Nematodes are often overlooked in nursery and greenhouse production, yet they can quietly cause significant damage:

• Root-feeding nematodes live in the soil and use a needle-like stylet to pierce plant cells and extract nutrients from woody and herbaceous ornamentals. 
• Some species, including ring, stubby root and sting nematodes, feed from outside the root, while others invade and feed within root tissues, making them especially damaging and difficult to detect. 

Because their activity occurs below the surface, nematode infestations often go unnoticed until plants begin to decline, making early detection of symptoms and proactive protection strategies essential to preserving crop quality and value.

Recognizing the signs of nematode damage

Damage from these microscopic roundworms can be difficult to diagnose because above-ground symptoms frequently resemble those caused by disease and other stressors. 

Root-knot nematode galls on Pentas, Nancy Rechcigl, 2025

Root-feeding nematodes can cause several problems, including: 

• ​​Galling, stunting and severe deformation of plant roots 
• Impaired root systems that limit/impede water and nutrient absorption, resulting in plants that are off-color with low vigor 
• Entry points for pathogens 

Foliar nematodes present a different set of challenges. They mostly live and feed within leaves and buds, although they can also live in plant parts under the soil and reinfest plants by migrating up stems and into leaves via films of water. They can also survive in dry tissue, remaining dormant until rehydrated. Foliar nematode damage will appear as necrotic, angular spots or streaks, depending on the veining within the plant. Foliar nematodes occur in more than 100 plant families, most often in herbaceous perennials. 

Because these pests are difficult to detect without testing, it’s essential to conduct routine scouting and sampling. Examining foliage for characteristic damage, along with submitting soil or root samples from problem areas to a diagnostic laboratory, can help confirm which nematode species are present and whether populations are high enough to threaten crop quality.

Building a management strategy

Managing nematodes in ornamental production typically requires a combination of monitoring, cultural practices and preventive treatments. Sanitation, careful plant inspection and attention to crop history can all help reduce the risk of infestations spreading within a production area.

Preventive plant protection tools can also play an important role. Trefinti^® nematicide/fungicide, powered by TYMIRIUM^® technology, offers a systemic approach to managing certain plant-parasitic nematodes along with several key diseases. 

Applied as a drench, Trefinti is absorbed by the roots and translocated throughout the upper canopy to control foliar nematodes and diseases, including Alternaria spp. and powdery mildew. Drench treatments can also protect against Fusarium spp. and root- feeding nematodes. This dual-action protection is particularly important for high-value greenhouse and nursery crops, where nematodes and diseases often work side-by-side to weaken plants. 

When preventive treatments are paired with routine scouting and good cultural practices, growers are better positioned to maintain healthy root systems and consistent crop performance throughout the production cycle.

For more information about incorporating Trefinti into your operation, visit GreenCastOnline.com/TrefintiNematicide.


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