Fennel Microgreens
Fennel Microgreens is a microgreen in the Apiaceae family. It grows best in full sun with medium moisture, and is listed for USDA zones 4-9. Plants reach harvest about 10–90 days after planting and sit about 12 inches apart.
Varieties
3 from True Leaf Market · sorted by days to maturity▸Bronze10–14 days
Non-GMO; Perennial
This tall, non-bulbing type of fennel has beautiful bronze foliage that creates a great backdrop for any herb garden. The thread-like leaves and seed heads are favored for the spicy, sweet, licorice flavor. It is used fresh on fish, in salads, teas, and deserts. Fresh leaves also can be frozen in a plastic bag or dried and stored in an airtight container. Used as an expectorant and to ease indigestion. Chewing on the seeds freshens the breath. Hung over doors on Midsummer's Eave, it was thought to ward of evil. Perennial hardy to zones 5.
View on True Leaf Market ↗▸Florence10–14 days
Heirloom; Non-GMO
10-14 days. Use fennel microgreens as a garnish for savory or sweet dishes. Fennel microgreens are thin, green and delicate. They have a mild anise flavor that makes them a great garnish for Italian or Indian dishes.
View on True Leaf Market ↗▸Sweet90 days
Heirloom; Non-GMO
Fennel Sweet (Foeniculum vulgare var azoricum) is an excellent addition to home gardens. It is easy to grow, and all parts of the plant are usable in the kitchen and bring new flavor to any dish. Plants are strong growing and regrowth is possible if roots and the base are kept in the ground. Soak seeds for 24 hours prior to planting them. Sow seeds in full sun after the final frost of the season. Thin seedlings to 12-18" apart when they reach 4-6" in height. Cut back foliage to promote more growth, and use fertilizer. Plants don't do well when planted near dill. Harvest after 90 days. Leaves have a licorice and anise-like taste sweet yet spicy. Bulbs can be shredded and used in salads or cooked with meat or fish. Stalks can be chopped and used similar to celery. Use green leaves as a garnish to add extra sweet and spicy flavor to a dish. They can also be dried and used for tea.
View on True Leaf Market ↗
Plant spacing
In a square-foot bed, space fennel microgreens about 12 in apart — that fits 1 plant in each 1-foot square (1×1). Wider rows or containers space the same.
Plan your fennel microgreens planting
Add fennel microgreens to a free GardenDraft plan and get sow, transplant, and harvest dates computed for your ZIP code — with a drag-and-drop bed layout and reminders when it’s time to plant.
Start your free plan →At a glance
Storing & preserving
Best used right away — quality drops fast. Use fresh — refrigerate briefly; not suited to preserving.
General home-preservation guidance — for tested processing times and safety, follow the National Center for Home Food Preservation.
Growing timeline
Companion planting — with cited sources
From US/Canada cooperative-extension publications and peer-reviewed studies. Evidence-tier dots show how strongly each recommendation is backed: ●●● peer-reviewed mechanism · ●● extension consensus · ● traditional knowledge with a plausible mechanism.
Avoid planting near (5)
- CarrotEvidence tier C: Traditional practice with plausible mechanism but limited empirical replicationallelopathy-negative, alternate-host-pest
Fennel root and shoot exudates (anethole, fenchone, estragole) are documented to inhibit germination and seedling growth of multiple vegetables including carrot, tomato, bean, and lettuce. The crop is also a shared Apiaceae pest host. US/Canada extension references consistently flag fennel as a poor neighbor and recommend isolating it in its own bed.
Source: S4, University of Maryland Extension
- Common BeanEvidence tier C: Traditional practice with plausible mechanism but limited empirical replicationallelopathy-negative
Fennel exudates suppress bean germination and early growth in documented assays. Extension recommendation: keep fennel in an isolated bed.
Source: University of Maryland Extension
- Common TomatoEvidence tier C: Traditional practice with plausible mechanism but limited empirical replicationallelopathy-negative
Same fennel allelopathy applies to tomato: lab and field reports of fennel suppressing tomato seedling growth.
Source: University of Maryland Extension
- DillEvidence tier C: Traditional practice with plausible mechanism but limited empirical replicationalternate-host-pest
Fennel and dill cross-pollinate and share Apiaceae pests; extension home-garden references advise not planting them together. Also degrades seed-saving purity for both.
Source: University of Maryland Extension
- Sweet Bell PepperEvidence tier C: Traditional practice with plausible mechanism but limited empirical replicationallelopathy-negative
Fennel (Foeniculum vulgare) releases allelochemicals (anethole and related compounds) reported to inhibit growth of multiple vegetables, with peppers among the commonly cited sensitive crops in extension companion-planting summaries.
Source: S7
Sources cited
- S4
- Oregon State University Extension Service
- S7
- University of Minnesota Extension
- S9
- University of Maryland Extension — Home & Garden Info Center
Care & troubleshooting— extension-sourced, with citations
When to feed, prune & water
Attract beneficial insects and protect pollinators
Protection- Routine carePlant insectary flowers and tolerate light pestsstrong evidence — extension confidence
Grow a diversity of flowering plants (including small-flowered umbels and asters) to feed predators and parasitoids, and tolerate low pest numbers so natural enemies have prey to stick around.
- Routine careNever spray open bloomsstrong evidence — extension confidence
Avoid insecticides on flowering plants and apply any needed sprays in the evening when pollinators aren't active, and favor selective products over broad-spectrum ones to spare bees and beneficials.
Mulch to suppress weeds and retain moisture
Mulch- Routine careApply organic mulch around plantsstrong evidence — extension confidence
Spread a few inches of straw, shredded leaves, or compost around established plants (keeping it off stems) to hold soil moisture, suppress weeds, and moderate soil temperature; wait until soil has warmed for heat-loving crops.
Plan crop rotation
Rotation- Routine careRotate plant families between bedsstrong evidence — extension confidence
Avoid planting the same family in the same bed in consecutive years (aim for a 3+ year gap), grouping crops by family so soilborne diseases and pests that build up don't carry over to the next susceptible crop.
- Routine careSequence for soil healthmoderate evidence — extension confidence
Follow heavy feeders like tomatoes and brassicas with legumes or a cover crop to support soil fertility and structure, and keep simple notes each year so you can track where each family grew.
Thin crowded seedlings to final spacing
Thinning- Routine careThin to ~2 in spacing, then again later· every 3 wks · ~3 wksstrong evidence — extension confidence
Crowded carrots stay small and forked. Thin to about 1 in when seedlings are 2-3 in tall, then to 2-3 in a few weeks later. Snip rather than pull to avoid disturbing neighbors.
Clean up debris and sanitize at season end
SanitationUnusual this time of year.
- Routine careRemove spent plants and fallen debrisstrong evidence — extension confidence
Pull and clear old plants, dropped fruit, and leaf litter at season end, since many pests and diseases overwinter in this debris; dispose of diseased material rather than composting it.
- Routine careClean tools, stakes, and cagesmoderate evidence — extension confidence
Wash and sanitize stakes, cages, and tools that touched diseased plants before storing or reusing them to avoid carrying pathogens into next season.
Something looks wrong?
Describe what you see on your fennel microgreensand we'll rank the likely causes — most likely first, least-invasive fix first.
Bacterial soft rot
Diseasesevere- CulturalRemove rotting plants and produce (manage, not cure)strong evidence — extension confidence
Soft rot can't be cured once tissue breaks down; promptly remove and discard affected plants and produce so the bacteria don't spread to neighbors or other stored vegetables.
- CulturalAvoid wounds and excess moisturestrong evidence — extension confidence
Harvest in dry conditions, handle gently to avoid bruising, control insects that create entry wounds, and improve drainage; cure and store bulbs and roots cool and dry.
- CulturalDon't overwater and rotatemoderate evidence — extension confidence
Avoid waterlogged soil and overhead watering that splashes bacteria, and rotate away from previously affected fleshy crops to lower disease pressure.
Southern blight
Diseasesevere- CulturalRemove infected plants and surrounding soil (manage, not cure)strong evidence — extension confidence
Once a plant collapses it can't be cured; dig out the plant plus the top few inches of nearby soil containing sclerotia and dispose of it, avoiding spread on tools.
- CulturalBury residue and rotatemoderate evidence — extension confidence
Deep-turn soil to bury sclerotia, remove crop debris at season end, and rotate susceptible solanaceous and legume crops with grasses for several seasons.
- CulturalAdjust soil pH and plant earlymoderate evidence — extension confidence
Maintain soil pH at the level recommended for the crop, since the disease is worse in low-pH soils, and time plantings so harvest begins before peak summer heat favors the fungus.
White mold (Sclerotinia stem rot)
Diseasesevere- CulturalRemove infected plants (manage, not cure)strong evidence — extension confidence
There's no cure for an infected plant; cut out and bag affected plants including the black sclerotia, and don't compost them, since sclerotia survive years in soil.
- CulturalOpen the canopy and rotatestrong evidence — extension confidence
Space plants widely, control weeds, orient rows to prevailing wind, and avoid overhead watering at bloom to dry the canopy; rotate to non-host crops (corn or other grasses) for several years.
- CulturalWater at the base, not overheadmoderate evidence — extension confidence
Use drip or soaker irrigation to keep foliage and the soil surface drier, which discourages the sclerotia germination and mycelial growth that drive white mold.
Carrot rust fly
Pestmoderate- CulturalRow cover + delay sowingstrong evidence — extension confidence
Cover the bed with insect netting from sowing, and avoid the spring egg-laying peak by sowing a little later. Crop rotation helps.
Root rot from overwatering / poor drainage
Diseasemoderate- CulturalLet soil drain and water lessstrong evidence — extension confidence
Water root rots like Pythium thrive in saturated soil, so cut back watering, let the surface dry between irrigations, and water at the base rather than keeping soil constantly wet.
- CulturalImprove drainage and aerationstrong evidence — extension confidence
Use raised beds, loosen compacted soil, and add organic matter to improve drainage; remove plants that are already rotted since affected roots won't recover.
Tarnished plant bug / lygus
Pestmoderate- CulturalManage surrounding weedsstrong evidence — extension confidence
Keep broadleaf weeds mowed or removed around the garden, since lygus build up on flowering weeds and move to crops as those weeds dry down; avoid mowing large weedy areas right beside fruiting crops at bloom.
- CulturalVacuum or shake plants to monitor and reduce· every 5 daysmoderate evidence — extension confidence
Tap plants over a light-colored tray to check for nymphs; a handheld vacuum used once or twice weekly can hold low to moderate numbers down on small plantings.
- OrganicTreat nymphs if damage is building· every 1 wkmoderate evidence — extension confidence
For active nymph infestations, azadirachtin or a Beauveria bassiana product can give some control per the label; preserve the parasitic wasps and other natural enemies that help suppress lygus.
Aphids
Pestlow- CulturalBlast off with water· every 3 days · ~2 wksstrong evidence — extension confidence
Knock colonies off with a strong jet of water in the morning; repeat every few days. Light infestations rarely need more.
- OrganicInsecticidal soap - label use only· every 1 wk · ~3 wksmoderate evidence — extension confidence
For persistent colonies apply insecticidal soap to undersides per label. Avoid open flowers.