Theory

My mom has this theory. She noticed, that she never has to weed her Datura. I mean never. She wondered if the plant creates some kind of toxin (or something) that inhibits germination (or something) discouraging other plants.

I was wondering if anyone has had similiar experience with this or if she is just experiencing some other kind of phenomenon.

I'm assuming she grows them alone? No other ornamentals nearby?

No other ornamentals. They are very much all by their lonesome in every respect. Well, except for the lawn.

Now you've got me interested - someone on DG must know this?

If her hunch is right and they do have a habit of discouraging competition. I'd love to try and see what they do against Blackberries.

By the way, they are just common Datura. inoxia I believe.

I was thinking morning glory and ivy and buttercups, myself...and even the "common" ones are glorious in shape and scent, are they not?

They are glorious. I'm putting in my first bed of them this year and I'm so excited!

I was sent seeds of the purples by a generous DG-er, and I am, like you, anticipating like mad - they are so gorgeous.

renwings... is the area where ur mother plant datura heavily mulch? i wonder.....

i have grown different varieties of daturas and always have weeds growing around the datura plant. i do not mulch the datura since they grow wildly in the desert.

No, she used no mulch under them.

When I think back on the days ,as a kid I would "bring in the cows",and was told the same thing ,that nothing would grow around them,and that they were poision,we called them "loco jimson weeds".I know they grew out by themselves,but just thaught that the cows knew better than eat them,but would eat around it.Now you have provoked my memory.Mike

I have read a few books about datura and none of them mentioned this at all.

I had a sacred datura (jimson-weed) that grew to 4' across and 4' tall when I lived in Fontana, Ca. Nothing grew in it's shade. Not a weed, no grass...bare dirt. But it was a glorious plant!

And although they do grow wild here, especially where the soil has been slightly disturbed, (like along roadsides), they tend to spread out, rather than up. I'll have to stop and peek under some of them and see what I find...*s*

They crowd other plants along the roadside in Mexico .
My wife is from there and when the relatives start talking , I go look for them . Never know , you might find a sport .
Anyway , if you don't know what they look like you will never find one , the plants along side grow and touch them .
Maybe you have a different varity .
If you save some seed pods , someone here will take them grow them , thank you and tell you what they find .
By the way , You mentioned you have several books on datura's . I only have 2 would like the names of the ones you have . [ book name , publisher , auther ] If you can find them easily .
Mine are -
Brugmansia and Datura - [ Ulrike and Hanns-Georg Preisse ]
Engelstrompeten - Angels trumpets [ Monika Gottschalk ]

I grow mine, several varieties, in my butterfly garden among other perrenials and all seem to grow together just fine

Hey guys, I have my double yellow Daturas growing, and my 4'oclocks seeds are coming around them them (like hair on a dogs back), plus one of my kolotcha plant is in the same pot with a datura growing with it! I don't see any of the other plants caring. Thanks, Krispi

Allelopathic effects of Datura stramonium

Datura is an important weed in USA, Australia, tropics and subtropics. It contains a number of alkaloides mainly Scopolamine and Hyoscyamins which are produced in the roots and translocated to the leaves and seeds. Datura is a common weed of Chhattisgarh and its allelopathic effects on many agricultural crops have been reported (Oudhia et al., 1996b and 1999d; Oudhia and Tripathi, 1998c). In experiments conducted at IGAU, Raipur, Datura stem + leaf extract of 264 hours was identified as promising extract whereas stem + leaf extract of 216 hours and leaf extract of 168 hours were identified most harmful extracts (Oudhia et al., 1998g). Besides these weeds, allelopathic effects of leaf extracts of Aeschynomene americana, Abutilon indicum and Euphorbia hirta were also studied. These extracts produced positive (inhibitory) allelopathic effects on germination and seedling vigour of chickpea seeds (Oudhia, 1999g).

The experiments are still in progress at IGAU, Raipur. In these studies, the isolation of allelochemicals from extracts was not done because of lack of laboratory facilities and high cost of chemical analysis. However, from these studies many basic informations have been gathered. The studies revealed that (a) All weeds are not harmful, (2) Different parts of weed have different allelopathic potential, (3) The method adopted for preparation of extracts can alter the allelopathic potential of weed parts. The studies also indicated that there is a tremendous scope of utilizing the extracts of different weeds for presowing soaking of chickpea seeds in order to stimulate the early germination and seedling vigour.

The term Allelopathy is derived from two Greek words Allelon means each other and Pathos means to suffer i.e., the injurious effects of one upon another. However, Molisch (1973) coined this term which refers to all biochemical interactions (stimulatory and inhibitory) among plants, including micro-organisms. It represents the plant against plant aspect of the broader field of chemical ecology. Some authors have used the term in a more restricted senses to describe only the harmful effect of one higher plant upon another.

Allelochemicals which inhibited the growth of some species at certain concentrations may stimulate the growth of same or different species at lower concentrations (Narwal, 1994). Allelopathy is relatively a new branch of science (Lal and Oudhia, 1999). With the help of allelopathy, weed-crop, crop-weed, crop-crop and weed-weed interactions can easily be explained. Under field conditions weed infestation is one of the major factors responsible for yield reduction in crops. Historically, most investigators have attributed these losses to various forms of competition between the weeds and crops and allelopathic interactions between them were not considered. However, findings after 1950’s have shown that allelopathic interactions between the crops and weeds were also partly responsible for such losses in crop yields.

Allelochemicals, secreted by weeds, may have a direct negative influence on the germination of seed, as well as the growth of the crop (seedlings and the later growth stages).
Weeds may also have an indirect effect on crops through, e.g. the transfer of crop diseases.
However, allelopathy may also be the mechanism underlying the dominance of the more aggressive weeds under certain conditions of cultivation that make the environment unfavourable for the crop (in other words, the weeds flourish, but the crop struggles to grow)
Example 1:
The thorn-apple (Datura stramonium) contains many alkaloids in the seed-pod (testa) which may remain present for up to 7 months, while the seeds of the weed are in the soil.
The alkaloids must first be leached from the testa before the seeds of Datura will germinate (probably an ecological mechanisms of germination control)
Once the alkaloids are leached; and they once again serve as powerful inhibitors of other plants in the immediate environment.

So , if i dry out seed pods , make a podwer of them , they will stop weeds ?
[ 2 many people want seeds to be destrying them , but The shells are fair game . ]
Is there another book besides
Brugmansia and Datura - [ Ulrike and Hanns-Georg Preisse ]
Engelstrompeten - Angels trumpets [ Monika Gottschalk ]

I think what they're talking about here are the common weed daturas. I don't know whether the allelopathy applies for all varieties.