Mustard bad for cover crop?

Hello everyone!

I keep reading that people use mustard for cover crop / green manure purposes on ecologically minded information sources however I also keep reading that mustard "inhibits weeds" on the more botanical type information sources.

I want to plant a wide variety of seeds for generating healthy living topsoil on a former lawn area but I'm concerned the mustard might negatively affect some of the other stuff I'm planting.

Is this an issue or not worth worrying about?

(The tentative list is: Alfalfa, crimson clover, phacelia, white clover, buckwheat, common vetch, oats, daikon radish, yarrow, comfrey, alyssum, dill, fennel, mustard)

Some mustards are allopathic but that's when there in mass patches. And IMO that's usually on disturbed sites where they are healing the soil. I have mustards growing in all my polycultures and wouldnt have it without them.

Mustards are known to hinder harmful nematodes in the soil. There great dynamic accumulators. Eatable in more than one way.

I've never had a problem with mustard. They do inhibit nematodes so they are a good preceding crop for things susceptible to nematode attack. They've always done well in my poly-cultures.

We plant lots of mustard for all of the above reasons and I haven't noticed a problem. I sometimes plant it really thick before tomatoes and then cut off at ground level when I plant. Right now it is growing along with some of my herbs, arugula, anise hyssop, oregano, parsley, feverfew, cilantro, etc. and all are fine

I grow mustard heavily interplanted with other things and I haven't noticed any problem compared to before I started growing them. I find it to be a great easy biomass producer that is prolific in seeds. I would be interested to know any information you find out about mustards effects on remediation.

Thanks everyone. I said "remediation" but I may have used the term incorrectly, what I mean is that it's a pretty barren area with the only topsoil being what is immediately attached to the grass with sandy rocky dirt underneath so I'm trying to build up the topsoil and healthy organisms that go with it. I've heard mustard is useful for that purpose amongst others.

I used giant red mustard in the same bed with cucumbers because it was supposed to protect them from powdery mildew, which troubled me the past two seasons. I couldn't get ANY cucumber seeds to germinate and the ones that were planted as seedlings were definitely stunted/inhibited. I didn't know mustard is allelopathic at the time but all the clues point to that. NOT a good companion plant. There were some very unique pollinators visiting the blooms so IMO worth finding a place for it where it won't impede others' growth.

The plant on your list that causes me a bit of hesitation is fennel.  I've got fennel issues.  I'm seeing a counselor about it.  Our company was overrun by fennel in Viet Nam --- lost 27 men.  When I smell it today, I still get PTSD flashbacks.

It self-seeds very easily and once it sinks it's tap root into the ground, it's a beast to get rid of.  I suppose that would make it a dynamic accumulator, which would be good, but in my world, it's pretty invasive.  A little fennel goes a long way.  Stay on top of it or within a couple of years you'll have a fennel forest.

As I understand it, mustard adds sulfur to the soil and helps prevent fusarium along with those nematodes.

I've been trying Caliente 199 mustard. I'm using it hoping to reduce the effects of Late Blight. It's my opinion that I haven't been chopping it up enough before digging it under. I haven't put a tomato crop in for the last season and a half, in the problem area, so not sure about the results.

I have two excepts that discuss what mustard is best:

According to:
https://www.sare.org/Learning-Center/Books/Managing-Cover-Crops-Profitably-3rd-Edition/Text-Version/Nonlegume-Cover-Crops/Brassicas-and-Mustards


"Precaution. The use of brassicas for pest management is in its infancy. Results are inconsistent from year to year and in different geographic regions. Different species and varieties contain different amounts of bioactive chemicals."


And from seedman.com

https://www.seedman.com/calientemustard.htm

  "What makes Caliente 199 Mustard Blend different from other green manures?
The most important difference is that Caliente 199 Mustards are bred specifically for biofumigation, they contain very high levels of the correct glucosinolates (there are many different types, and some do not produce lots of ITC), and high levels of the myrosinase enzyme, in addition they have the potential to grow into large plants producing high levels of biomass and therefore more green tissue to produce ITC when chopped."

I ordered another 88g package for $3 plus shipping, I think shipping was five something and I also ordered a Giant Belgian Yellow tomato with that shipping. I'm going to try growing the mustard between tomato plants in a new bed and regularly cutting the mustard and mulching it under the plants. I was worried that this wasn't a crop that you could mow regularly so I was glad to see the remark above.