Plum, A.U. Rosa, Bare Root

A.U. Rosa Plum (Prunus salicina ‘AU-Rosa’)

A.U. Rosa is a Japanese-type plum developed through Auburn’s breeding program. Its red-skinned fruit and yellow flesh are useful fresh and in preserves, with disease tolerance among the reasons to consider it.

Key Characteristics

Sweet fruit with a yellow interior

The red-skinned plums develop good sweetness as they ripen. Use them fresh, cooked into preserves, or baked into a summer dessert.

Breeding aimed at a practical orchard

AU-Rosa was developed for useful tolerance to problems that affect Southern plums. Keep ordinary brown-rot and insect care in place rather than treating that breeding background as immunity.

A partner makes the planting more dependable

Some sources rate A.U. Rosa as self-fruitful, while trials have not always agreed. Plant a compatible Japanese-type plum such as Shiro to improve the chance of a useful crop.

Pollination Partners

Self-fruitfulness is reported inconsistently, so plan for cross-pollination with Shiro where bloom overlaps. Another A.U. Rosa on a different rootstock remains the same cultivar. Cross-pollination depends on overlapping bloom, not matching harvest months.

Rootstock and Mature Size

The standard Halford option can grow roughly 15–20 feet with orchard pruning. The Mariana 2624 option provides more size control, approximately 12–18 feet; site, training, and cultivar vigor also affect mature size.

Product Details

• Sun: Full sun to light partial shade; full sun is best for fruiting.
• Soil: medium to medium-dry, well-drained soil; avoid standing water.
• Mature height: Approximately 12–20 feet; see rootstock and pruning guidance above.
• Bloom: Early to mid-spring; white flowers.
• Fruit: Red-skinned plums with yellow flesh and sweet-tart flavor.
• Uses: Fresh eating, preserves, jam, baking, and canning.
• Ripening: June–July
• Chill hours: Approximately 700–750 hours.
• Pollination: Cross-pollination recommended for dependable cropping; self-fruitfulness reports vary.
• USDA hardiness: Zones 5–9.

General Plum Orchard Guidance

A good start

Choose well-drained soil and enough room for the mature tree. Water consistently while roots establish, mulch with space around the trunk, and keep vigorous grass and other competitors away from the young root zone.

Fertility and fruit-tree guilds

Use a soil test to guide lime and fertilizer rather than feeding heavily by default. Our Tree Planting Kit fertilizer blend is an optional planting supplement; keep concentrated fertilizer away from bare roots and avoid excess nitrogen.

Interested in permaculture and stacking functions around your fruit trees? Explore our fruit-tree guild guide for ideas on combining plants for flowers, ground cover, and mulch while giving your tree room to grow.

Practical pest and disease care

Thin crowded fruit to improve size and protect branches, prune for airflow in dry weather, and remove fallen or mummified fruit. Monitor for brown rot, plum curculio, and black knot where it occurs. Early sanitation and fruit bags where practical can reduce problems; protect bees during bloom.