Q...since BB's love acidic soil...I use water soluable camelia fertilizer by Miracle Gro. In diluted amounts...you can apply every couple of weeks or so, and there is no danger of burn. From what I read...do not pick berries until totally blue for a few days...they sweeten up. Read info at: Dave Wilson Nursery. gl

I use the same Miracle Gro product (MirAcid), and I've been very happy with the results. While I occasionally supplement with a liquid fish product, I wouldn't advise relying on it alone, nor would I use a citrus fertilizer (it might be fine, but blueberries have specialized requirements that citrus doesn't share).

I've linked to a Spectrum Analytic's Fertilizing Blueberries publication. While it's focused on growing blueberries in the ground (instead of containers), it has a lot of useful information. Here's one particularly relevant section:

"Blueberries...have somewhat unique N requirements. They are not able to use nitrate forms of N (NO3-N) effectively. These plants have evolved in soil conditions that do not naturally contain a significant amount of NO3-N and they depend more on ammonium-N (NH4-N). Blueberries take up both forms of N, but they have limited nitrate reductase activity. Nitrate reductase is an enzyme that is needed to convert nitrate to amino acids and proteins. The limited nitrate reductase system in blueberries means that they cannot efficiently utilize nitrate forms of N. Some reports also state that excessive nitrate fertilization can lead to leaf burn. Two recommended N sources include ammonium sulfate and urea, which either contain or form ammonium-N after application."

Here is a link that might be useful: Spectrum Analytic: Fertilizing Blueberries

As to your first question, picking blueberries at their peak is a bit of an art (one I've yet to master). Different varieties will mature somewhat differently -- some are tasty as soon as they turn blue, and others need a bit more time. Really, the only thing to do is experiment with your own particular plants -- try a few as soon as they turn, and if they're not good and sweet yet, give them a day or two and try again.

EDIT: Looking back, I see that I didn't quite answer the question that you actually asked (how long to ripen). That varies by cultivar (and the month in which they ripen will depend on your geographic location). Did you buy these plants at Home Depot? That's the only place that I've encountered Home Bell (a rabbiteye variety, I think), and I don't know if it's an early, mid, or late season ripener. Do you know the variety name of your second bush, or did they merely label it as "rabbiteye"?

This post was edited by shazaam on Sun, Apr 21, 13 at 22:06

I have 1 Jersey and 2 northern highbush, have been using the Miracid along with blood meal. Shazaam, is blood meal an acceptable form of nitrogen for them? Sorry to hijack this thread!

I'm not an expert and have no experience with blood meal, but I have seen it recommended for blueberries (as well as cottonseed meal, which I do use). Both break down to ammonia and so have an acidifying effect on soil (or so my reading tells me). That being said, blood meal breaks down quickly and can burn tender plants if applied in excess, so I'd be careful not to overdo it.

Thank you everyone for such quick replies!

fireduck- Ill look for that fertilizer tomorrow at work.

shazaam- oh! I didn't know you could use the fish fertilizer AND another fertilizer! Here I was scared to burn my plants. I wonder if that means I can give my roses rose specific fertilizer along with the fish stuff, hmm...
And thank you for answering the question about how long. I actually bought these at my work, Lowes. I believe it was only listed as Rabbit Eye(here we go, i've pulled the tag from the pot) It has Arandano Rabbiteye under the common name.

czimm-no worries about hijacking, we both learn this way ^^

*joking* Ammonia? Blueberries need that? Well, i'll just get my kitties to turn the pot into their litterbox!

"Arandano" is the Spanish word for "blueberry," so it looks like you have a mystery rabbiteye -- the big box stores have gotten really bad about selling poorly labelled berries. It's more than likely one of the more common rabbiteyte cultivars like Powderblue, Premier, or Tifblue.

As for burning the plants, it's definitely never a good idea to heavily fertilize a blueberry bush -- they have shallow root systems and so can be especially sensitive to root burn. Nonetheless, fish fertilizer is typically quite weak, so it would take a lot to burn your plant. I find that my blueberries are happy with a frequent low fertilizer dose -- I typically use MirAcid at 50% to 60% strength at every watering (that's about 1/4 tsp per gallon of water). I don't use liquid fish regularly, but I do use it as a supplement once in a while (along with liquid kelp).

*MirAcid doesn't supply sulfur, magnesium, or calcium, so I incorporate gypsum at the time of planting and supplement with a little bit of epsom salt at each watering.