HELP! My potted soft fruit plants are dying!

[Tyranna 10]

Sorry about this but it is a bit of an emergency; I have tried everything to rectify it but nothing seems to be working.

 

While it has also happened previously with other potted fruit plants, at present I have two: One blueberry in 6" of compost in a 10" dia pot and one Tayberry (A variety of raspberry) in 7" compost in a 10" dia pot also.

 

Both plants are in pots on a South-Facing balcony with a good amount of sunlight for approximately 8 hours a day (when its not cloudy lol)

 

In the case of the blueberry, I have had 3 attempts now; the current one remains leafless with no signs of budding although the stems are still a healthy green, and I keep it under suitable acid soil conditions (Unlike the previous two I water it ONLY with rainwater) and I keep the soil very moist as blueberries are a bogland loving plant.

 

The Tayberry was bought with a cut-off woody stem of about 4 inches above ground, but also had several young green leaves sprouting from about 2" up and these leaves stayed green and healthy for more than a month, but instead of growing in size and sending off more leaves and shoots, they have stayed small and stunted, and finally in the last week they have turned brown and started dying, with only one group of leaves still green, so the plant is URGENTLY needing some kind of remedial action. Again, it is potted in standard 'Multi Purpose Compost' with 'added John Innes' (It is composed mainly of wood/bark/peat material) and in the case of this plant I have watered it with a mixture of tapwater and bottled rainwater.

In addition with both plants I have fed them with a sprinkling of plant food pellets suitable for shrubs (I have followed the instructions re. amount of feed per unit of soil).

Very recently also some of the other plants on my balcony have had greenfly, but this certainly isn't the problem with the two soft fruit plants, so issues like pests, or fungi, do not seem to be the cause.

 

Finally, as both plants have only been in their pots for a month or two, the issue of roots outgrowing the pot is clearly not the cause of their dying either. I have had other plants in pots where the roots have 'balled' tightly and after repotting or planting out on the allotment they flourish happily. My allotment is on a west-facing well drained slope with stony loam soil and is shaded from the south so it gets probably only around 8 hours of direct sunlight a day.

 

Any help or advice as to rescuing these plants and planting them on my allotment to ensure their survival would be most welcome.

 

---------- Post added 22-06-2016 at 18:33 ----------

 

Shame there's no reply yet, but I examined my Tayberry plant and its roots are definitely not very extensive so it cannot be roots crowding the pot. I have kept watering it, but it is still slowly turning brown; again I am NOT over-watering it.

 

Any help would be really REALLY appreciated!

Edited June 21, 2016 by Tyranna
spelling corrections

[punkin 10]

Its hard to tell without inspecting the plants but they could have root rot or the pot could contain diseases or bugs, if possible plant out in the garden to help them to recover then try potting with fresh compost just before winter time

[gnomi 10]

The blueberry needs extremely acidic compost to survive and will die in 'normal' compost. You would usually have two together as well, to aid pollination. Mine are in a big planter with my own compost and are thriving. It may be the same for the tayberry, mine is in the ground so not 100% sure.

[Chez2 10]

The soil could be getting too warm with the pots being so small. Only a suggestion, could be many reasons.