If your blueberry shrub has deep green leaves, and it looks healthy, then soil conditions should be OK. The health of the shrub is the ultimate test. I grow blueberries here in Madison, Wisconsin. It happens that our city water supply, which is well water, contains considerable dissolved limestone. In other words, we have hard water. When I water our shrubs, usually necessary during August, the pH rises, and the leaves grow pale. Eventually, they will turn yellow. So, I add vinegar, 5% concentration, from the grocery store, to our tap water, to lower the pH, and in a month or two, the blueberry shrub leaves turn green again. I also test for pH, and pH testing indicates that when soil pH is above 6.5, the leaves turn yellow. I don't know if its appropriate for you to be adding vinegar to the water you use on your blueberries. It depends on soil pH, and also, on your water supply. You might have hard water, or you might not.

My water has a ph of around 7 or 7.5 and same for my soil. I was hoping to use vinegar to bring down the ph. Also I was hoping that the azalea mix will help for a while with a lower ph level so my new bush can settle better. Like I said, I just used the azalea mix for the first time this week, my older bushes are in normal potting soil and seem to be doing ok to good, they have little leaves but lots of flowers. I bought them last spring, so I'm not sure yet if this is how they are suppose to look around this time of year. Back to the vinegar, how much and how often? (I wonder if azalea soil and vinegar will turn my hydrangeas blue?)
Also does anyone grow Sharpblue? I'm thinking about picking up one of those since I heard that they are a fast growing bush. Thanks!

Based on pH testing, I have to add 6 fluid ounces of vinegar to every 4 gallons of tap water, for use on blueberry shrubs. The vinegar is regular "grocery store" issue, labeled "5% acidity". How often? From what I have read, container gardeners recommend a thorough watering, to flush out excess salts that can accumulate in the soil. There should be some discharge from the bottom of the pot every time you water. It is better to water at longer intervals, and water heavily, than it is to add a little water every day. That said, blueberry shrubs will be permanently damaged if they are allowed to dry out.

Brian:

Azaleas and rhododendrons have soil preferences similar to blueberries, so no problem there. But I noticed you have planted in a clay pot, which I take to mean standard terra cotta.

Clay pots transpire readily, losing a good deal more soil moisture out the sides than other materials like plastics and fiberglass. If you want to reduce the frequency of watering and the consequent accumulation of salts, you might be better off with a less permeable material for your pots.

Don Yellman, Great Falls, VA

Thanks Eric, thats good advice and what I was looking for.

Don: Thanks for assuring me on the azalea soil, I had assumed exactly what you just said and planted the bushes in there. I just bought 2 more bushes yesterday and will plant just the same way. As for the clay pot, I was told not to use plastic containers because the temperature in the soil and of the roots fluctuates more than what is good and can burn the roots in our climate's summer temps. What do you think of using stone containers in the future?, even though they are way more expensive.

First of all, I'm not a BB expert but I've researched asked many questions on this forum and elsewhere. I have approx. 20 BB plants in containers. Take my advice at whatever it might be worth to you.

If you are set on using Azalea soil, consider reading the Dave Wilson Blueberries article (search those 3 terms). They recommend the azalea mix, small to medium bark, and sphagnum peat moss in a 1:1:1 ratio for hot CA weather like yours & mine. I can't attest to the performance (yet) but that basic recipe is sound for holding water and giving a nice low starting pH needed for BB. They also suggest adding CHC (aka COIR in "cube" form) for added water retention. I have several containers in that mix (no chc tho), along with a completely different medium of micro bark and Turface (5:2 ratio). There are pro's/con's of every type mix, so I'll merely suggest that in the Azalea (and any peat based mix) you probably understand you'll need to fully replace the soil in time (years) as it will collapse and the plants will decline for no apparent reason -- some say they go many years in the 1:1:1 DW mix above and they are happy.

You should be able to add 1 tbsp/gal of white vinegar to your water at every watering. Finding the "ideal" amount and frequency requires a lot more work to measure media pH which is difficult to do with accuracy anyway (whereas simple water pH strips are fairly good). Adding pH "reducer" products like sulfur are not consistently effective in containers since they require soil micro-organisms to work; when or if they are working is questionable. Adding the vinegar should be fine to reduce the rate at which your medium pH will rise (as it will naturally do over time).

Terracota is excellent for container plants (if you can afford them). But *might* be inadvisable for BB for the reason Don stated above. They keep the roots cooler as you've learned, but in doing so allows the soil to dry out faster. If you are committed to watering everyday (or however often it needs it), the TC pots are the way to go even for BB. However, it's safer to use white (or stone colored) plastic containers and shade the container itself from afternoon sun. If you do choose TC you should probably consider adding the CHC as the DW article suggests, to help offset the faster drying (though I myself have had a terrible experience with COIR).

Hope this helps.

I am new to growing blueberries myself, but I have read Azaela mix is the best type of potting mix to use.

P.S. Just so you know, I have read Sunshine Blue is able to tolerate higher ph soils that other blueberry plants. In fact, I am thinking of planting my sunshine blue in the ground for this reason.

Cebury: Thank you for the great advice. I have already planted my blueberry bushes in the azaela mix & will leave them be; but for any new bushes I get in the future, I will for sure use the soil mixture. And for the vinegar, I am going to start using it right away! Great info again, thanks!

Container blueberry:Thanks as well, I have read this on sunshine blue as well and that is why I did buy one. I just didn't buy as many since their taste isn't as sweet as my other bushes.