Berries not picked when they are ready will be too ripe by the next picking. Pick directly into selling containers. Processing or PYO berries can be placed in deeper containers. Spread uniformly across the row or side dress with half on each side of row in a 3 foot wide band. If using a split application, apply the first portion at bud break and the remainder just after harvest.
Ammonium nitrate is the most common form of N used on blackberries.
The incorporation of P and K should be based on soil test recommendations, see table below. Contact your buyers if you are selling to retail markets and give them a crop estimate and timetable of when fruit will be available. I will be upgrading my web site this summer and would like to include lots of bramble pictures. North Carolina State University Vernon G. James Research and Extension Center 207 Research Station Rd.