Good morning from Waco, TX. This is my first post here. I have a problem every year with nematodes on my tomatoes. I have been using marigolds, but I do not believe them to be the right variety, From what I have read this year is that it is the french marigolds. I have only found french double dwarf marigold seeds. Would any of you know if this particular variety fights nematodes? I plan on this year in addition to planting french marigolds I also plan on planting asparagus and chives. All three are said to help deter or stop nematodes.
edit: Oh, and nasturtiums.

Root knot nematodes are a problem here too.
I've read the same about marigolds.... Haven't found the specific variety to put it to a test.

I've read that planting grasses will deter nematodes... have tried winter plantings of rye... not totally convinced yet...

Several links to additional nematode info on this thread:

https://www.survivalistboards....

Hi Asclepius,
I occasionally have small problems with nematodes too. And they only bother my tomatoes and not any of my other crops. Interesting. So I have learned to always pull up the roots on all of my tomatoes at the end of the season so I can discover the problem before it gets out of hand. If it only infected one or two plants in a bed then I have just poured a big bucket of boiling water in the spot. That works. If it has effected a small group then I turned the dirt over every day for a week to dry them out and kill most of them, Then I solarized the whole area and left the plastic on it all winter to keep the area super dry. I only had them come back in the same spot the following year once and so I left the area fallow for the following summer. That worked too. And I always rotate my crops so I won't plant tomatoes there again for at least 3 years.

Anyway, I think these will give you the info you are looking for about marigolds. Happy gardening.

https://ipm.ucanr.edu/PMG/PEST...
https://www.patwelsh.com/pests...
https://www.lsuagcenter.com/pr...

The way the anti-nematode marigolds work is one has to plant the whole field with the right type of marigolds for 2 years running to reduce the nematode population. That means no tomatoes for those 2 years on that patch of land.
The nematodes go into the marigolds and die. One also has to keep the weeds away for the 2 years.
I have never had to deal with that pest, but I was taught about them extensively in college. It may be that things have changed, so take my advice with a grain…

3 types of nematodes, they attack different plants. tagetes is the marigold for repelling other bugs, but draws spiders. Sand here, compost eating sand in a drouth or drown climate, but compost helps deter nematodes - deep piled high rich compost - nothing is an instant cure in gardening, you have to go for the long plan.
By the way, nematodes can spread by soil, water, and wind, so it is a constant battle. I have raised beds, and yes, I still fight nematodes...