[LottyLouis]

Hi all. Been doing some research on Tagetes Minuta, which sounds a bit too good to be true - the Marigold that exudes something from its roots that kills bindweed, ground elder and so on and so forth.
My question is - how can it be so selective? How does it dutifully kill stuff that we don't want? Does anyone know if what it exudes from its roots can harm veggies? Has anyone tried this plant?   

[jaydig]

If it does what it says, where can I get some from?  I have a bindweed problem that is driving me crazy

[LottyLouis]

Well - I've never tried it but here are some supplier links:
http://www.chilternseeds.co.uk/item_1222d_tagetes_minuta_seeds
http://www.thenaturalgardener.co.uk/product_info.php?products_id=32
Lots of info about - need to do a bit of research but I'm definitely going to try it out next season. Doodle it! 

[Dai]

Wow! What a plant.
"Uses
Insecticidal - Powdered plants are effective against maize and Mexican beans weevils when mixed with grain but require relatively high concentrations. Plant extract is effective against aphid Brevicoryne brassicae and red spider mites in vegatables. Essential oil is used against ticks. Decoctions show effective control of intestinal parasites in domestic livestock. Secretions from roots are effective against nematodes, worms, insects, fungi and perennial weeds.

Medicinal - It is used to treat gastritis, indigestion and intestinal worms. Externally it is used to treat skin infections and haemorrhoids. The essential oil treats fungal infections like athlete’s foot and boosts the respiratory system. It has antimicrobial, antiphlogistic, antiseptic, antispasmodic, cytophylactic, sedative, emollient, fungicide and hypertensive properties."

Be aware tho, apparently it's very invasive.

"It is an invasive weed on farms. Grows well in disturbed
areas and cultivated beds, usually found in maize farms.
Originally from South America but is now a widespread
weed in Africa, South Europe, South Asia and Australia.
In Kenya it is found in Nairobi, Taita Hills, Voi-Nairobi
road, Kaimosi, Masai Mara, Gatundu, Gathiuru Forest
in Nyeri, Machakos."

I haven't yet found out what it secretes from the roots tho...

[LottyLouis]

Interesting that it - when used medicinally - is used to treat skin infections. One article I read says that you should always wear gloves as it can cause dermatitis! It does seem rather miraculous    and I will be doing some more reading.  Apparently some bulb producer somewhere (Holland?) grew it between his bulbs and found that swathes of ground were free of perennial nasties. I've also read somewhere that the efficacy in the soil increases season on season. 
I just wondered if anyone had actually grown it.   

[Dai]

It would be nice to hear from somebody with practical experience of it.

I found this info tho.
"T. minuta may also leave allelopathic residues in soil (Meissner et al., 1986). The roots exude a polyacetylene derivative which delays germination and reduces the yield of crops grown in soil previously infested with the species."

That's from this website which is a very informative read.
http://www.cabi.org/isc/datasheet/52642

[LottyLouis]

You see, Dai...this is  my Big Question.

... reduces the yield of crops grown in soil previously infested with the species.

Why would it not 'reduce the yield' of my veg?
Gotta do some more reading.   

[Dai]

I'm wondering the same 

I think it only affects certain plant families, think I might have seen potatoes and beans in the list of affected plants on that website but I'm not sure.

Thanks for letting us know about it!

[jaydig]

I'm definitely going to try it next year, but I'll limit it to an experimental area to see what happens first.

[LottyLouis]

There was me scouring the internet for seeds - and then I trip over it this afternoon at my local garden centre! £1.05...and no postage!! 

[Norfolkgrey]

I grew it to get rid of ground elder........

Whilst it did help reduce the spread of it the year it was there it did not however kill it that season or the following. Also they make massive plants - they were at least as tall as me (5'7'') very impressive plants and they did not effect any of the flowers I was growing. I think I got my seeds from Nickys Nursery. They are worth a try to make up your own mind, but I certainly wouldn't bother again 

[LottyLouis]

Ah ha - someone who's actually grown the stuff! Nice to see the other side of the coin - there's always another side to the story. Many thanks Norfolkgrey.   

[Norfolkgrey]

You are welcome. They are also meant to be quite invasive self seeders but I didn't have that issue, but I only grew them the one year. 

[ptarmigan]

I tried one year and they did very little, though to be fair it was the year of 'no summer' when nothing grew very well.  Not sure I'd bother again.