Bronze Fennel

I've heard that bronze fennel may have allelopathic features but I have not been able to confirm this in my limited experience.

Can anyone confirm or deny? Is it only certain plants that don't thrive near bronze fennel?

I also hear it can be weedy with the seeds, but I hear it is manageable.

It spreads, but not like crazy. Birds come and steal the seeds. They lose them. I am in danger of losing them. Would be a shame of such a beautiful plant.
I haven't noticed if they are alleopathic.

I never noticed either free spreading or issues with it inhibiting other plants.
We love how the flowers taste just like licorice all sorts.

Bronze fennel, like other flowering plants in my garden, began to reseed once the soil was healthier, after a few years of mulching. Because of the taproot, it doesn't transplant well unless I choose very small ones. In my area it attracts all kinds of pollinators, but not so much regular honey bees. I can't be sure, but I believe it is a biennial. Currently it is growing in close quarters alongside echinacea, spiderwort, purple sage, lamb's ear, and Siberian iris. No evidence of allelopathy.

j souther wrote:Bronze fennel, like other flowering plants in my garden, began to reseed once the soil was healthier, after a few years of mulching. Because of the taproot, it doesn't transplant well unless I choose very small ones. In my area it attracts all kinds of pollinators, but not so much regular honey bees. I can't be sure, but I believe it is a biennial. Currently it is growing in close quarters alongside echinacea, spiderwort, purple sage, lamb's ear, and Siberian iris. No evidence of allelopathy.

I've had bronze fennel growing in a flower bed for the last 5 years or so. The original clump is still going strong, getting a little bigger each year. In this location it reseeds prolifically; I was just out there this afternoon noticing I have an 8-inch high blanket of several hundred seedlings to dispose of (not difficult, and it smells nice as I yank them out!). It would completely take over if I allowed it to. The foliage is beautiful, the flowers attract a wide variety of pollinators, and it's fun watching the butterflies and caterpillars. I don't cook with it as often as it deserves, but it occasionally makes its way into the kitchen. My 3 young boys enjoy munching on fennel when they're outside playing.
It gets along just fine with grass and wildflowers and I have had excellent success relocating well-established plants all around my yard. It does seem to have a taproot, but I do the best I can (honestly I don't try very hard) and it's very forgiving. The deer mostly don't bother it. All in all it's been a great plant to have!

Good videos at the top of this thread - thanks for sharing.  As to one poster's speculation that bronze fennel is biennial, no, it is definitely perennial.  I have grown it for years and it is a good herb, though it will not make an enlarged stalk for use as a vegetable like Florence fennel.

I am surprised that my own fennel has never spread by seed.  Other posters say it is rampant.  I've been waiting for it to spread, which I wouldn't necessarily object to, but after years have seen zero seedlings.  And I often fail to harvest the seeds of mine, so no excuse there.

Someone also suggested it may be allelopathic.  I grow mine in polyculture and have noticed no such effect.

I grew bronze fennel from seed 6 years ago at my mother’s house, she has a postage size yard and I grew the fennel in a small garden bed. The one original stalk has became a large cluster of dozens of stalks, it is so beautiful in the spring! Last week I spotted 2 swallowtail caterpillars on it, so it must be a host for the larva stage as well! It does seed prolifically for her (zone 7, northern VA). There are dozens of seedlings along the edge of her lawn where it meets the sidewalk, not to mention how it is now taking up about a third of her garden bed. It is planted next to echinacea, gladiola, thyme, yarrow, and horseradish.
I will say, at her location, it attracts a ton of *wasps*. It is planted right by her doorway, and when in bloom, will be absolutely laden with multiple varieties of wasps, and it leans over the walkway so one is obliged to brush against it while entering / leaving the house. However, the wasps are so preoccupied by the bronze fennel goodness, that no one has ever been stung by such an encounter.

We use fennel, including bronze fennel which is now hybridizing with our Italian culinary variety, as a biomass produce, pollinator and pest predator support plant, and for pestos. I do not like strong anise/licorice flavors much, and I still think the pesto is as good as basil based ones, and its a much hardier and more prolific producer. I think having fennel all around my garden and food forest has helped drastically reduce our pest pressure. It is also a pretty plant.

It was too bad that due to wild fennel being considered “invasive”, it’s always been rejected at our local seed and plant exchange.

As for allelopathy, the small blueberries plants growing in fennel’s dappled shade on a hugel bed did better than those without. I would have figured as a “weedy” early succession plant, it would have been bacterial soil associated and not such a good blueberry buddy. I planted 2 dozen blueberry plants with varying degrees of fennel self seeding nearby. As long as I chop and drop the fennel, the bushes have done much better with a deep rooted and dappled shade casting neighbor.

I planted bronze fennel quite some years ago….it was lovely & didn’t spread too much. I made sure to cut the seed heads if I was harvesting them…or to compost if not, so they would not scatter and sow. I did, also, collect the fennel pollen for use in cooking…some interesting culinary uses to check out (do a web search). Unfortunately after a number of years my “bronze” reverted to type and morphed into a typical fennel plant…”bronze” no where to be seen. Oh well, it’s still fennel, just a “basic” presentation of it.

I clicked on this one because I have some bronze fennel seed I need to find a place to plant, and wonder whether my one experience with bronze fennel (it quickly died out) was typical. But I have much more experience with regular green fennel--not the bulbing kind, which no one has mentioned here, perhaps because the bronze variant is non-bulbing. I haven't even tried the bulbs, I grow fennel for the seeds. But after my first experience, I've had trouble keeping it going. That first experience was many years ago. I planted seed from "invasive" fennel growing on the streets of LA, right in a garden bed. It lived for several years, through cold winters and hot dry summers--nothing bothered it, it got to be six feet tall and three or four feet wide and gave a quart of seeds a year. But then I noticed that other things in that bed did not thrive (I specifically remember stunted peppers) so I believe it IS allelopathic--and I decided to move it. I broke two shovels in the process but did get it rooted out--obviously no point in trying to replant it. I have planted seed several times since, including another batch from LA--once I had two plants for two years but they didn't get big and died out. And I use those seeds--I like them in baked goods and spaghetti sauce, but they also are definitely medicinal. I make a tea mix I call Hangover Helper, with mint, camomile, lavender and fennel seeds, which almost always soothes an unhappy gut, regardless of the cause, and I think the fennel seeds are the most important ingredient. Sometimes if I feel heartburn coming on at bedtime I just chew a few seeds, which alleviates it.
So, how much of this applies to BRONZE fennel, I don't know.

I love fennel in the kitchen, but I've never grown the bronze variety. I agree with Mary, the seeds are so useful, especially in Italian cooking.

Oddly enough, I've heard it talked up as a larval host for swallowtails recently, at a master gardening class. They recommended planting a patch or plant of bronze fennel away at the back or corner of the garden, on the basis that associated butterflies strongly prefer it to its cousins, so the bronze fennel can act as a sacrifice or trap crop and support them while preventing them from devouring other members of the fennel/dill family.

I haven't tested this on my own, but considering that caterpillars devour my dill every year, I plan to get some and see if it works.

I have grown bronze fennel for six years now.  Similar to others’ experiences after my soil improved I had a nice supply of volunteers from seed to share with friends.  I am pretty sure every transplant has made it after it wilts completely and looks completely dead and everyone is disappointed.  Sure enough, they pull through.  We eat from ours every day of the year.  Although we’ve never made pesto (I WILL try that!) we eat it straight in the garden in tremendous amounts and of course anytime anyone has a bellyache.

I do feel like I grow it purposefully for the butterflies.  We get hundreds on our established plants and select a few to watch in our terrarium every year just for fun.  I always make a mental note of the week of the year we first see swallowtail larvae on it and interestingly enough it varies by quite a few weeks every year!

It’s a gorgeous plant.  It’s a delicious plant.  It’s very reliable and an amazing pollinator attractor.  

I mostly came here to say it’s also an Acid/Base indicator!  If you brew a tea of bronze fennel it will be purple!  What a surprise!  Adding some lemon or orange juice will turn it a lovely pink and I highly recommend you try a fennel/citrus tea this summer!  Absolutely delicious!

My experience is similar to the others, I planted bronze fennel 5 years ago and have never replanted it. It self seeds year after year, but not too heavily on my compacted soil. However, last year I planted 2 roses in pots and both of them have lots of baby fennel growing in them.

I haven't  notice any allopathic tendencies. I have cosmos that reseed themselves right next to them, as well as hollyhocks.
Pollinators do like it. I would love to have some swallowtail butterflies come for a visit!

I'm certainly happy to find this thread. For no real reason, I wanted to grow bronze fennel -- perhaps originally to draw pests and generally as a perennial. Somewhere I got the idea it was a decorative variety, inedible if not poisonous as commented above. Because my first casual efforts failed, I had to work very hard to get anythng going, and when I finally got one in the ground, it got eaten to pieces and definitely looked dead.

Last year it came back, and I ignored it for other priorities. This year it's gigantic and has multiple stalks. I never noticed flowers this year, but walked down to check it after reading this thread -- the top leaves have been thoroughly defeathered but the lower ones are still fennel-ish; there are yellow flower umbrels in full bloom and others just starting, and a number of volunteers on the slope continuing down into the bull pasture. Very exciting!

I definitely have to move the volunteers because the big daddy was unfortunately placed where we have a thistle problem, and I already have some ideas for those. Any tips on transplanting bronze fennel? I will poke around on the internet of course, but experience-based wisdom here is much preferred. (Ever notice how most of the info 'out there' is word for word copying each other?)

to Ben--I lived in California in my teens, several hundred years ago, and I remember the invasive fennel, remember once sleeping in a bed of them. Here in West Virginia, the invasives are multiflora rose and autumn olive. I sure wish we had invasive fennel, and that it would outcompete those thorny, nasty things!

Sea Skinley wrote:Any tips on transplanting bronze fennel?

In both places that I've had fennel growing, it has self-seeded and volunteered all around the place. If you find smaller seedlings and transplant them carefully and quickly, I think they will survive better than if you try to transplant a big root. The big roots are very deep, wide, tough and tenacious and get damaged when you dig them out.

In the Himalayas at 10,500 feet high, I started with a French packet of supposedly bulb fennel. The bulbs didn't get very fat and the ones I tried to eat were a bit fibrous. But I let one stay as a perennial and it got bigger and bigger for 5 years. I used the immature fat green seeds, and sometimes the foliage, in the kitchen. There were no caterpillars in it.

In Massachusetts in the US, a previous resident had grown bronze fennel, so now it's self seeding all around. I mostly weed it out but there are a couple of spots it's growing right in among a fence and I can't get at it.

I use the foliage of either kind for pesto, and it's delicious. I like to mix fennel leaves & stalks, anise hyssop (Agastache foeniculum) leaves and tarragon leaves. Grind it up with olive oil, lemon juice, nuts (I us walnuts or sunflower seeds), salt, and either garlic or garlic-mustard leaves in season. This pesto is great diluted and used as a sauce over fish or vegetables, or kept firm and used as a dip for raw veggies. It's also good in a sandwich, with or without cheese.

Bethany Clay wrote:I mostly came here to say it’s also an Acid/Base indicator!  If you brew a tea of bronze fennel it will be purple!  What a surprise!  Adding some lemon or orange juice will turn it a lovely pink and I highly recommend you try a fennel/citrus tea this summer!  Absolutely delicious!

Yay, I tried it! Lovely! I compared anise hyssop and bronze fennel tea. They taste pretty similar but bronze fennel made a bright purple where anise hyssop made a typical herbal tea color. When I've used anise hyssop from the greenhouse in winter when the leaves were purple from the cold, the tea was blueish or turquoise.

After adding lemon, the fennel tea turned bright pink, and the anise hyssop tea turned light pink.

Anise hyssop is Agastache foeniculum, a mint-family perennial with a similarly strong sweet anise flavor, and also a pollinator attractor.

I did this with purple-podded snap peas in the past. When I boiled them, the pea pods turned green, and the water turned blue. When I added lemon to the water it turned bright pink, though not quite as bright as this bronze fennel tea does. Anyway fennel tea tastes better than peas tea any day!