HelpfulGardener.com

Hello all!
This is my first year growing fennel, and I probably should have saved all the seeds for my fall crop, but I couldn't wait!

Some people do not believe in companion planting, but I think it is important to take into account. I have heard that you shouldn't plant fennel with most things because it will inhibit other plants' growth, especially plants in the same family.

So, my question is: should I grow the seedlings indoors away from all my other veggies? And is it also a good idea to germinate the seeds in isolation from the other veggies as well? I only started 6 seeds in a few waxed paper cups, so they can easily be moved away if necessary. Not sure if there being so few makes a difference.

OK. Warning: I do *not* observe the principles of companion planting beyond putting plants together which share similar sunlight / temperature / water / soil requirements.

That understood, be clear about which variety of fennel you're growing. Here in northern California, the kind that grows wild, in marshes, near highways and roads, in the back yard as volunteers, etc., is a very tap-rooted, very long tap-rooted variety. The longest root I personally have dug out was 30"--and I didn't get the whole thing. But my friend, in whose yard I was working, said that the plant didn't come back for several years.

If this is the kind of fennel you're growing from seed, I doubt that it matters what you plant it next to: the fennel will thrive, mostly on neglect and occasional water, to judge by the condition of the wild fennel here ("here" being Sunset Zone 17). Per Sunset, this is the perennial variety, Foeniculum vulgare, and is (no surprise) invasive. We have no rain (generally) from early April through late November, and in some years that might be from mid-March through mid- to late December. Quite a dry spell. The winter rains begin ca. late November/mid-December and end in an average year by mid- to late March.

Since your temps, though, are so much higher during the summer, your fennel may appreciate extra water and/or shade cloth. It's a rare year in the East Bay (Sunset Zone 17) when temps reach the high 90s (38 to 39 deg C), although on the other side of the East Bay hills (Sunset Zones 14 and 15) temps above 100 are pretty frequent, and there's wild fennel there, too--just not as much of it, and clustered more in shady areas near the edges of roads. (Side note: in late July 2006, when I auditioned for a grooming job in San Ramon, it was 113 deg. F there that day during a heat wave. San Ramon is in Sunset Zone 14.)

If, OTOH, your seeds are of the bulbing-type of fennel, we're talking about a whole 'nother veggie. This one, according to Sunset an annual (F. v. azoricum), grows a yummy bulb good for cooking *and* produces seeds at the end of the season on the plants not harvested for their bulbs/roots. These should be planted with other veggies needing full sun and "moderate" water--Sunset's recommendations.

The only exception is for Sunset Zones 12 and 13, where Azoricum is treated as a winter annual. These zones are the low desert areas of Arizona and southeastern California. Cities shown in these zones in my Sunset book are Indio, Brawley, El Centro, Calexico, Blythe, Needles, Yuma, Parker, Phoenix, Wickenburg, Florence, Casa Grande, Safford, and Tucson. Depending on how close Tempe is to Phoenix (I think fairly close?), fennel may be more successful for you during the winter than the summer months. You may need shade cloth during the high summer temps.

Cynthia H.
Sunset Zone 17, USDA Zone 9

Hi Cynthia!

Thanks for all the useful info! You def. saved me a little on trial and error!

Tempe is in the Phx Metro area, it's where ASU is. Unfortunately 113F is an avereage temp in july here. I am in sunset zone 13, and suspected, as you said, that I should have waited and planted the fennel in the autumn, but I could not wait! They might die, but I only started a few seeds, thinking that would be the case; I was unable to stop myself.

As for the fennel, it is a bulbing variety, called Zefa Fino. I should have been more specific, but wasn't even thinking about the wild varieties, I don't think I've seen it here, I wish we had it though! Does it smell nice?

I plan to have it growing in it's own space away from the other veggies, I just wasn't sure if it would interfere with the other seedlings. I don't want an expirement to ruin my tomatoes!

PS-30 inch tap root!!!? Wowza! Do you think a pot will be too shallow? Or is that only the non-bulbing kind?

Hi
I have grown both types of fennel, but now I only have finocchio fennel (the bulbing kind) Fennel attracts a myriad of beneficial insects like lady bugs and their larvae, hover flies, and parasitic wasps. It also attracts aphids like a magnet.

The aphids don't bother the fennel and it is the aphids and flower heads of fennel that attract the beneficial insects. Lady bug larvae are fattening up on aphids all the time.

Fennel does not play well with others, not even members of its own family. Fennel is alleopathic to most plants but it is still useful to have it in the garden just plant it near the dog kennel or off in a corner somewhere. It will still attract the beneficials.

Dill can cross with fennel and coriander is said to interfere with fennel blooming (I have not tried this). It has checked the growth and bloom of plants nearby shiso and tomato (dill will check tomatoes once it blooms too). I planted dill next to fennel one year because I read that dill was probably the only thing that could go next to fennel. The aphids devoured the dill seedlings.

If plants near fennel do not attract the same type of aphid they do fine. Gynuura nepalense (cholesterol spinach), horseradish, and gingers all do fine next to fennel and aren't affected by it. Nothing really bothers gynuura or horseradish except white flies and gingers attract a different kind of aphid. Fennel influences only the plants nearest to it. Relatives should be planted at the other end of the garden but other plants are safe 10 ft away and still benefit from the beneficials that the fennel attracts.

I plant fennel, nasturtiums and marigolds in various places in the garden. I don't really have a problem with green aphids which are the type that flock to the fennel and marigolds. Onions and beans do get black aphids, it does not bother the beans enough, I hose them off. The onions usually only get attacked when they are stressed. The nasturtiums are the trap for the black aphids.

https://www.ourherbgarden.com/fennel-companions.php

More good stuff! 10 feet is manageable. In the end, I was too lazy to make another germination station just for a few fennel, so they are with the other seedlings. Doesn't seem to be bothering anything thus far.

Imafan, if I understand you correctly it mostly interferes with other plants when it is blooming? Most likely I will harvest the bulbs (mmmmmm, drool) when they are fairly small then, cuz it'll be in the 90's by April.

As for the aphids...the ants are farming them in my garden. A few more? No big deal, it'll be worth it for home grown fennel!

Yes, the other plants except for the ones being chewed by the aphids were fine until the fennel and dill bloomed. The dill helped the tomatoes initially, but when the dill bloomed the tomatoes stopped growing and fruiting. Once the dill was taken away, they were fine again.

Aphids will feed on the fennel but also any plant near them. I had a shiso plant next to the fennel. At first it was the best shiso plant in the area. After the fennel bloomed it was the smallest. The aphids did go after the shiso but the lady bugs took care of it.