my concern was that the coir/peat/perlite mix may be too clumpy/muddy - i was hoping the perlite would break it up some. i thought of throwing in some humus and compost. thoughts on this? The trick is a mix that is always moist, but also supports good aeration. I think that the peat/coir/perlite will probably achieve that, but not for more than a season as they will begin decomposing and breaking into smaller sizes quickly. As this occurs the water retentiveness of the mix increases, but at the expense of air holding capacity of the mix. Compost and humus would likely make the problem worse. I don't know what humus is in this sense as the stuff sold in bags isn't what I consider humus, it's often sawdust like stuff from what I have seen, but haven't looked in a few years. Compost will also break down very quickly. What many growers use is pine bark as the basis of the mix. It also breaks down, but more slowly and it starts at an appropriate pH. Filix has reported good success with his blueberries in Al's 5:1:1 mix (5 parts pine bark fines, 1 part peat, 1 part perlite). If you are concerned about the suitability of any mix you can test it in a clear cup. Fill the cup with mix, saturate it with water and then poke a hole in the cup so the water can drain. After no more water is draining, look to see if there is a water layer on the bottom. This would be the perched water table and blueberries aren't going to like it. If you just have an inch or less and you are using a reasonably tall container it's likely not going to be an issue, but if you have much more than that you are taking a risk with the shrubs. Keep in mind the organic component of any mix is going to break down over the season and the PWT will increase in height as it does. Some materials break down quickly, others more slowly. so, justa, i've read many of your responses to BB/soil pH, and i welcome the difference of opinion that you and i seem to share - i find soil pH paramount, you don't seem to, rather you attain it via watering and fertilizers. It isn't that I consider pH unimportant, but rather it's next to impossible to control without continual monitoring. As you saw from the link you posted the pH of the mixes shifted throughout the test. With a quality fertilizer intended for hydro or container use many nutrients will be chelated and available to the plant even when the pH is out of normal bounds. Unless one has testing equipment and is willing/able to respond appropriately to control pH swings (occur quickly and are short lived) and shifts (a longer term movement) it's not really worth fussing over, in my opinion. Rather, by building a mix that starts out with an appropriate pH range, and neutralizing the alkalinity of the irrigation water via vinegar or using rainwater when practical there should never be a problem. Something to keep in mind is that the plants are getting nutrients from the water and whatever nutrients are dissolved in it, not (so much) from the growing media. If the pH of the water/solution around the roots is good, then the plant is happy too ;) BTW, are you a veterinarian? Just wondering due to your handle/name/alias ;)

If you need to use store bought potting soil, look for Azalea mix. It would be hard to grow in regular potting soil. The soli acidifier depends on bacteria, and it's hard to keep bacteria in pots. I do it with compost, and adding the bacteria monthly. But compost is neutral and I use a peat moss compost for blueberries. It is more acidic than most composts. Vinegar works, but you must flush the carbonates out. Vinegar breaks down via bacteria and the carbonates become free. But if you water it heavy you can actually flush the carbonates out. I use battery acid which is perfectly safe to use. Well for the plant, it is always dangerous to work with acid. Many myths surround battery acid. It must be pure acid else your batteries could explode. No lead or other heavy metals are in it. It's 30% Sulfuric acid, and safer than pure sulfuric acid. Sulfuric acid turns carbonates to gypsum which removes them permanently. Gypsum is very stable and neutral. I have Southmoon too, and another 6 cultivars. It's best to have other cultivars as they are somewhat self fertile though they will bear more fruit with pollinators around. Yes, you can add the soil acidifier, I do too. It's hard to keep the PH down, so I use all tools available. You also need to use an acidic fertilizer.

For one plant, buy the mix as suggested. But, peat moss doesn't have enough nitrate to bother (or help) the blueberry. So long as you are talking about the baled Sphagnum moss peat that is commonly sold in the compressed bales, not reed peat in regular bags such as fertilizer or most mulches and soils come in. That peat may or may not be OK for blueberries and it would be hard to tell without trying it. It could have too high of a pH. It also could be as high as 4-5% nitrogen, but not as nitrate.

Don't know about more Miracid, but I just did the calcs for langbeinite for you ... Langbeinite can satisfy two things you need - potassium (K) and magnesium (Mg). Langbeinite is 18.8% K and 11.7% Mg. Your soil tests recommends 140 lbs/ acre Mg and 110 lbs/acre of potash (83%K) which translates to 91 lb/acre of K. For the K: 91 lb K/acre @ 0.188 lbs K/lb langbeinite leads to 485 lbs langbeinite/acre, or for your area ~14 lbs langbeinite For the Mg: 140 lbs Mg/acre @ 0.117 lbs Mg/lb langbeinite leads to 1196 lbs langbeinite/acre, or ~ 34 lbs for your area. If you use langbeinite at the amount needed for Mg, you will be adding about 2.5X as much K as called for. If you wanted to go this route, you might check with the soil lab if that amount added would put you into an excessive situation. In my experience those folks are typically very helpful and welcome calls for guidance based upon a test result. I have a quibble with the amount of Epsom salts they advise based upon their Mg recommendation. If you use the 140 lb/acre Mg needed, that would require 1420 lbs of Epsom salts, not 1270. If you use the 1270 lb rate for Epsom salts (9.86% Mg), you would be adding 125 lbs of Mg, not 140. In the above I used the 140 lb/are rate. In the end, I doubt it makes a lot of difference, but their conversion isn't consistent with the need they state. This post was edited by TXEB on Thu, May 23, 13 at 10:40