For fruitnut (or other): potted blackberry question
I planted 2 triple crown blackberry plants in spring 2012, each in a 14 gallon pot. Together, they produced 1 gallon of delicious, ripe, fresh blackberries. I don't know if that's a lot or a little for first year potted black berries, but we were pleased.
However, each plant has produced only one new cane this year. Surely we won't get many berries next year. Something's wrong.
Let me describe their care and feeding.
- I used an organic potting mix of mostly compost and pine bark fines. I have other fruits growing well in a similar mix.
- In 2012, I selected around 6 canes per plant, and tipped them at about 3'. Weaved them onto a small trellis. As I remember, I thought I tipped them pretty late, but I was waiting for the canes to grow a little first. Those canes (tipped in 2012) didn't produce much lateral growth until this year (2013). But they did grow a mess and produced a lot of berries.
- In 2013, I gave them a balanced slow release fertilizer at bud swell and again late June or early July.
- They generally get watered every day in the summer. In the winter the pots were in an unheated garage, but keep moist.
Any ideas about why these plants only produced one new cane? I'm thinking maybe
1) Not enough nitrogen?
2) Over cropped. Should have selected fewer canes in 2012 for 2013 production?
Any suggestions for better results in the future?