🌿 When to Plant Fennel

When should I plant fennel?

Plant fennel outdoors at last frost date. For a head start, start seeds indoors 4 weeks before your area's last frost date.

Is fennel frost sensitive?

Fennel can tolerate light frost, surviving temperatures as low as 25°F. This makes it a great candidate for early spring or fall planting when other crops can't go out yet.

What temperature does fennel need?

Fennel grows best between 60°F and 85°F. It can survive down to 25°F, but growth slows significantly below 60°F. Warm nights are especially important once fruiting begins.

How long does fennel take to grow?

Fennel typically takes 65–90 days from transplant (or direct sow) to first harvest.

Should I start fennel seeds indoors?

Yes — start fennel seeds indoors 4 weeks before your area's last expected frost date. This gives seedlings time to develop strong roots before outdoor conditions are ready.

Is it too cold to plant fennel?

It is too cold to plant Fennel outdoors when nighttime temperatures are falling below 25°F. While Fennel can tolerate temperatures as low as 25°F, growth will be slow until nights consistently exceed 60°F. Use CanIPlant to check your local 7-day forecast and get a real-time answer for your ZIP code.

Is it too hot to plant fennel?

Fennel starts to struggle when temperatures climb above 85°F. As a warm-season crop, Fennel enjoys heat but can experience blossom drop and reduced fruiting above 90°F. Consistent highs above that level may delay planting until temperatures moderate. CanIPlant checks your local forecast highs to flag this automatically.

Any tips for growing fennel?

Direct sow preferred — dislikes root disturbance. Keep away from dill and tomatoes.