Managing Peach Blocks When You Have No Crop
This has proven to be a difficult season in the Northeast weather-wise, especially for peaches. First, there was what we’re calling the Valentine’s Day Massacre on Feb. 14, where temperatures reached -16°F in the Hudson Valley at some locations, -8°F in northern New Jersey. Similar low temperatures in Massachusetts and Connecticut were observed.
When temperatures hit below -10°F, most peach buds are gone; it is -8°F for many of the white flesh peach varieties from California. The lows in New York and New England took out virtually every peach bud on Feb. 14.
Then early warm temperatures hastened bloom in peaches in New Jersey, Pennsylvania, and Virginia. These temperatures moved apple development along as well.
Extreme cold on March 21 and 22 and then again April 4-6 hurt peaches in Northern New Jersey, Pennsylvania, and south to Virginia. Some blocks (varieties) are completely gone, others have some crop to a partial crop. It is variety by variety, site by site.
Here are some tips to manage peach blocks that have 100% crop loss.
Prune hard and well. This is the time to do any corrective pruning to get trees down to their optimal height and shape. Do the fine pruning to eliminate the small shoots that would not have been able to support a good peach this season. The focus of your pruning is to let adequate sunlight into the canopy to form good pencil-size fruit shoots this season for next year and to form strong fruit buds on these same shoots this fall.
On an open center vase peach tree, 125 pencil-size fruit shoots are optimal. Shaded shoots will be weak and not be productive next year. Make sure to remove any and all dead or diseased wood, no matter how small. Dead wood allows disease to enter the scaffolds and trunk.
This would be the season to definitely summer prune in mid-June to July to keep adequate sunlight into the trees to keep fruiting wood healthy.
Cut Your Nitrogen
You need to reduce your nitrogen fertilization by 50%. My goal is to have 50% of my nitrogen applied as a complete fertilizer, based on soil and leaf tests, three weeks prior to anticipated bloom date. The second half of the nitrogen is applied (as nitrogen only) after shuck split once you know you have a crop, on fruiting blocks. No more additional nitrogen should be applied on non-fruiting peach blocks.