Stopping Fruit on a 'Fruitless' Purple Plum

Why a 'Fruitless' Tree Fruits

Many "fruitless" purple-leaf plums (Prunus cerasifera cultivars) are selected for low fruit set, but they are not sterile. Environmental conditions, pollinator activity, and tree age can trigger unexpected fruiting.

Chemical Fruit Suppression

The product Florel® (ethephon) breaks down to ethylene, a plant hormone that aborts flowers and prevents fruit formation. Key points:

• Apply at early bloom (when 10–20% of flowers are open).
• Thorough coverage of the entire canopy is essential—difficult on larger trees.
• Follow label rates exactly; overdosing can cause leaf scorch or premature leaf drop.
• Reapplication may be needed annually.

Non-Chemical Options

Hand-thinning flowers is impractical. Accepting the fruit (which is small and not very messy) or replacing the tree with a truly sterile ornamental (e.g., Prunus 'Krauter Vesuvius', which rarely sets fruit) are alternatives.