Earlier this year I bought a small blueberry bush at a local garden store. Since it was written on the attached note that it can grow in a pot on the balcony without a problem, I bought bigger pot, some recommended soil (I used 'rhododendron soil' with a pH value of 4.6) for it and planted it there. At the time that I bought it in late spring/early summer, it had a surprising amount of branches and berries on it, considering it's size.
Things went well for two months or so, I kept it in a half-sunny spot on my balcony (I live in southern Germany) and watered it carefully with tap water, since I was worried about drowning it. Every two weeks or so I fertilized it with a bit of the general purpose fertilizer I use for all my balcony plants (7% nitrate,3% phosphate,6% potassium oxide, smaller concentrations of other stuff). At some point after these two months I noticed that its leaves had started to get brown, dry spots. I assumed the heatwave at the time to be the cause, so I moved it to a more shady place and watched it's moisture level more carefully. Nonetheless, more and more leaves turned brown and eventually were thrown off.
Since I assumed that lack of water could not be the cause, I was worried about having overwatered it after all, so I took it out of the pot and had a look at the soil and it's roots. While the soil was moist, it didn't seem an alarming extend to me and the roots were alive and firm, large enough in number and with still some space left in the pot for them to expand.
A friend of mine that I often talk about gardening stuff with suggested that the bush simply had too many berries to maintain them all, leading to this situation.
Over the course of the last week all the berries and leaves dried up, I removed them since these seemed a hopeless cause to me.
The stem of the bush still looks green and lively, and cutting one of the outlying branches showed that despite a dry outside, the inside is still firmly green and juicy.
Is there hope for this bush to survive and eventually grow new leaves?
What can I do to help it?
Water pH-value: 7.73
Water hardness: 15.6 dH, 2.79 mmol/l