Plum and greengage trees have the same pollination necessities as described for apple tree pollination, though things are made slightly easier by the fact that there are more self-fertile varieties. If you plant a self-fertile plum, it will produce fruit without a pollination partner. If you plant a partially self-fertile plum, it will produce some fruit most years, but it will be more successful with a pollinator. If it is self-sterile, it definitely needs a pollinator to set a crop.
Plums, greengages and damsons are all Prunus domestica trees, and therefore they can all cross-fertilize, as long as they are compatible in terms of flowering time. You can use the table below to determine pollination compatibility.
Plum, greengage and damson varieties are subdivided into five groups, A, B, C, D, E, according to their flowering time. A tree will cross-pollinate with trees in its own group, and the groups on either side. For example, for a tree in group C, a pollinator can be in groups B, C or D. Things are made easier by the fact that most plums, greengages and damsons are in groups B and C.
Plum, gage & damson pollination chart
|Belle de Louvain||Plum||Dessert||Partially self-fertile||C|
|Coe’s Golden Drop||Greengage||Dessert||Self-sterile||B|
|Early Laxton||Plum||Dessert||Partially self-fertile||C|
|Early Transparent Gage||Greengage||Dessert||Self-fertile||C|
|Marjorie’s Seedling||Plum||Dual-purpose||Partially self-fertile||E|
|Mirabelle de Nancy||Plum||Dual-purpose||Self-fertile||C|
|Old Green Gage||Greengage||Dessert||Self-sterile||D|
|Oullins Golden Gage||Greengage||Dual-purpose||Self-fertile||D|
|Rivers Early Prolific||Plum||Cooking||Self-fertile||B|