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Plum & Prune Trees Care Guide

PRUNE: When completely dormant in December or January. European varieties need only a light pruning and thinning. Japanese varieties should have one-quarter to one-half of current season’s growth removed. To identify fruiting wood, see our Fruit Tree Pruning Information Sheet. Prune again in late June or early July. Remove the strong, vigorous shoots from the interior of the canopy to improve light penetration and air circulation.

SPRAY: Dormant spray in December or January after pruning with Master Nursery Pest-Fighter Year-Round Spray Oil and Microcop. Follow label directions for appropriate quantities. Always check with your nursery professional to properly diagnose problems before undertaking additional sprays.

SHOT HOLE:

• Spray: Spray trees again with Microcop at pink bud and again at full bloom stage.

• Pruning: Prune to allow good ventilation.

• Sanitation: Remove and destroy affected buds and blossoms during bloom. Remove and

destroy maturing fruit when symptoms appear. In August or September, remove and

destroy mummies and fallen fruit. Do not compost.

• Irrigation Methods: Use basin or drip irrigation to avoid wetting blossoms, foliage and fruit.

APHIDS:

• Spray: Watch for aphids when new leaves are one-half to one inch long. Spray with Malathion or Sevin. Less toxic sprays include Master Nursery Nature’s Pest Fighter and Safer Yard Insecticide. Use Master Nursery Pest-Fighter Year-Round Oil as a dormant spray only, as described above under ‘SPRAY.’

• Beneficial Insects: Set out Ladybugs, Lacewings or Praying Manti through the summer. Best when yard has nectar-producing flowers which attract adults to stay in area. Soldier beetles will appear naturally to feed on aphids.

FERTILIZE: Use Master Nursery Fruit Tree & Vine Food twice a year, around Memorial Day and Labor Day. If you prefer organic fertilizers, use Dr. Earth Fruit Tree Fertilizer two to three weeks earlier. Water in immediately after application.

WATER: At planting, construct a soil basin at the dripline of the tree. As the tree matures, extend the basin to the span of the dripline. Flood weekly during the first year and then at 2 to 4 week intervals when the tree is mature. If a drip system is used, place hosing along the tree’s dripline with emitters on 18 inch centers. This system will also need to be adjusted as the dripline expands. Both flood and drip irrigation are preferable to sprinklers, since they reduce water splash, a common byway of fungal spores. If sprinklers must be used, adjust heads so that they angle water low and away from the trunk. Keep in mind that a large, mature tree may consume up to 200 gallons of water per week in July and August.

FRUIT THINNING: When fruit reaches about one-half to three-quarters of an inch in diameter, thin to about 4 to 6 inches apart. OTHER COMMENTS: Many plums are not self-fruitful and require a pollenizer to ensure good crops. Check with one of Wegman’s staff to determine your needs. Oozing, amber-colored gum on twigs and tree trunks may indicate the presence of borers or fungus. Bring several leaf and twig samples to Wegman’s Nursery for evaluation whenever these or other symptoms appear.

To prevent sunburn injury and to reduce borer infestations, paint trunks and lower branches of young trees with a one to one mixture of white interior latex paint and water. Apply the paint mixture from 2 inches below the soil surface to three feet above.

Adapted from Ogawa and English (1991), Diseases of Temperate Zone Tree Fruit & Nut Crops, UC Extension

Publication 3345 and Flint (1998), Pests of the Garden and Small Farm, 2nd Ed., UC Extension Publication 3332.

© 2005 Wegman’s Nursery