How much should I believe in my companion planting book called "Tomatoes Love Carrots. Specifically it states that no other vegetable likes bulbing Fennel. Well, I have to put it somewhere! Any advice?
From a quick search fennels seed seem to be allelopathic to other plants. This link gives some information. http://plantphys.info/research/allelopathy.html
This site http://vro.dpi.vic.gov.au/dpi/vro/vrosite.nsf/pages/invasive_fennel tells about fennel becoming invasive possible by inhibiting plants around them.
The question is how far away do you have to plant it.
I have always heard it was detrimental to other plants but have never tried otherwise.
You might consider planting the fennel in an ornamental bed (flower bed maybe). It is pretty foliage and a nice backdrop to flowers.
This year I was very successful growing Fennel. It took me a while understanding when to start the seeds in my zone.
I took a class that though me to not pull out the vegetables from the soil, instead to cut the root 1" below the surface.
In this way I would disturb the soil biology.
So I did ... and some of my Fennel came back.
It is too hot for the bulb to form ... but I am letting it grow for the butterflies.
It is growing between the peppers and no problems so far.
i have planted fennel and dill in the extreme perimeters of my vegy garden..
i read or heard that the flowers of these plants attract wasps..which mine do..
here in utah..we have plenty of grasshoppers.. but not in my garden..
the wasps keep the hopper population down.. i dont bother the fennel/dill much..and
the garden seems to get the benifit of few hoppers to chop on my plants !!!