USDA Zone 12 is frost-free year-round, with average winter lows of 50 to 60°F. There is no last spring frost and no first autumn frost to plan around, so Zone 12 gardeners plant by heat and by the wet and dry seasons instead of by frost dates. The tropical warmth that lets heat lovers grow all year makes cool-season crops much harder. Frost dates here are zone averages and vary by microclimate, elevation and year — check your local extension service for guidance for your exact spot.
Dill is the fast, feathery herb of Zone 12 — the flavour of pickles, fish and potato salad, grown in weeks rather than months. It is also one of the quickest herbs to bolt: dill rushes to flower at the first warm spell, so in the tropics it is a coolest-months crop, roughly December to February, direct sown where it will grow and succession-sown every couple of weeks. Let one plant go to seed and it will self-sow, giving you free dill next cool season.
Zone 12 at a glance
Zone 12 is frost-free year-round, with average winter lows of 50 to 60°F. Plant by the season: the coolest, driest months for cool-season crops, and the cooler part of the year for the best fruit set on heat lovers.
| Detail | Zone 12 guidance |
|---|---|
| Average winter low | 50 to 60°F |
| Last spring frost | None — frost-free year-round |
| First autumn frost | None — frost-free year-round |
| Days to germination | 7–14 days |
| Days to maturity | 40–50 days |
| Sowing | direct sow |
| Best planting window | December to February |
| Harvest | 40–50 days after sowing/transplanting |
| Sun | full sun |
| Soil pH | 5.5–6.5 |
| Spacing | 12–18 inches |
| Water needs | moderate |
| Cold tolerance | hardy |
When to plant dill in Zone 12
Sow dill in Zone 12 only in the coolest months, roughly December to February. Direct sow where it will grow — dill has a taproot and hates transplanting. Seed germinates in 7–14 days and leaves are ready in just 40–50 days, the fastest of the herbs in this guide. Sow a short row every two weeks in the cool season, because each plant has a short life before it bolts. In the hot months dill bolts in a matter of weeks and the leaves turn bitter, so save your seed for the cool season. The planting calendar hub shows the Zone 12 year at a glance, and the December guide covers the coolest month.
Starting dill in Zone 12
Direct sow dill seed shallowly in moist soil and keep it evenly damp until seedlings appear in 7–14 days. Thin seedlings to 12–18 inches apart once they have a few true leaves — dill grows tall and feathery, and crowded plants flop over. Give it a sheltered spot, because tall dill snaps in strong wind, and a light mulch to keep the soil cool and moist. Dill dislikes transplanting, so never start it in trays and move it; sow it where it will grow, and sow little and often rather than one big batch.
Soil, spacing, sun and water
Dill grows best in full sun, in soil with a pH of 5.5–6.5, spaced 12–18 inches apart. Dig in compost before planting and mulch lightly to hold moisture. Give plants room so air moves between them — in Zone 12 humidity, airflow is the best defence against leaf diseases. This crop has moderate water needs: water deeply when the top inch or two of soil feels dry, rather than sprinkling lightly every day, and water at the base in the morning so leaves dry before night. Mulch helps hold moisture. Keep the bed weed-free, and feed lightly with compost rather than heavy fertiliser, which pushes soft, disease-prone growth. The seed-spacing calculator can work out quantities for your bed.
Companion planting
Good companions for dill include tomatoes, peppers, marigolds, cabbage. The companion planting finder can suggest combinations for your whole garden. Rotate crops each year and avoid planting where the same family (Apiaceae) grew last year. A related crop to plan alongside is chives, which shares the Zone 12 calendar, so the two guides work well together.
Pests and problems
The common pests and problems to watch for with dill are carrot rust fly, aphids, wireworms. Inspect plants regularly, especially leaf undersides, and act early: hand-pick larger pests, wash aphids off with water, and remove badly affected leaves. Healthy plants in the right soil and spacing resist pests better than stressed ones. Fungal problems are the bigger worry in Zone 12 humidity: water at the base, space widely, and mulch to stop soil splashing onto leaves. If you are unsure what you are looking at, the pest identifier helper can narrow it down.
Harvest and storage
Pick dill leaves from about 40–50 days after sowing, snipping the feathery fronds as needed and using them fresh — dill loses flavour fast once cut. For seed, let a few plants flower and set seed heads, then cut the heads when the seed turns brown and dry them in a paper bag. Dill seed is the flavour of pickles, and one plant gives you plenty. Dill does not dry well as a leaf, so freeze chopped leaves in ice cubes if you have a glut, or simply succession-sow and eat it fresh.
Frequently asked questions
When should I plant dill in Zone 12?
Only in the coolest months, roughly December to February. Zone 12 is frost-free year-round with winter lows of 50 to 60°F, so plant by heat, not frost. Check your local extension service for your area.
How long does dill take to grow in Zone 12?
Seed germinates in 7–14 days and leaves are ready in 40–50 days — the fastest herb in this guide. Sow a short row every two weeks in the cool season.
Can I transplant dill in Zone 12?
No. Dill has a taproot and hates transplanting. Always direct sow where it will grow.
Why does my dill bolt so fast?
Heat. Dill bolts at the first warm spell, so it is a coolest-months-only crop in Zone 12. Succession-sow small batches and let one plant self-sow for next season.