Coco Coir usually has a high pH, so I wonder why it was suggested to use it for blueberries?

Josh

If the pH is too high, you'd expect to see pale, chlorotic leaves (yellowing with green veins). If the leaves are a nice healthy green, then the pH is probably low enough for the time being. That being said, I agree with Josh about the coir. It might be fine as a small part of the mix, but 40% seems a bit much given its high pH. When it's time to repot and replace the potting mix, I'd suggest using aged pine bark fines in place of all of the coir and perhaps a portion of the peat, as well. As for why your plants aren't growing at this point, it's hard to say, but one possibility is that the Holly Tone isn't providing enough nitrogen. You won't do any harm by adding a soluble fertilizer at 1/4 strength at each watering, and that might help. I really like Jack's Classic Acid Special, but MirAcid is also a good choice. If you've haven't already, you should also test the pH of your irrigation water. If necessary, and it probably will be, add an acid (like vinegar) to lower the pH to somewhere in the 5 to 5.5 range.

At an average of 4.5 or so, the pH of peat is ideal for blueberries, so, no, the coir and peat don't balance each other out. Rather, the mix of the two is likely to have a pH that's on the edge of what's tolerable for blueberries (5.5 at the upper end), and the addition of tap water, which usually has dissolved bicarbonates in varying quantities, will likely push the pH too high over time.

Ok, I'm going to plan on re-potting them into a better mix next season. For now I'm just going to see how these do with some extra nutrients and water pH adjustments. My kumquat tree has responded well to adding vinegar, will see if I have the same success with these guys.

Would foliage pro 9-3-6 be of any help?

No, don't use Foliage Pro. You want a fertilizer with the majority of its nitrogen in the form of ammonium or urea, not nitrates (as is the case with Foliage Pro). That's why I recommended Jack's Classic Acid Special (mostly ammonium) and MirAcid (mostly urea).

Ok, i'll check those out. Thanks

Make sure the mix hasn't gone hydrophobic. Mixes high in peat are notorious for this - you pour in water, and it goes right through the pot and doesn't actually wet the medium. Just stick your finger into the soil and you can tell immediately.

If that turns out to be the problem, sit the pots in a container of acidified water or rainwater for an hour or so, so that they can soak up the liquid from the bottom.

Got my miracid yesterday and applied it. Will see how it does.

Re: Hydrophobic
I have been testing the moisture with a wooden skewer and the mix seems to be fine as far as moisture is concerned.

I did read that blueberries don't like to have the top of the soil dry out at all though, is this true? Should i go ahead and mulch the containers? Any recommendations for type of mulch?

This post was edited by doomahx on Fri, Jun 13, 14 at 5:36

Bark mulch, pine straw, or straw.....

Josh

I wouldn't say the top of the soil cannot dry out at all, but I wouldn't want to let the root zone dry out. Roots generally are shallow as compared to other plants. What they want is and permanent but moderate soil moisture in the root zone. Small pine bark works great for me.

How often should i feed with miracid? As per the instructions on the label?

I see instructions for outdoor and indoor plants but are they assuming outdoor means in the ground and indoor means container? If that's the case then I should be following indoor feeding instructions for my outdoor container plants I assume?

I would go with outdoor instructions....because the outdoor plants (even though they're in containers) are receiving so much more light and are doing so much more building with those nutrients than the houseplants indoors.

If it seems like too much, find a happy average in the middle.

Josh

Looks like the miracid did the trick. Yesterday i noticed tons of new shoots growing. Thanks!

Looks like the miracid did the trick. Yesterday i noticed tons of new shoots growing. Thanks!

Just wanted to post an update. My bushes seem to be thriving now that i've started adding miracid. I've also started spraying the top of the soil more often to keep the top roots moist while doing a deep watering once a week.

Check out all of that vibrant new growth!

This post was edited by doomahx on Thu, Jul 31, 14 at 7:05

How did they look now? ;)

Growth was great all summer last year, the plant even started producing flowers in september/october before going into dormancy. Not much going on with these yet this year though. Starting to get a bit worried but not sure if it's just because we had a very long winter.

So far, I have absolutely zero growth even though both bushes seem to be alive. Both have plenty of green stems and wood that's alive. Hopefully it will start soon :(