Help - I've got root-knot nematodes

[ViolaAnn]

I destroyed three plants this morning. I suspect there may be more infected. Is there anything that can control root-knot nematodes?

Some of the plants have been looking substandard for awhile, but I finally dug one yesterday. Then today, I dug two more, all of them 12-yr-old plants. Big galls on all the roots.
I suspect there might be a few others.

There is very little on Internet about them and, of course, very few things we can purchase to control the problem.

Do you have any suggestions? Any idea on how long I need to leave the bare spots in my garden?

What's the most likely way I acquired them? And am I going to lose everything in that garden?

Just a couple of pictures attached.

[Chris_W]

Hi Ann,

I don't see signs of root knot in any of those pictures. The big crown pieces make it appear that the plants were much deeper at one time, but those are simply hostas crowns that were growing up and out over time. The roots sloughing off could be a sign of fusarium root rot, though, and that would explain the decline. Fusarium can be a problem in soils that have almost too much bark and too much air circulation present (dries out too quickly) and fusarium can a secondary problem with other soil nematodes like the lesion nematode which is a soil borne nematode only and not a root inhabiting nematode. I don't really see signs of lesion nematodes either but they don't show many obvious signs but can make fusarium get into the roots.

Since I would say fusarium is a greater possibility, and because fusarium can occur when lesion nematodes are present, I would consider a soil drench for fusarium and a soil drench for nematodes. Actinovate is a biological fungicide that can help slow down fusarium. Essentria is an organic essential oil insecticide that when used as a soil drench can greatly reduce all soil borne nematodes, including root knot if you actually had it. Ironically Essentria is rather similar to the stuff the AHS was pushing a while back for foliar nematodes. Though it doesn't actually work for nematodes in leaves it works well in the soil.

Since both of those are considered organic/biological I am sure you would be able to find them in Canada.

I hope that helps - and definitely don't start digging things up. Water like crazy to try and flush the soils through and encourage new growth, and I would start by looking for Actinovate first.

Good luck!

Chris

[ViolaAnn]

Thanks, Chris. I wasn't even sure whether you were checking in here regularly. I hope you really are retired. I'll try to see if I can get my hands on those and give it a try. I DID dig three plants, but am willing to try again, if there's hope. (I DO have some seedlings in the back yard that are getting quite large and need a better location. (I'll attach a pic of one - I call it Heidi Ho after my youngest granddaughter. It's out of 'Spilt Milk' and is going to be large.) 2013

[Chris_W]

I think if you treat for fusarium then it will be okay to plant there. But it can get bad if left untreated, especially if the soil dries out often.

We are between things now but I will post once more is settled. We are still trying to sell but hostas are moving next month and the rest of our plans are coming together.

Good luck.