Eliminating Destructive Borers on Ascot Rainbow Spurge

Ascot Rainbow Spurge is an eye-catching perennial prized for its colorful variegated foliage. However, these showy plants are frequently plagued by borers – destructive pests that can quickly kill them. In this article, we’ll explore borers on Ascot Rainbow Spurge, the damage they cause, and effective control methods to eliminate them.

What are Borers?

Borers are the larvae of certain moths and beetles that feed on the inner tissues of stems and roots. Some common borers that attack ornamentals include:

• Flatheaded borers Metallic wood-boring beetles that create oval holes,

• Roundheaded borers Longhorn beetles producing round exit holes

• Clearwing moths Caterpillars of clearwing borers that tunnel plants

These pests are especially problematic for Ascot Rainbow Spurge. They bore deep inside stems and roots, disrupting water and nutrient flow. Left unchecked, entire plants can be killed rapidly.

Recognizing Borer Damage

To control borers, you first need to detect them. Watch for these signs of borer infestation on Ascot Rainbow Spurge:

• Wilting, yellowing, or browning leaves and stunted growth. The earliest indication borers are present.

• Sawdust-like frass or sap oozing from tiny holes in stems. A clear sign borers have tunneled in.

• Hollowed out stems that easily snap or collapse under pressure. Severe tunneling compromises the plant’s vascular system.

• Sudden plant death, especially of younger specimens. Borers can completely girdle and kill small plants.

Act promptly at the first signs of damage to control borers before infestations expand.

Effective Borer Treatments

Once borers are detected on your Ascot Rainbow Spurge, implement control measures quickly. Here are ways to eliminate them:

Manual Removal

• Cut into stems and use a hooked wire to extract borers. Seal wounds with glue.

• Prune and destroy severely infested stems to eliminate larvae inside.

Biological Control

• Introduce trichogramma wasps that parasitize borer eggs.

• Apply Bt (Bacillus thuringiensis) to kill young larvae.

Chemical Control

• Apply systemic insecticides like imidacloprid or acephate as drenches or granules.

• Use bifenthrin, permethrin, or carbaryl as foliar sprays targeting adults and larvae.

Cultural Practices

• Dispose of infested debris promptly – don’t compost it.

• Cover susceptible plants with fine mesh to exclude adult moths.

• Avoid excess fertilizer and pruning stress that makes plants more appealing to borers.

Preventing Borer Infestations

While controlling existing borers is crucial, prevention is ideal to avoid damage in the first place. Here are tips to help deter borers on Ascot Rainbow Spurge:

• Select borer-resistant cultivars like ‘Citronella’ and ‘Red Spurge’ when available.

• Maintain plant health with proper irrigation, nutrition, and pruning. Healthy plants better withstand pests.

• Clean up fallen leaves and debris where overwintering borers may lurk.

• Use pheromone traps around the garden to capture adult moths and beetles.

• Coat the lower 18 inches of stems with latex paint diluted with water to deter female egg laying.

• Apply horticultural oils or insecticidal soaps early in spring before larva hatch.

• Rotate susceptible plants to different beds each season to disrupt borer life cycles.

Protecting Your Investment

Ascot Rainbow Spurge is prized for the unique beauty and interest it offers gardens and landscapes. Protect your investment in these special plants by safeguarding them from destructive borers.

Implement preventive strategies proactively. Inspect plants routinely for early signs of infestation. At the first indication of borers, take prompt action using both physical removal and chemical controls. Combining methods is key to eliminating borers, avoiding widespread damage, and keeping your Ascot Rainbow Spurge thriving.

With knowledge of borer detection, treatment, and prevention, you can enjoy the vibrant colors of Ascot Rainbow Spurge for many years without losing plants to these invasive pests. Your diligence will keep this eye-catching plant looking its best in your landscape.