When to Plant Marigolds: Zone-by-Zone Timing Guide

Marigolds are cheerful, warm-season annuals that are among the easiest flowers to grow from seed.

They are frost-tender — a late frost kills them — and bloom best once the soil has warmed.

The core rule: direct sow or transplant after all frost risk has passed, once the soil has warmed to about 60°F (15°C).

For an early start, sow indoors a few weeks before the last frost.

Marigolds also double as a useful companion plant in vegetable gardens, helping to deter some pests.

Why Marigolds Are So Easy to Time

Marigolds grow fast, germinate readily, and are not fussy about soil as long as it drains. The main timing constraint is simply avoiding frost.

Because they are warm-season annuals, they should not go out until after the last frost. Once the soil warms to about 60°F (15°C), they take off.

This makes them forgiving: even a slightly late planting still gives a long bloom season into fall.

Direct Sow vs. Starting Indoors

Both methods work well.

Direct sowing after the last frost is simplest: sow seeds 1/4 inch deep, thin to 6 to 12 inches apart.

For an earlier bloom, start indoors 4 to 6 weeks before the last frost and transplant after frost passes.

Marigolds are easy to grow either way, making them a great choice for beginners.

• Direct sow: after last frost, soil at least 60°F (15°C), seeds 1/4 inch deep.
• Indoor start: 4–6 weeks before last frost for earlier bloom; transplant after frost.
• Spacing: thin to 6–12 inches apart, depending on variety.

Zone-by-Zone Planting Windows

The table below shows representative transplant/direct-sow windows by USDA hardiness zone, based on published average last-frost dates.

Coastal and warm zones allow earlier, longer seasons; cool northern zones are later and shorter.

Confirm your exact date with your county extension office.

• Zones 3–4 (last frost mid-May to early June): sow/transplant late May to early June.
• Zone 5 (last frost early to mid-May): sow mid-to-late May.
• Zone 6 (last frost mid-April): sow early-to-mid May.
• Zone 7 (last frost late March): sow mid-to-late April.
• Zone 8 (last frost mid-February to early March): sow March–April.
• Zone 9 (last frost mid-January to early February): sow February–March.
• Zone 10 (no hard frost): sow nearly year-round, avoiding the hottest weeks.

Planting Marigolds Correctly

Sow seeds about 1/4 inch deep in full sun, in well-drained soil.

Marigolds tolerate poor soil but bloom best with moderate fertility and good drainage. Space plants 6 to 12 inches apart.

Water well at planting, then water deeply but infrequently once established. Deadhead spent blooms regularly to encourage continuous flowering.

Marigolds as Companion Plants

Marigolds are popular companion plants in vegetable gardens.

Their strong scent is often said to help deter certain pests, and they are a reliable source of summer color.

For this reason, many gardeners sow or transplant marigolds at the same time as warm-season vegetables like tomatoes and peppers — after the last frost.

Signs You Planted Too Early or Too Late

Sown too early into cold soil, marigold seeds rot or germinate poorly, and a late frost kills young plants.

Sown too late, you simply get a shorter bloom season.

The fix: wait for the last frost, use succession sowing if you want continuous color, and pinch spent blooms to extend flowering.

Related Guides

• How to Grow Marigolds
• How to Start a Vegetable Garden
• When to Plant Sunflowers

FAQ

1. 1

   What month is best to plant marigolds?

   Marigolds are planted after the last frost, once the soil warms to about 60°F (15°C). In most of the U.S., that is from early May (Zone 6) through early June (Zones 3–4). In warm zones, from March onward.

2. 2

   Can marigolds tolerate frost?

   No. Marigolds are frost-tender, and a late frost kills them. Wait until all frost risk has passed.

3. 3

   What soil temperature do marigold seeds need?

   Marigold seeds germinate best in soil at least 60°F (15°C). Sowing into cold soil causes poor germination.

4. 4

   Should I start marigolds indoors or direct sow?

   Both work. Direct sowing after the last frost is simplest. For earlier bloom, start indoors 4–6 weeks before the last frost and transplant after frost passes.

5. 5

   Do marigolds keep pests away from my vegetables?

   Marigolds are widely used as companion plants, and their strong scent is said to help deter certain pests. They also add reliable summer color to the garden.