[sweetpea84]

This year is the first year I have been able to grow on my allotment as I got it too late to start it off in time for summer last year (had everything in pots on my balcony instead).

I decided to do a spot of companion planting, having seen others do it. I planted sunflowers, french marigolds and french / dwarf beans all together and was quite happy with that. In another bed I planted runner beans and beetroot (for the leaves not for the root).

I was then pointed in the direction of a companion planting chart by another allotment holder who (rightly according to the chart) showed me that these combinations are said not to work.

I duly went off to research it on the internet and was met with lots of conflicting advice. The thing is, my mum plants marigolds and beans together and I have successfully grown beets and runners together in the past. Despite the internet saying that sunflowers and beans don't do well together, so far mine seem to be looking quite happy.

So is everyone on the internet wrong or have i just been lucky not to mess up the veg in the past? Clarification would be most welcome!!

[New shoot]

If you and your mum have successfully grown the combinations that you have just replicated, I really wouldn't worry 

Companion planting is something some people swear by, but as you have found, there are all sorts of different advice out there and it is far from an exact science.  Actually that is true of most gardening.  Ask 6 gardeners, get 12 answers   

Best bet is try a few combos - there are some that pop up a lot - if they work for you, stick with them.  If not, ditch them 

[JayG]

Not many companion planting ideas have much in the way of a scientific explanation as to how they are supposed to work, although there is no doubt that various Tagetes species produce chemicals with insecticidal and insect repelling properties.

Not scientific proof, because I've never not grown French marigolds alongside my tomatoes and other plants, but for what it's worth I've never had a greenfly or whitefly problem in the GH. The effect is probably less outdoors, but then again they help to attract pollinating insects which is obviously helpful for some flowering crops.

Never been convinced about the argument for 'sacrificial' companion planting (e.g. nasturtiums near beans) - to deliberately attract and then establish a large breeding colony of blackfly next to vulnerable crops doesn't make a lot of sense to me.

Even the wackiest ideas are probably pretty harmless in the great scheme of things though - each to their own. 

[Yorkie]

I think beans near onions is a bit of a no-no

[mrsbean]

Snap about the nasturtiums, it then took me 2yrs to get rid of the seeds that kept popping up everywere.