Quote from Lee Garden Ninja on 8th September 2025, 4:00 pm

Hi @trailguru

Thanks for reaching out with your question about your new Brunnera plugs, and I have to say, your instincts about eelworm are absolutely spot on. Based on your description and the photo you've shared, I believe you've correctly identified the problem - this appears to be foliar eelworm (leaf and bud nematode). So sorry to be the bearer of bad news.

Why this is Eelworm - the tell tale signs

What you're seeing fits perfectly with the classic symptoms of foliar nematode damage. The "brown patches on the leaves and leaf edges are also going brown" you describe matches exactly what we see with Aphelenchoides species - the foliar eelworms that are particularly problematic on a wide range of plants.

Key Diagnostic Features Present: The characteristic interveinal yellow, brown and black blotches you're seeing are textbook foliar nematode symptoms. Even though you mention no obvious tracking, foliar eelworms often cause brown dead patches between the leaf veins that can appear as discrete spots rather than obvious linear tracks, especially in the early stages of infection.

Importantly, foliar eelworms are widely distributed, internal parasites of leaves and can be a particular problem on nursery stock. The fact that these are nursery-grown plugs actually increases the likelihood significantly. This is exactly how foliar nematodes spread through the horticultural trade.

Why It's NOT Fungal or Transplant Shock

Here's why I'm ruling out the more common culprits:

Not Transplant Shock: Transplant shock typically shows as general wilting, yellowing from the bottom up, or overall decline. What you're describing - specific brown patches and edge browning - is much too localised and pattern-specific for simple transplant stress. Brunnera is also quite robust during transplanting when handled properly.

Not a Fungal Disease: Fungal leaf spots typically exhibit distinct characteristics, often being round, angular, or irregular in shape. Fungal spots also typically start small and expand outward in recognisable patterns. More importantly, fungal diseases usually need prolonged wet and humid conditions and take time to develop after spore germination. Your plants are showing symptoms just a week after planting, which is too rapid for most fungal infections to establish and manifest. A healthy Brunnera from my own garden can be seen below for comparison.

Additionally, fungal problems would likely show visible spores in the centre of leaf spots or other fungal signs, which you haven't mentioned seeing, like hairy fuzzy deposits.

Foliar eelworm behaviour and signs

Foliar nematodes are migratory endoparasites, which means they can move into, through, and out of their host tissue. They feed within plants using a stylet or mouth spear to puncture plant cells, inject digestive juices and ingest plant fluids. This feeding activity causes the exact type of cell damage and browning you're observing.

Crucially, juveniles and adults need a film of water to migrate within the soil but also on the stems and leaves of their hosts, which explains how they can spread rapidly through nursery stock where overhead watering is common and eager gardeners water their plug plants as soon as they arrive!

How to treat eelworms

I have to be honest with you - this is one of the more frustrating plant problems to deal with because chemical treatments are only available for use on a commercial scale. For home gardeners, the options are quite limited.

A) Immediate Action Required: You need to remove and destroy any infected plants in your green waset bin.  The eelworms can survive in plant debris and reinfect other plants.

B) Quarantine Protocol: Remove not just the obviously affected plants, but also any susceptible plants growing within 1m of them. This might seem drastic, but foliar nematodes spread readily between plants, and early intervention is crucial.

C) Tool and Area Hygiene: Clean all tools and clothing (including the soles of your shoes) thoroughly so you do not spread the pest to other parts of the garden. These microscopic pests can easily hitchhike on contaminated tools or footwear.

While this is undoubtedly disappointing, especially with new plants, the fact that you've caught it early and identified it correctly gives you the best chance of preventing spread to other garden plants. Your observational skills have potentially saved you from a much larger problem developing.

The good news is that foliar eelworms are quite host-specific, so if you remove the affected plants promptly and follow the quarantine procedures, the rest of your garden should be safe.

Consider this a learning experience rather than a failure. Many experienced gardeners have faced similar issues with nursery stock.

You've done everything right in terms of observation and seeking advice. Sometimes gardening throws these curveballs at us, and how we respond is what makes us better gardeners.

Keep us posted on how you get on with the cleanup, and don't let this put you off - these problems are thankfully quite rare!

Happy gardening

Lee 🌱

You might find these other forum discussions helpful:

• Plant Problems Forum - For other plant health concerns
• First Time Gardener Questions - Building confidence after setbacks
• Where to start with an overgrown garden? - Dealing with garden challenges

Quote from trailguru on 8th September 2025, 7:50 pm

Thank you for responding so quickly. The brunnera plugs have been consigned to the council green bin and the pots and tray I had used when I potted them on sterilised in very dilute bleach. I also emailed the supplier to let them know. 

I did identify it this time but there are, to my inexperienced eyes, other plant problems that look quite similar. Is there a way of confirming the presence of foliar eelworm?