I read mixed content about PK. Some say it's sterile. Others say it produces bird fruit. It's a selection of P. nigra, which is often recommended as a pollenator for plums. Would PK work for this? Part of this depends on the nature of PK. Double flowering cultivars often have double chromosome numbers, which makes pollenation difficult (But see birch...) Some sparse fruiting cultivars have no or little pollen, or inaccessible stigma. What's the scoop?
