a friend. And 40 plants take a lot of mix. The mix I use is merely some home-composed ground wood chips from junipers and a mulberry tree, and all their leaves. These were several years old, and had lots of leaves and fine stuff in them. And I screened it all through half inch mesh so it's both fine and drains well. It's basically a course compost, and it was free. I think almost any commercial mix would do however. From my experience what is more important is the pH of the water. I acidify mine. You can use vinegar as someone above mentioned, but you can also use other acids as well. I myself use dilute (new, uncontaminated) sulfuric acid as do many local commerical nurseries. I buy it in automotive supply stores as battery acid. (be very careful with respect to safety, always add acid to water, and dont use such a chemical unless you know what you are doing, etc). I am thinking of investigating using citric acid if I can find a reasonable place to buy it. I use litmus paper I got on ebay to make sure the pH of my solution is right. I aim for about 5. Once you have your formula down, you dont have to check often. I mix my watering solution in standard plastic garbage cans that hold 32 gallons. I have 3 so I dont have to walk so much to irrigate all my plants which are grown in 3 different areas. I also add about 1/4 to 1/3 cup of soluble fertilizer to every new garbage can full of acidified water. Most often I use inexpensive ammonium sulfate, and sometimes for trace minerals I'll add generic miracle grow, and on occasion toss in some epsom salts for magnesium (which my berries seem to need). I'll also add chelated iron solution when they look like they need it. I have no specific schedule for this however, and just trust my eyes and experience. I was warned that fertilizing so often and encouraging fast growth would not be the best path to follow. I have had no problems at all because of it - just large vigorous healthy plants and lots of fruit. But then I have experience and a good eye for how a plant is doing, and make adjustments as I go. I use the acidified water about every 3rd time I water, and use tap water the other times simply because it takes less time. In the summer I have to water every day to keep the plants healthy. This year I'm going to shield my pots from the sun so maybe I wont have to water so much, and the roots wont be subject to such swings in temperature from the daily sun - that cant be good. I'm planning on sinking them about 6 inches into the soil, and then mounding cheapo mulch up against the upper part of the pots. I still want them high so they are easier to pick. My plants are doing very well, the leaves are large, green, and lush. The plants have grown quickly, and the only real problem (besides taking a lot of time for care) is keeping the birds away from the yummy fruits. Read as much as you can, then relax and go for it. They will bring great pleasure into your life.

Al, I've appreciated the thoughtfulness and vigor with which you approach your subject and have learned a lot from you while browsing these forums. I have around 300 plants in containers, in and outdoors, orchids, ferns, common junk stuff, lots of epiphytes on wood, begonias, vegetables, maples, succulents, cacti, etc. I haven't given them a lick of inorganic fertilizer in three years and would agree that the results can be mixed. Lately I've been brewing my own actively aerated compost tea using homemade worm compost, kelp emulsion, a handful of good garden soil, and a few other organic additives in small amounts. This mixture is aerated and vortexed for 18-24hrs during which time the microbial populations multiply, making a rich actively biological soup. I use this regularly on all my plants, and fertilize between compost tea applications with organic seaweed or fish emulsion type fertilizers. I also keep a small anaerobic compost tea brewing and I'll use small amounts of this every month or so. Since I've started using the compost tea my plants have all seen a remarkable uptick in both foliar growth, blooming, and just general "health" as compared to just organic fertilizers. My take on it is that the compost tea supplies a steady stream of microbes that the plants can symbiotically partner with to convert the organics into usable nutrients. I totally agree that good drainage is key and if the soil is too heavy the compost tea can quickly turn anaerobic in the pot and result in all sorts of problems. A fast draining mix combined with regular compost tea applications and organic fertilizers seem to have a lot of advantages and to keep my plants reasonably healthy. I can't tell you exactly what proportion of NPK the plants are getting, instead I rely on an entire ecosytem with all of its sloppy redundancies to allow the plants to orchestrate their ancient microbial dance and get what they need. I understand that chemical fertilizers work, it's just the widespread and longterm impacts that these substances have on the larger ecosystem (gulf dead zone, algal blooms, groundwater nitrification, etc) that makes me want to avoid them, even for container culture. Nurseries are large contributors in this nutrient-pollution overload, but if you add up all small-scale homegrowers who put miracle-gro on their tomatoes it equals a whole lot of nutrients that are being converted from fossil fuels and released into our larger environment. Historically nitrogen has been a severely limited nutrient on the earth, thus the biosphere's incredibly tight hold on it via the humus and soil building processes. I totally respect that you seem to be solely interested in what's best for the plant when it comes to container culture, and I agree that inorganic fertilizer do yield amazing results. But I believe we need to think beyond the individual plant, to the ecosystem in the pot, and then to our wider community or plants animals and humans that we share our planet with. We can (we have the choice!) develop new technologies and techniques that allow us to avoid the use of chemical fertilizers that imbalance our environment and tax our natural resources and instead rely on the built-in recycling and life-support systems of the greatest systems engineer imaginable, mother nature.

yeah, ken...I told you I was brain dead...perhaps I was distracted by the rather amusing hosta forum video on how to extract a hosta from Don R.'s pot to give it back to him...THAT was 'garden soil'...and perhaps I was just disgusted AND distracted by how badly astilbes 'thrive' in my garden b/c it's just probably TOO dark & too full of CLAY....*sigh*...thanks for letting me RANT... I'm going to go home to my poor astilbe after school & rescue it. Thanks for responding so quickly! (were you hovering? LOL) Melissa

I was using pour through method to catch about 50ml leache. I keep flushing my pot for about 10 times, finally the EC value drops to about 500us/CM. That keeps me thinking that after making the fresh soil mix, maybe we should flush the mix really well with clean water until the EC value drops to a reasonable range. There is a possibility that for slight acid mix like mine, once you add lime or gypsum or even bone meal, there is a reaction to release the Ca+ ion. If you don't flush the mix well with water, the EC value going to be very high initially. The value is only going down after about 10 deep watering. Unfortunately most of the time when we transplant, we just water once until the water runs out from the drain, the shocked plant will stay in high EC value soil medium, the water intake is restricted, we water less often, the poor plant will stay in such soil for a very long time. That may explains that why so many new transplants get stunned growth for such a long time. I am also thinking that the micro-nutrients and all other organic supplements should be mixed after the flush. Thanks Tao