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Herbs, Flowers & Specialty CropsMarigold Planting Calendar
Marigolds are among the easiest flowers to start from seed. They want warmth, sun and enough room, and they will bloom from early summer until frost if you set them out at the right time.
Key points
- Plant marigolds after your last frost, when the soil is warm.
- Seed directly or start indoors a few weeks before transplanting.
- Thin and space plants to match their mature size.
- Deadhead and shear back to keep flowers coming until frost.
When should you plant marigolds?
Marigolds are tender annuals that frost will kill, so they go out after your last spring frost, once the soil has warmed. Iowa State University Extension notes that most annual flowers are direct sown after the last frost, once the soil has warmed, and marigolds follow that pattern.
Find your average last frost from the National Weather Service or your county extension office, and treat it as an average, not a promise. For example, if your last spring frost usually falls around the start of May, you might plan to sow or transplant a week or two later and watch the forecast for cold nights.
Garden centers often sell marigold plants before it is safe to put them out. Hold plants in a sheltered spot and cover or bring them in if a cold night is forecast.
Should you direct seed marigolds or start them indoors?
Both work. Direct seed is cheap and easy, and marigold seed germinates readily in warm soil. Indoor starts give earlier bloom and are useful in short seasons. Start seed indoors a few weeks before you plan to transplant, using the timing on the seed packet counted back from your frost date.
Seedlings grown indoors should be hardened off over several days. Plant them at the same depth they grew in the tray and water in well. Nursery transplants are another option and often come in flower already.
- Check the packet for days to bloom.
- Harden off seedlings for several days.
- Plant on a cloudy day or in the evening to reduce stress.
- Water well after planting.
How deep and how far apart should you plant them?
Cover seed lightly with fine soil, following the depth on your seed packet. Spacing depends on the type. Compact French types need less room, and tall African types need more. Check the packet or plant tag and allow for full size.
Thinning is worthwhile. Crowded marigolds hold moisture around their stems and are more prone to disease, and plants with room branch and bloom more heavily.
- Thin seedlings once they have true leaves.
- Keep soil evenly moist until plants are established.
- Allow extra room for tall types.
- Leave space between rows for air movement.
What site and soil do marigolds like?
Full sun and well-drained soil give the most flowers. Marigolds tolerate ordinary and poor soil, and too much fertilizer produces leaves at the expense of blooms. A soil test and local recommendations guide any additions, and nutrient management rules vary by state.
Water at the base and avoid wetting foliage in the evening. Established plants tolerate short dry spells but bloom best with steady moisture.
Mulch lightly once plants are established to hold moisture and reduce weeds, keeping mulch back from stems.
How do you keep marigolds blooming?
Remove spent flowers regularly, which prompts new buds. In midsummer, shear back leggy plants by a third and water well to encourage a fresh flush. A second sowing in early summer gives you plants that bloom as the first batch declines.
Counting back from your first fall frost using the days to bloom on the seed packet tells you the last practical sowing date. Mark that on your calendar.
Compact types often bloom earlier than tall types, so mixing them in a planting spreads the flowering window.
What pests and diseases affect marigolds?
Spider mites in hot, dry weather, slugs on young plants and fungal leaf problems in humid weather are the usual issues. Spacing, morning watering and clean-up reduce them. Ask your extension office to identify a problem before treating it.
If you consider a pesticide, the label is the law, pre-harvest intervals apply for edible plants and applicator licensing varies by state. Marigolds attract pollinators and beneficial insects, so protect them.
- Space plants for air movement.
- Water at the base in the morning.
- Remove damaged leaves promptly.
- Ask extension to identify problems before treating.
How do you plan a marigold calendar?
Write down your average last frost, a target sowing or transplant week after it, a second sowing a few weeks later and a last sowing date counted back from your first fall frost. Add a reminder to shear in midsummer.
Note which types and sowing dates did best. After a season or two you will have a calendar that fits your garden.
- Note your last frost date.
- Mark sowing and transplant weeks.
- Mark a midsummer shearing date.
- Record what bloomed best.
Sources and further reading
Last reviewed: November 2026. Educational information, ranges only. Confirm timing with your county extension office.