Curling Leaves on Plum Trees: Identifying and Managing Leaf Curl Plum Aphids

As a home gardener and orchardist, I’ve dealt with my fair share of pest and disease issues affecting stone fruits like plums. One of the most common problems plaguing plum trees is curled, distorted foliage emerging in spring. Unlike the fungal disease peach leaf curl, the culprit behind curled plum leaves is actually an insect pest – the aptly named leaf curl plum aphid.

In this article, we’ll take a deep dive into identifying and managing leaf curl plum aphids. Read on to learn:

• What causes curled leaves on plum trees
• How to identify leaf curl plum aphid infestations
• Effective treatment methods
• Preventative care for long-term plum tree health

Arm yourself with information to recognize, control, and prevent plum leaf curl. Then you can get your trees back to producing perfect unblemished foliage and fruit.

What Causes Curled Leaves on Plum Trees?

If new leaves on your plum tree emerge in spring looking tight, distorted, and curled under, the problem is likely due to leaf curl plum aphids rather than a disease like peach leaf curl. Plum leaf curl is caused by the aptly named leaf curl plum aphid (Brachycaudus helichrysi).

These tiny, sap-sucking insects feast on the tender new growth of plum trees in spring. Their feeding causes the characteristic curling, crumpling, and twisting of foliage. Leaves continue to grow and curl around the aphids, forming a protected space where they feed and reproduce rapidly.

An aphid infestation can seriously stunt plum tree growth. It may also reduce the tree’s vigor yield, and fruit quality if left unchecked. Severe infestations year after year can even kill young trees.

So how do you know for sure your tree is under siege by leaf curl plum aphids? Check for these signs:

• Tightly curled, twisted leaves on new shoots
• Deformed, wrinkled leaves that fail to flatten out
• Clusters of aphids on crumpled foliage and tips of new growth
• Stunted, misshapen shoots with reduced vigor
• Honeydew secretions on leaves attracting ants and sooty mold

Carefully unfold the underside of curled leaves to reveal colonies of plump, soft-bodied aphids ranging in color from green to yellowish-brown. If present, take steps right away to control infestations before lasting damage occurs.

Managing Leaf Curl Plum Aphids

Getting an aphid infestation under control requires persistence. Their rapid reproduction allows populations to quickly rebound once disrupted. Follow these management tips to knock back plum leaf curl aphids:

Apply Dormant Oil Sprays

The best opportunity for control is applying horticultural oils during the dormant season. Dormant oil sprays smother overwintering aphid eggs before they hatch and cause damage in spring. Thoroughly coat trees just before buds swell in late winter.

Encourage Natural Predators

Natural predators like ladybugs, lacewings, and syrphid flies help control plum leaf curl aphids Avoid broad-spectrum insecticides that kill beneficials. Plant flowers that attract aphid predators

Use Targeted Insecticides Sparingly

Insecticidal soaps and oils can be used to reduce heavy infestations once leaves emerge. Take care to minimize impact on pollinators and predatory insects. Always follow label directions.

Improve Tree Health and Vigor

Aphids target stressed, unhealthy trees. Ensure proper care and nutrition to make trees less susceptible. Water during drought and fertilize if needed to aid recovery from damage.

RemoveNearby Host Plants

Eliminate aphid-susceptible plants like asters and daisies around the orchard. This deprives aphids of other food sources and limits reinfestation.

Prune Out Heavily Infested Areas

Remove badly infested shoots and water sprouts to quickly reduce aphid numbers. Dispose of clipped foliage – do not compost.

With diligent monitoring, prompt treatment, and proper tree care, you can get leaf curl plum aphids under control before lasting impacts occur. Keep reading for tips to prevent future infestations.

Preventing Plum Leaf Curl Long-Term

The best offense is a good defense when it comes to plum leaf curl aphids. Stop infestations before they start by following these preventative practices:

• Apply dormant oil sprays – Thoroughly coat trees including twigs and buds in late winter to smother overwintering eggs before hatching.

• Remove sucker growth – Prune out water sprouts and suckers promptly to eliminate easy targets for infestations.

• Avoid excess nitrogen fertilization – Heavy doses of nitrogen lead to succulent, vulnerable new growth that attracts aphids.

• Use reflective mulch – Silver colored mulches repel winged aphids searching for trees to colonize in spring.

• Monitor regularly – Inspect trees closely in early spring for signs of leaf curl. Early intervention leads to better control.

• Attract beneficial insects – Keep natural aphid predators around by avoiding broad-spectrum insecticides and planting pollinator-friendly flowers.

• Remove nearby host plants – Eliminate asters, daisies, and other aphid-prone plants around your orchard to limit reinfestation.

With close monitoring and preventative care, you can avoid major leaf curl plum aphid damage. Pay attention for early signs of infestation and be prepared to take action before plum leaves curl.

Frequently Asked Questions about Plum Leaf Curl

To wrap up, here are answers to some common questions about identifying and managing leaf curl in plum trees:

What causes curled leaves on plum trees?

Unlike peach leaf curl fungus, plum leaf curl is caused by aphid feeding. The leaf curl plum aphid is the culprit behind distorted, curled plum foliage.

How do leaf curl plum aphids damage trees?

Aphid feeding causes stunting, reduced vigor, poor fruit quality, and yield drops. Severe infestations over several years can even kill young trees.

When do leaf curl aphids infest plum trees?

Aphids feed on newly emerging foliage in spring. Their populations build rapidly on tender new growth causing leaves to curl around them.

How can you tell plum leaf curl apart from diseases?

Look for colonies of aphids on crumpled leaves. Leaf curl fungus does not cause visible insect infestations on distorted foliage.

What is the best way to prevent plum leaf curl?

Dormant oil sprays targeting overwintering eggs before bud swell are most effective. This prevents hatching aphids from damaging emerging leaves.

Conclusion

Curling, distorted foliage on plum trees is caused by the leaf curl plum aphid rather than diseases affecting other stone fruits. Identify infestations early and take steps like dormant oil application, pruning, natural predators, and targeted insecticides to get the upper hand. Coupled with good orchard care to boost tree health, you can prevent plum leaf curl from causing lasting damage.