For a large percentage of people, their first experience with gardening is growing marigolds (Tagetes spp.). These plants are incredibly easy to grow, have an exceptionally long bloom time, and are highly beneficial to the garden. But when do marigolds bloom?
Some of the most popular species include the following:
- African marigold (Tagetes erecta, also called Mexican marigold or American marigold),
- French marigold (Tagetes patula)
- Mexican mint marigold (Tagetes lucida, often just called Mexican marigold)
- Signet marigold (Tagetes tenuifolia)
- Common marigold (Calendula officinalis, sometimes also called pot marigolds)
But with over 50 species and numerous cultivars to choose from, you might be worried about finding a species that blooms at a specific time of year to match your other plants.
When Do Marigolds Bloom?
It might come as some surprise to find that all true marigolds bloom around the same time and last about as long as each other.
However, exactly when the plants bloom and how long can be influenced by how you care for them.
From Seed To Bloom
Marigold seeds take between 7 and 14 days to germinate when kept in constant soil temperatures of 70° to 75° degrees Fahrenheit but may take longer in cooler soil conditions.
Humidity, light levels, and soil moisture can also slightly affect how quickly the seeds germinate.
The wait from the moment you plant marigolds until the time they bloom varies a bit from one species to another, generally lasting from a mere 8 weeks to around 3 1/2 months.
Note that French marigolds grow slightly faster than other marigold varieties, while signets grow slightly slower.
Timing is often everything for these plants, and starting them off early indoors can often result in earlier bloom times.
For many species, deadheading can help extend how long your marigold flowers for.
Indoor marigolds may also be convinced to bloom for longer periods due to their ability to control their environment.
Choosing Marigolds By Feature And Bloom Time
While marigold plants tend to have similar bloom times, that doesn’t mean all marigold blooms are equal.
Here are the key differences between the major types:
- African marigolds grow up to 2′ feet tall with either single or double hemispherical blooms in orange, red, or yellow appearing throughout summer into early fall.
- French marigolds reach up to 3′ feet tall with single or double blooms of often bicolor orange, red, and yellow.
- Mexican marigolds are another summer to early fall bloomer but have clusters of small yellow flowers.
- Signet marigolds are dwarves with five ray florets of orange to yellow hues and bloom from midsummer into fall, sometimes surviving the first minor frosts.
- Triploid marigolds (Tagetes patula x erecta ‘Triploid’) are a cross of the African and French marigolds with a 12″ inch height and 2 1/2″ inch wide blooms, yet can bloom from late spring well into fall due to being completely sterile.
Brief Blooming Timeline
For a quick reference, here’s a brief recap of your marigold’s growth stages.
Any delays in these phases can signal that something’s gone wrong.
- Planting Time – This is either up to 8 weeks before the final frost when starting indoors or after the final frost outdoors.
- 7 to 14 days after planting – Your seeds should be germinating
- 2 to 3 1/2 months after planting – The first blooms should be appearing
Remember that the planting time will also affect how early and long your marigolds bloom.
Why Hasn’t My Marigold Bloomed Yet?
So what happens if your marigolds aren’t blooming when they’re supposed to?
Something may have gone wrong with your marigold, so let’s look at some possible culprits.
Disease Or Pest Problems
While rare, marigolds can still suffer from some infestations and are prone to fungal disease – especially fungal or bacterial root rot.
This may cause the plant to lose vital fluids and nutrients, delaying or even preventing blooms from forming.
Avoid leaving your marigold plants in soggy soil for minimal risk of these problems.
All varieties of marigolds can grow in almost any type of soil, but while they can survive in poor soil, signet marigolds will have trouble producing flowers in overly nutrient-rich soil.
Also, remember that marigolds still need some degree of nutrition to bloom, so the ideal soil will have some nutrients, and you may need to fertilize every once in a while.
Remember that too much nitrogen will cause the plant to focus on foliage growth instead of flowering.
As mentioned, this is a key factor in causing root rot.
Marigolds generally have shallow roots, so ensure they have moist soil without going overboard.
The best watering tactic is to use the soak and dry method when you feel dry soil 1/2″ inch down.
Finally, marigolds don’t need to constantly be out in the full sun, but they do like their sunlight. Too much shade can stunt growth or prevent blooms from forming.
However, too many hours of direct sunlight at midday could also harm the plant if you’re in a hotter climate.
To ensure adequate sunlight, give your marigolds direct morning or evening exposure and light afternoon shade, or place them where they’ll receive bright, indirect light.
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