GardenPerennial Herb · zones 4–9 · 10 varieties
Fennel
Foeniculum vulgare
Apiaceae — the same plant family as carrot, celery, parsley, parsnip and 5 more here. Relatives share pests and diseases, which is why rotation plans group by family.
Fennel (Foeniculum vulgare) is a perennial herb for USDA zones 4–9. It wants full sun and pH 6.5–8 soil, with about 1–2 in of water weekly. It matures in about 60–120 days from sowing, or 60–90 days from setting out a transplant. Watch for aphids and root rot. Below: its full sourced profile from 9 extension sources, plus a planting calendar timed to your frost dates.
Typical dates for zone 6b — set your zone or ZIP for yours. This calendar assumes the crop is started indoors. Timing is a guide from the crop's sourced growth stages; confirm with your local frost dates and extension before you sow.
What we will not put a number on
We do not give a feeding rate for this crop, and that is deliberate rather than a gap. The figures published by extension services are pounds of nitrogen per acre for a production field — they do not convert safely to a raised bed or a pot without knowing your soil test and your fertilizer's analysis, and guessing errs toward burning roots. It is also why every chart you find online disagrees with the next one.
We give watering as a depth per week rather than gallons per plant, because that is how it is actually measured and how the published figures are written. A gallons-per-plant number depends on your spacing, your soil and whether the plant is in a pot — so it would look more precise than it is.
Site & soil
- Hardiness zones
- 4–9
- Sun
- Full sun
- Soil pH
- 6.5–8
- Soil texture
- Loam, Sandy, Clay, Well drained
- Frost tolerance
- Half hardy
No published figure for the temperature frost starts to hurt it and the temperature that would kill it. We looked — where a number is missing here it is missing from the research, not skipped. The crop’s frost and heat tolerance above still applies.
The plant
- Mature height
- 3–6 ft
- Mature spread
- 1.5–3.3 ft
- Spacing in row
- 8–12 in
- Between rows
- 18 in
- Planting depth
- 0.25–0.5 in
- Container size
- 5–6 gal — low end is the minimum, high end is better
- Support
- Self-supportingest
- Grown from
- Direct sow, Transplant
There is no line here for whether it grows fast or slow, because we have no figure to put there. We went looking and wrote down what we read — it is missing on purpose, not because nobody checked.
Water & feeding
- Water needs
- Moderate
- Water per week
- 1–2 in/wk
- Critical water
- Bulbingest
- Feeding
- Moderate
Timing & fruiting
- Days to maturity
- 60–120 days from seed · 60–90 days from transplant
- Harvest cues
- Bulb shoulder visible
There is no line here for how long after the last frost to plant it out, because we have no figure to put there. We went looking and wrote down what we read — it is missing on purpose, not because nobody checked.
Planted again for autumn
- Set plants out by
- late Aug typical · zone 6b
60 days to maturity from setting a plant out — that is what our sources measure for this crop, so this is a date for planting out and not a sowing date, counted back from the first frost above. Not published for anywhere in particular: it is your own frost date and this crop's own figure, which is why it works wherever you are. A days-to-maturity figure is a catalog number for a good season rather than a promise, and a cold month moves it.
Edible parts per source: bulb, leaf, stem, seed, flower.
Compiled from the extensions cited below. Which ones actually show up depends on your region — your extension's local list is the last word.
Fennel foliage and seed are rich in trans-anethole, and extracts of them held back germination and seedling growth across a range of species in testing. Whole-plant effects at garden spacing are milder than the "fennel kills everything" reputation, but the chemistry is real — give it its own pot.
Companion pairings from university extensions; badge = how strong the evidence is.
Different parts differ — the edible part is the bulb and leaf and stem and seed and flower; the notes below flag other parts or preparations.
PetsNon toxic to dogs, Non toxic to cats, Non toxic to horses
Recorded exactly as the source states it — not medical or veterinary advice. If a person or animal may have eaten a toxic part, call Poison Control (1-800-222-1222) or your vet / the ASPCA line (888-426-4435).
Open one and add it to your garden — it lights up here. The rest of the 10 are in the full list below.
| Variety | Type | Days | Color | What it is known for |
|---|---|---|---|---|
| Bronze | Bronze | 60–90 | Brown | |
| Finale | Florence Bulbing | 75 | Territorial Seed Company describes this asslow to run to seed in heat | |
| Florence Heirloom | Florence Bulbing | 80 | ||
| Orion F1 | Florence Bulbing | 82 | High Mowing Organic Seeds describes this asslow to run to seed in heat | |
| Perfection | Florence Bulbing | 72 | Fedco Seeds describes this asslow to run to seed in heat | |
| Preludio F1 | Florence Bulbing | 80 | ||
| Romanesco Heirloom | Florence Bulbing | 90 | ||
| Rondo F1 | Florence Bulbing | 60–90 | Green Vegetable Seeds describes this asslow to run to seed in heat | |
| Solaris F1 | Florence Bulbing | 75 | ||
| Zefa Fino Heirloom | Florence Bulbing | 80 |
- ASPCA Animal Poison Control Center
- NC State Extension
- UC Master Gardeners of Santa Clara County (UC ANR)
- University of Illinois Extension
- University of Maryland Extension
- University of New Hampshire Extension
- Utah State University Extension
We compile bare facts from these university-extension and horticultural sources, never copied prose. 17 of the 19 values on this page carry a citation. The rest are marked est; hover one and it says why — either nobody publishes a figure we could point at, or a person set it and attached no source. Figures vary with climate and seed source; confirm with your local extension before you buy.
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