When to plant Marigolds
Calendar windows
Dates shift with your latitude — they are calculated from your local last-spring-frost date, not from a fixed calendar.
At a glance
Killed by any frost — plant out only after the last one.
Practical notes
The most useful companion plant in a vegetable garden: French marigolds suppress root-knot nematodes in the soil and draw hoverflies that clear aphids. Plant them among the tomatoes, not in a separate border.
Knowing when to pick
Deadhead constantly — pinching every faded flower back to a leaf joint keeps a plant blooming from June to the first frost.
Storing the crop
Let two or three heads dry on the plant in autumn and the seed comes free every year. It stays viable for three years.
Crop rotation
Quick and shallow-rooted — good gap-fillers between heavier crops.
Grows well with
Watch for
Full guide: marigolds diseases and pests (3) → with spread routes, compost verdicts and the prevention this list justifies.