Is Opal plum self-fertile or self-sterile?

Opal European Plum is a self-fertile cultivar. It sets a crop with its own pollen and does not strictly require companion pollinizers, though interplanting with overlapping bloom cultivars can enhance fruit set and yield stability.

Can Opal act as a pollen donor for other plums?

Yes. Opal European Plum produces viable, fertile pollen that readily cross-pollinates other compatible plum varieties flowering across its bloom window.

Which bloom group does Opal plum belong to?

Opal European Plum flowers in Bloom Group 3 (Mid-Spring). It reliably cross-pollinates with compatible cultivars in its own group or immediately adjacent groups (±1 bloom group).

Which plum pollination pool does Opal belong to?

Opal European Plum belongs to Pool A (European plum, gage and damson). A compatible pollen partner must flower in the same or an adjacent bloom group and belong to the same pool. European and Japanese plum pools do not cross-pollinate.

Curated Pomology Guide · Bloom Group 3

Opal European Plum
Pollination & Compatibility Guide

Opal plum pollination guide: self-fertile Pool A status, Group 3 bloom, Victoria partnership and dessert-fruit management.

Pomological Verdict & Botanical Profile

Opal is Self-Fertile (Pool A)

Sets Alone · Same-Pool Partners Only

Dessert plum, self-fertile. Partners: Victoria, Czar, Denniston's Superb.

Pollination Pool / Ploidy: Pool A · Hexaploid (functional diploid)
Required Companions: 0 (Self-Fertile)
Bloom Group: Group 3 (Mid-Spring)
Harvest Timing: Early Season

Primary Uses:Fresh Eating

General Notes: Heavy cropper

Flowering Period & Overlap Window

Plum bloom groups run from 1 to 5. A useful partner flowers in the same or adjacent group and belongs to the same pollination pool. European plums, gages and damsons are Pool A; Japanese plums and prairie hybrids are Pool B. A tree from one pool cannot pollinate the other.

Flowering Overlap Range for Opal

Early Overlap

Group 2

Opal

Group 3

Late Overlap

Group 4

For Opal, select a compatible plum in the same pollination pool flowering from Group 2 to 4; bloom overlap alone does not bridge Pool A and Pool B.

Compatible Pollination Partners (9)

Test in Checker

Cultivar	Bloom Group	Overlap Type	Harvest	Primary Uses	Interactive Test
Victoria (European)Guide	Group 3	Full Overlap	Mid-Late	Fresh Eating, Canning, Jam	Test Cross
Blue DamsonGuide	Group 3	Full Overlap	Mid-Late	Cooking, Preserves	Test Cross
French Prune (Agen)Guide	Group 3	Full Overlap	Late	Drying (Prune), Cooking	Test Cross
Italian Prune (Fellenberg)Guide	Group 3	Full Overlap	Late	Prune, Drying, Canning	Test Cross
Stanley (European)Guide	Group 3	Full Overlap	Mid-Late	Prune, Fresh Eating, Canning	Test Cross
Cambridge GageGuide	Group 4	Full Overlap	Mid	Fresh Eating	Test Cross
President (European)Guide	Group 4	Full Overlap	Late	Fresh Eating, Storage	Test Cross
Damson (Shropshire)Guide	Group 4	Full Overlap	Late	Cooking, Jam, Jelly	Test Cross
Mirabelle de Nancy (European)Guide	Group 4	Full Overlap	Mid	Fresh Eating, Brandy (Eau de Vie)	Test Cross

Incompatible Varieties & Exclusions (5)

These cultivars cannot serve as pollinizers for Opal because of a different plum pollination pool, a documented incompatibility or another exclusion in the source data.

Green Gage (Reine Claude)Guide

plum incompatibility groups are only partly mapped, so only cultivars documented as reliable donors are offered. Green Gage (Reine Claude) is not one of them — that is a gap in the data, not evidence it is incompatible.

Imperial Epineuse (Prune)

plum incompatibility groups are only partly mapped, so only cultivars documented as reliable donors are offered. Imperial Epineuse (Prune) is not one of them — that is a gap in the data, not evidence it is incompatible.

Jefferson (European)Guide

plum incompatibility groups are only partly mapped, so only cultivars documented as reliable donors are offered. Jefferson (European) is not one of them — that is a gap in the data, not evidence it is incompatible.

Moyer Supreme (Prune)

plum incompatibility groups are only partly mapped, so only cultivars documented as reliable donors are offered. Moyer Supreme (Prune) is not one of them — that is a gap in the data, not evidence it is incompatible.

Yellow Egg Plum (European)

plum incompatibility groups are only partly mapped, so only cultivars documented as reliable donors are offered. Yellow Egg Plum (European) is not one of them — that is a gap in the data, not evidence it is incompatible.

Grower Commentary: Opal in an Early Dessert Block

Opal is a self-fertile Pool A dessert plum flowering in Group 3. It does not require a second tree to carry fruit, yet Victoria or another European plum in the same bloom window can support set when flowering weather is uneven. Keep the pool boundary explicit: Methley and other Japanese plums may flower early, but they are Pool B and are not useful pollen partners for Opal.

The cultivar's dessert use places a premium on fruit size and clean skin. Watch set soon after petal fall, because a crowded crop can produce uneven grades and put weight on young laterals. Thin early enough for the remaining fruit to size, then keep a steady water supply through enlargement. The aim is a regular picking crop, not the highest possible number of fruitlets.

Opal can fit a smaller bush block on St Julien A or Wavit, provided the row leaves room for a spreading plum canopy and hand picking. A sheltered position helps bees work during its early-to-mid bloom, but shelter must not trap cold air. Where spring frost repeatedly settles, moving the planting upslope matters more than adding another pollen donor.