Repotting a Sunshine Blueberry
Pulled the last of the blueberries off my Sunshine Blue plant last week. Its been in a 15 gallon pot for 3 years now and was my first potted blueberry. The potting mixed was about 80%peat moss and 20% pine bark. I had noticed that some of the older canes didnt leaf out very well this year and the fruit on these canes was sour and tasteless. That being said, the canes were still expanding and pealing bark. Usually they become unproductive when they turn grey and quit expanding. Concidering the mix was mostly peat I had to pull and examine thinking it was maybe a soil issue.
Few things I noticed here. I couldnt really define a perched water table in the soil. The bottom 3 inches of the soil was moist as expected but not saturated. Bark was still intact and had not broken down much at all. During the root prunning I even noticed flakes of soil sulfer still intact from the origional potting. Hard to believe it hadnt broke down yet? The roots had completely filled the pot and still was pushing fine white feeder roots. I prunned 3 to 4 inches off the sides of the root ball and 1/3 to 1/2 off the bottom. Went back with a mostly bark with some peat and perilite for repot.
In conclusion Im not 100% I should have even repotted yet. I did it more as a guage to give me some kind of time line for the rest of my potted plants. I believe I could have just cut back the unproductive canes and waited at least another year or two before root prunning. After the repotting process I cut the top back very hard leaving only 5 young canes and cut back the older ones 4 inches from the soil. Hopefully all is well. Only time will tell!