6' tall fennel is not at all uncommon - it routinely grows to that size here. But the plant is already in flower. If you cut it back now, you will be cutting off all the seeds (which is a good thing here, as it is borderline invasive in my area). The time to cut it back would have been early May or so.

I had cut it back in May when I relocated the swallowtail caterpillars to an enclosure. Should I cut it back again or wait for the seeds to brown? Here, zone 9b, everything grows so quickly.

If you want usable seed, wait for the flowers you have now to go to seed. If you don't mind either way, you could cut it back.

Also, those tiny flowers provide food for some very tiny, very important, very good insects, especially the tiny wasps that destroy caterpillars. I would hope you allow them to keep flowering.

The flowers provide food for tiny wasps? Or the tiny wasps eat caterpillar eggs on the flowers?

Both, I believe. Different species have varied diets and some feed their larvae on animal food but themselves eat pollen and nectar. Many pollinators love fennel.

If you do cut the fennel back dry the prunings for use in cooking. Especially good for baking or barbecuing fish. Fennel also goes well with pork. But personally I let mine flower and just harvest what I need. I don't see the objection to a spectacular 6 foot plant.

I should have known this. Wasps do tend to fly around hummingbird feeders and drink the sugar water if they can. So it makes sense that some wasps eat pollen also.

I gathered the swallowtail caterpillars off my fennel plants and have them in a jar where I am feeding them more fennel... Maybe not as good as the relocation scheme but very entertaining for a one year old in residence this summer.... which by the way, Floral, feels more like England than New York. It is raining AGAIN.

Tom: the wasps lay an egg(s) inside a caterpillar and the larvae eat the caterpillar from inside out... high protein for those babies.

I witness paper wasps eat entire caterpillars--I'm not a fan of wasps but that's the circle of life, I guess. I see my honey bee pollinators with pollen clinging to their fuzzy bodies but wasps do not have hair so not efficient pollinators.

I have been wondering the same thing about my fennel but for a different reason. It looks pretty bedraggled and spent. I too live in Florida zone 9b but the rains seem go around us here. My fennel is planted in a large pot and has to be watered daily or it will wilt. I've never grown fennel and I'm only doing so now for the Black Swallowtails. But I always thought fennel was a "cool" weather plant so I didn't expect it to do well for very long in the Florida summer. But yours looks so much more healthy than mine.

But I have the same question, how and when do you cut back fennel?

Anna

Hi Anna! I would cut back the brown leaves - the ones hanging over the planter. I know what you're saying about the "rain" - lots of thunder lately and maybe a sprinkle or two. Anyway, I have my fennel in an raised bed because the plant got so big I had to move it there. I also have the fennel near my irrigation (raised head) but do water to keep the plants hydrated. If you have an irrigation head, you can try to move the pot so it's close to the spray.

I've never cut back my fennel nor seen any reason to, other than to harvest what I want. Anna, is yours herb fennel or bulb fennel? The habit is odd for the fennel used as a herb. And how many plants are crammed into that container? They look very crowded which could be why they're spindly and stunted. Heat doesn't bother it but humidity might since it hails from the Mediterranean. It's a seaside plant in the wild and likes good drainage. It doesn't mind dry soils but it has a taproot that can access deep moisture. That could be another reason yours is not growing well in a container. It's perennial so is never actually 'spent'. It will return year after year and retains year round basal foliage.

Hi floral_uk. I don't know which fennel it is. I didn't even know there were 2 kinds until a week ago. I thought there was only "bulb". So I've attached a photo of the base of the plants in the pot (after I took missmandylee's advice a trimmed out the brown stuff). Let me know if you can tell which fennel it is. And yes, there are multiple plants in the pot. It gets direct sun from noon on. It was very healthy and beautiful from March-Jun 1 and the Black Swallowtails were loving it but when it started hitting 90 degrees F with heat index of 107, it would wilt and water would revive it but that's not working any more. If this is the type with a long tap root then they are probably pretty miserable in a pot. Should I try transplanting them in the ground?

In the area of FL where I live there is no soil, it is only sand. So pots are a good way to use nice rich purchased soil without having to dig out tons of sand. But after seeing missmadndylee's plants in raised beds and reading your comments, I may need to consider planting the fennel in the ground for the fall. I recently purchased Bronze Herb Fennel seeds. Should I try planting them now or wait until fall (we rarely have freezes here)? In the ground or keep to the pot?

Any help would be appreciated.

Anna

Anna, I live in a similar place. I live about 25 miles west of Disney on a sand hill. I grow my fennel in pots and mostly in the shade. I suggest you put yours in the shade also. It's just too hot for them to be in full sun here and they do really well in mostly shade--not total shade. I have bronze fennel and green fennel. I haven't noticed any preference by the black swallowtails. It seems to me that your pot is pretty deep, so they should do okay. If you move it you may pull up some roots, but they should grow back.

Anna, you have bulb or Florence fennel there. Because it is sowed so thickly it hasn't grown to its full potential and hasn't formed much in the way of bulbs. Although it does put up flower stalks they don't grow as tall as herb fennel. It's quite hard to grow well as it needs rich soil and plenty of moisture. Herb fennel is much easier.

Tonight’s giant fennel. Didn’t take much rain to get this big! I know I have both herb and bulb fennel and have eaten some but grow it primarily for the swallowtails. Tomorrow, I will clean it out of debris and check for eggs and caterpillars.

You're so lucky to have swallowtails. They're vanishingly rare here and the single species we do have doesn't eat fennel. My fennel is purely culinary and ornamental.

You need to move to Florida, Floral:)

Great photos, Anna.

I just came back from outside and noticed that I have four very large cats on my fennel and a bunch of small ones. They will eat the fennel to the ground, but it comes back. I have four different bunches; so usually they can't eat all four in the same few weeks.

Thanks Tom. Do you think I would have success if I planted Bronze Herb Fennel seed in a pot now in June?

Anna

If you measure success as in growing the fennel then I would say yes. I'm not sure it would be big enough in time to host many black swallowtails, but it might be. If not, you will get a very good start on next season. I say, Go For It.

Is there a reason you can't plant it in the ground? It would be much happier and less trouble to you.

Hi Floral,

I know this sounds strange but this is Florida, one of the strangest places in the world. :) My home is built on "fill sand", most homes in peninsular Florida are. There is no soil, no nutrients, and lots of nematodes in the sand looking for anything organic to eat. So one either has to dig out a lot of sand and replace it with purchased soil or grow in raised beds or pots. If you dig out the sand it's got to be a large area because if you just dig an appropriate size hole for a transplant and back fill with good dirt, the plant will not thrive. There's not enough soil to produce good nutrition. My problem is what to do with all the sand after I dig it out. I live in a "deed restricted" community (very common in FL) which has rules about the yard. And it's a small yard. There's no place for me to put the sand such that it is not an eyesore. I would have to pay someone to haul it off every time I wanted to plant something. It is just a real pain that I never new about until I moved here. I thought Florida.... I'll have a great garden in Florida. I grew a much more beautiful and productive garden in AR, MN, ID and CA. Most people think of Florida as tropical and lush and in some natural areas it is. But in manmade subdivisions built on "fill sand", a garden in FL is a "hard row to hoe". :)

I feel your pain, Ana. Most of Florida is near sea level and the top soil is mostly sand. It is a challenge growing things here, but once one learns what to do and not do it can be a wonderful place for gardeners.

For me it's great. But it has been a learning experience.

There are two major things to know to grow things well here.

First, one must use the right soil additives. It's best to use time-release fertilizer, so that the nutrients aren't all washed away in the sand. Organics are also good. They tend to release slowly and also encourage the growth of friendly bacteria and microbes that plants need to grow. Espoma products are excellent organics. I also add alfalfa pellets when I plant anything. I put some in the hole with the new plants and then often around them also. Alfalfa does not burn and it is excellent at encouraging microbes necessary for plant growth. I use a thick layer of mulch around my plants to hold moisture and keep the weeds from taking over.

The second thing is learning what grows best here and what doesn't. There are many plants that are very susceptible to nematodes. One simply has to learn to not plant them. For example, roses and gardenias that are own root will soon decline due to nematodes. However, roses on fortuniana root stock and gardenias on certain grafted root stock do well. I cannot grow zinnias, most lantana, or snapdragons. On the other hand azaleas and camellias do very well.

Not enough room here to mention all the hummingbird and butterfly plants that do well here. Florida, after all, has three things in abundance that most plants love-- sunshine, water and heat.

I've been to Florida. In the U.K. fennel has naturalised near the sea and along roadsides. It likes shingly, sandy areas and isn't fazed by poor soils. In fact that's where it thrives in the wild. Where I grew up it flourished along a beach road where it was occasionally covered by a high tide. Other than the nematodes I'd really consider risking the price of a packet of herb fennel seed to try some in the ground. Bulb fennel is a different matter. It needs more nutritious and moist soils.

Wow, Floral I had no idea that fennel grew in such places in the UK. I just bought 2 packets of Bronze Herb Fennel seeds so it sounds like experiment time! I'll plant some in the ground in a sunny location and see what happens.

Tom, thanks for all the information and support. Especially reminding me about alfalfa. When I lived in Tampa I used it in my rose garden (all on fortuniana), but I didn't think to use it on other plantings here. (I no longer grow roses.) I am very surprised to hear azaleas and camellias do well for you, that's wonderful. They are such acid and compost loving plants.

Anna

We seem to have a lot in common, Anna. I also used to be a big rose grower. I tired of spraying and watering and fertilizing and deadheading. They are beautiful flowers, but a lot of work if one wants to have good blossoms. I still have a few Louis Phillipe. They just don't die.

I no longer plant camellias or azaleas, but I try to take care of the ones I have. I don't fertilize them enough. As you mentioned, they like acidic fertilizers. Espoma makes an excellent organic one.

The one butterfly plant that I kept trying to grow and failed was the Buddleia (sp). There are so many different kinds and they are fragrant, attractive and the butterflies and hummingbirds love them. However, the nematodes love them as well...

"Alfalfa does not burn "

Not precisely true :-) Alfalfa meal begins to break down/decompose very rapidly and that can and does create sufficient heat and N release to burn plants. It is recommended to not let alfalfa meal or pellets come into direct contact wth plant roots because of this.

Alfalfa and blood meal are two organic amendments/fertilizers that have this ability.

Thanks for the info gardengal48. Good reminder on no root contact.

I quit rose gardening for same reason. I didn't want to spray insecticides and fungicides any more. I figure I've killed enough insects and contributed to their decline in my lifetime.

I too, think buddleia is one of the best butterfly plants to have that doesn't grow well in FL. I planted 5 across the back of the property in full sun and sand (before I learned about sand planting) 7 years ago. I babied and tended these bushes but every year or so one died. There is only one left. I thought for sure it was a goner but over the years the cyprus trees on the corner of the property grew, too. They now put the Buddleia in shade for half the day. The bush has revived and has produced more flowers this year than ever before. Who would have guessed how much a little shade could do for a sun loving plant? Of course, I'm fertilizing and watering to support this revitalization but I really think the partial shade was the key. I don't remember the variety name but the purple flowers have orange/yellow throats.

I know folks in areas where Buddleia grow well will say this is a pitiful plant but I think it's pretty darn good for FL. :)

So I doubled down on the partial shade theory and planted 2 new buddleia for the first time in years this past March. I did dig out a 5'x2'x20" trough, replaced the sand with purchased soil and planted in partial shade. The variety is Buzz Hot Raspberry. It's worth the work and experimentation because the butterflies love them more than anything else I've planted.

I'm keeping my fingers crossed the new buddleias will last a couple of years.

Anna

I have read that buddleias do well near cement, because the cement discourages nematodes. Is your survivor near any kind of concrete? Good luck with your new buddleias, Anna. They have a good chance of lasting a few years if you take care of them. They really hate wet feet, so the sandy soil will at least be well drained.

The large red, lavender and purple porterweeds have taken the place of buddleias for me. They aren't really fragrant, but the pollinators love them. They have the advantage of not having to be deadheaded, and, of course, the nematodes don't seem to bother them.

Starting to see Pipevine Swallowtails now on a daily basis. I see lots of Zebras and Monarchs every day and a few Giants, Sulphurs and Fritillaries every day. Looking forward to seeing more Tigers now that the rains are here.

The old Buddleia is near a man-made stone retaining wall. Which I had rebuilt in Oct 2017 which made it taller AND moved it closer to the Buddleia. All 5 were planted along the old retaining wall but not as close as now. So that could be improving the plants health by chasing off the nematodes. Thanks, something to definitely keep in mind.

Are you seeing Zebra Longwings or Swallowtails or both?

Anna

Lots of Longwings. I only see the swallowtails when I ride my bike at Lake Louisa State Park. I tried for years to grow Paw Paws, but the only kind that I could grow were the big ones from up north---which the Z. Swallowtails here don't use.

First time growing fennel. Intended for butterfiles. Two plants, growing very well. Roots have plenty of soil depth into which to grow, and I will continue to repot for that purpose (probably ground planting at some point). Longevity of these plants is the consideration in the question : Will it be beneficial to separate the five "entities" shown into five plants? If so, then when? (i.e. sooner than later? vice-versa? unimportant wlhen?)

Floral, regarding tap root : My plants, partially pictured, much larger now, grow only fine roots. Impressively abundant masses of them. Deep.

Question to any /all : Do caterpillars like the yellowed leaves?

I don't really know if you should try to separate them or not. What I would probably do is separate one or two and see if it will root. If so, then you could root more. If not, then at least the main plant should be okay.

Floral, with regard to your mention of taproot, mine have only fine roots. Impressively abundant masses of them, deep. Much of their length tears off during transplanting; no problem.

Four, your plants are Florence fennel, a delicious bulb like vegetable, not the taprooted herb fennel. Even if I had swallow tails it would be very hard for me to forego Florence fennel in their favour. I'd grow the herb which produces much more foliage and we could share. Each Florence fennel plant has multiple stems, similar to celery. You have two plants. Those stems are not separate plants and they won't divide. Separating them out would kill them. And repotting will do them no good either.

Originally in one-gal pots; roots and medium a solid mass. I have repotted each twice.

Please expand on the no good.

For use as a vegetable Florence fennel needs to be grown warm, rich, moist and fast. Repotting or transplanting are not recommended because it causes a hiatus in growth. However I suppose if you only want it as foliage for cat food and are not interested in producing good bulbs for eating it doesn't really matter. But what is the purpose of repotting?

Rhetorical question?

No. I'm interested in why you think they need a different container. They're pretty far established and I can't see any reason for moving them at this point.

I am going for much caterpillar food. Plants (that can grow big) grow less big in containers in which roots are cramped. There must be at least enough medium to hold the optimal amount of moisture and air and nutrients. I add medium by repotting when roots grow out of holes.

Makes sense, Four. When the black swallowtails arrive, which should be any day now, they are going to eat the entire plant, or both plants or even more if you get them. One butterfly might lay 20 eggs. If they all hatch they tend to consume whatever plant they are on. i have four large fennels; three are on one side of the house, but separated and the fourth is on the opposite side. I don't like to put the cats in cages, so I move them from plant to plant. Normally I have at least one plant with enough growth to support some caterpillars.

Florence fennel doesn't grow a lot bigger than yours is now. The bulb swells but the foliage never attains the six feet of herb fennel. Moving it at this stage will stall its growth, possibly killing it, and there's still plenty of room for it in that pot.

Second repotting at some point after photos above. Owing to my technique, appearance was unchanged, and growth continued.

> "foliage never attains the six feet" It helps me much to know this.

One of them now thinks that it is maize :