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Viburnums are a diverse group of flowering shrubs that are very popular in the garden. Unfortunately, they’re often preyed upon by a wide range of pests. Keep reading to learn more about the insects affecting viburnums and how to go about controlling viburnum insect pests.
How to Get Rid of Nematodes on Your Arrowwood Viburnum Shrub
If you’ve noticed that your arrowwood viburnum shrub is looking a little lackluster lately with stunted growth, yellowing leaves, and poor flowering, there’s a good chance it could be suffering from a nematode infestation. Nematodes are tiny parasitic roundworms that attack plant roots and can seriously impact the health of viburnums and many other shrubs. Getting rid of nematodes on your arrowwood viburnum will take some effort, but it can be done organically without resorting to harsh chemicals!
In this comprehensive guide we’ll cover everything you need to know about identifying and treating nematodes on arrowwood viburnums so you can restore the beauty and vitality of your plant.
Identifying a Nematode Problem
The first step is confirming that nematodes are in fact the issue. Look for these common symptoms:
- Stunted growth or reduced size of leaves and stems
- Wilt, yellowing or browning of foliage
- Lack of flowers and berries or poor fruit production
- Damaged or rotten roots with knots or galls
You may also notice general decline as the shrub struggles to take in enough water and nutrients due to the damaged root system. Check the roots carefully by gently removing the plant from its container to inspect for signs of nematodes like swelling, lesions, or rotting.
If you confirm nematodes, don’t despair! There are several effective organic control methods we can try.
Organic Nematode Treatments
Nematicides (nematode killers) are available but often contain toxic chemicals. Organic approaches are safer for people, plants, and the environment. Here are some options:
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Neem oil – This natural pesticide has nematicidal properties. Mix it with water according to package directions and drench onto the soil around your viburnum.
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Beneficial nematodes – These microscopic worms prey on harmful nematodes. Apply them early in the growing season and reapply every 2-3 weeks according to label instructions.
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Marigolds – Certain marigold varieties release chemicals from their roots that repel nematodes. Plant them around your viburnum shrub.
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Solarization – Clear plastic sheeting can heat up the soil and kill nematodes. Cover treated areas for 4-6 weeks in summer.
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Crop rotation – Avoid planting other nematode-susceptible plants in the same spot. Rotate between plant families.
For best results, combine several methods like using both beneficial nematodes and marigolds. This overwhelms the harmful nematodes so they cannot develop resistance.
Preventing Reinfestation
Getting rid of your current nematode problem is important, but preventing future infestations is key to keeping your arrowwood viburnum healthy long-term. Here are some tips:
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Inspect new plants very carefully before bringing them home. Nematodes can hitch a ride on new nursery stock.
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Disinfect tools after working in nematode-infected areas to avoid spreading them around your yard.
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Remove any roots, debris or diseased foliage during fall cleanup and dispose of it in sealed bags. Don’t compost anything suspect.
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Improve drainage and aerate soil regularly to discourage nematodes who prefer compact, waterlogged earth.
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Fertilize viburnums with a balanced organic fertilizer to strengthen the plant so it’s less susceptible.
By taking a multipronged approach, checking roots vigilantly, and removing and destroying any reinfested plant parts immediately, you can get nematode populations under control and restore health to your arrowwood viburnum. Be patient, as it can take time to correct extensive nematode damage. But with persistence and care, you can defeat these tiny pests and get back to enjoying the beauty this classic shrub brings to your garden.
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Common Pests on Viburnum
Here are some of the most common viburnum pests and methods for viburnum pest control. Aphids – While they don’t cause much damage, aphids can cause curling in new growth. They can be gotten rid of with a steady stream of water from the hose, insecticidal soap, or horticultural oil. Thrips – Thrips can cause purple spots on leaves, curled and dropped leaves, and dropped, unopened flower buds. Try to prevent thrips by keeping weeds under the shrub to a minimum. Spray with insecticidal soap, if necessary, but be careful, as there are many beneficial insects that feed on thrips. You can also introduce beneficial insects such as lacewings, ladybugs, and predatory mites to the garden. Southern Red Spider Mites – The leaves turn gray/brown and drop when these red spider mites are present. Mites can be knocked off with a strong spray from the hose or treated with insecticidal soap. Scale – Armored scale cause leaf drop, discolored leaves, and stunted growth. Light infestations of scale bugs can be scraped off by hand, and heavier ones can be treated with insecticide. Other insects affecting viburnums include: Weevils – Weevils chew on the edges of leaves. While they’re not usually dangerous, the damage isn’t pretty. Spray the leaves and ground below the shrub with insecticidal spray to kill the adults. Repeat every two to three weeks to kill each generation. Asiatic Garden Beetles – Flowers, leaves, and new growth is skeletonized when Asiatic garden beetles are around. Common types include the Japanese beetle. Remove adults by hand and introduce nematodes to the soil. Dogwood Twig Borers – Dogwood borers will dig out holes in the stems, leaving sawdust behind. Crush eggs in early summer. Stick a wire into every hole you find to kill the borer inside. Viburnum Leaf Beetles – Plant resistant viburnum varieties to avoid viburnum leaf beetles. Prune away egg-infested branches during the winter. Introduce lacewings as beneficial insects.
How to Sustainably Manage Parasitic Nematodes in the Garden
FAQ
What kills nematodes instantly?
What is a home remedy for nematodes?
What insecticide kills nematodes?
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Chemical name
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Trade name
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Formulation
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Thionazin
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Nemafos
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Granular or emulsifiable liquid
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Ethoprophos
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Mocap
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Granular or emulsifiable liquid
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Fenamiphos
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Nemacur
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Granular or emulsifiable liquid
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Fensulfothion
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Dasanit
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Granular
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