Almost NO blueberries this year
I have an established blueberry patch (6 bushes). They have been productive for several years - the oldest bush is probably 10 years old, youngest is maybe 5. I generally get about 20-25 quarts of blueberries. I try to keep them mulched with pine bark mulch, and fertilized (but not a lot) and water if needed in the spring. Once or twice over the years I have pruned out about 1/3 of the older limbs (but not this year). Early this spring, I noticed there were not many blossoms, although the bushes looked healthy. This of course meant not many berries. I did not even bother to cover - let the birds have the few berries that were there. Any idea why I had so few blossoms/berries this year? Was there something about this past winter that would have caused it?
Hi- there could be many causes for the low productivity this year, acting singly or in combination:
1. Flower buds develop from mid-summer through fall. Any significant plant stressors during that time (drought, extreme heat, waterlogged soil) could have interfered with flower bud formation. We were getting copious amounts of rain during that time in 2018.
2. It's possible that dormant flower buds began to lose some of their cold temperature protection during a string of days in the upper 40s or 50s. Those buds could have then been damaged by a return to cold temperatures.
3. Too many old canes. With healthy plants that are 5-10 years old you should be removing the oldest canes (shaggy bark and reduced fruiting) each year (renewal pruning) to force the crown to produce new shoots.
4. Deer are fond of tender blueberry shoots?
Prune out the oldest thickest canes (7 years old and up) when plants go dormant this fall. Keep plants well-watered through dry periods between now and late fall when rainfall is lacking. Fertilize at bloom and then 2 weeks later with ammonium sulfate.
Blueberry web page: https://extension.umd.edu/hgic/topics/blueberries