How to Grow Marigold Indoors

How to Grow Marigold Indoors

Jun 01, 2021Danah Fabian

Marigolds are known as the flower of the dead in pre-Hispanic Mexico and are still regarded as an important symbol used during Day of the Dead festivities!

 

Timing

Sprouts in 1-2 weeks. Harvest from Month 2+ on.


Part sun

Equivalent of 5+ hours of direct sun [DLI of 15+ mol/m²/day].

Care

Beginner friendly. You’ll sprout, thin, and deadhead.

 

Best Marigold plant varieties to grow indoors.

Most Marigold plant varieties can be grown indoors, just look out for African varieties because these grow up to 2 ft. tall. You can search for a dwarf version, instead. Below are our most recommended varieties for growing marigolds indoors:

French

Produces beautiful orange, red and yellow flowers that are edible, too! Add the leaves to salads and desserts, cooked in egg or rice dishes, or to add flavor to soups.

Urban Leaf

Signet

Can be used for culinary purposes, just make sure to remove them once they are in full bloom. Its flowers also help keep mosquitoes away.

Amazon

Triploid hybrid

They are crosses between the African marigolds and the French marigolds. Triploid hybrid marigolds are unable to set seed.

Harris Seeds

Dwarf African

The perfect choice for beds and borders. Superb for baskets, containers, and window boxes. Wonderful for combination plantings.

Amazon

 

Best Setup for Marigold Plants

You’ll need:

Planter: 

Ceramic Self Watering Planter (preferred) or pot that is at least 4″ / 1 pint.

Soil: 

Standard Potting Mix

Plant Food:

At the start: Balanced Blend. This should be equal parts nitrogen, phosphorus, and potassium (with NPK numbers like 10-10-10). 

Ongoing: Vegetable Blend. This should be high in phosphorus and low in nitrogen (with NPK numbers like 4-10-6).

Grow Light:

A strong grow light that can give the equivalent of 5+ hours of direct sun [DLI of 15+ mol/m²/day].

Jump to: Our product recommendations

Preparing your Planter & Watering Schedule for Marigold

Marigold plants do well in moist soil conditions. If the soil dries out completely the roots will die back and it will be tough for the plant to recover. On the other hand, if the roots are exposed to standing water for too long, they can rot.

A Ceramic Self Watering Planter filled with a standard potting mix self-regulates to keep the soil at consistent moisture for your plant to thrive (and no watering guesswork for you). 

To set one up:

  1. Fill up the planter with dry soil from the bag, gently tamping down the top.
  2. Dump the soil into a large mixing bowl and add water until the soil is moist, but not sopping wet (about ½ Cup)
  3. Mix in 1 tablespoon of the Balanced Blend Plant Food.

If you are using a regular pot instead, it should be a little bit bigger (at least 4″ / 1 pint and will need drainage holes to prevent it from being overwatered. Let the top of the soil dry out between watering.

Growing your Marigolds Indoors: Seed vs Cutting vs Nursery Plant

When growing your marigolds indoors, they can be started from seed, propagated from an established plant, or purchased live at many garden centers. We prefer to sprout from seed or propagate from a stem cutting, as it results in plants that are adapted to your growing conditions and limit the chances that you accidentally bring home pests.)

How to Plant Marigold seeds

Marigold grows quickly from the seed. Plant 1 site in a 4″ / 1-pint container. In larger containers, space sites 4″ apart. For each site plant 3 seeds 1/4 inches deep. Keep the soil warm ( 65-90°F, ideally 70°F). Sprouts typically appear in 7 days but can be as quick as 5 days or as long as 10 days depending on your conditions. 

Propagating Marigold: How to Clone from a Stem Cutting

If you’ve already got a Marigold plant you love (or a friend does!) you can easily “clone” it with just sharp scissors and a clean glass of water. First, cut a couple 6” shoots of new growth (avoid anything woody). Next, remove the lower leaves, so the bottom half is just stem. Place in a glass of 3” of water, making sure the cut leaf spots are underwater. Place the glass on a bright windowsill and change the water every few days. In a couple of weeks, roots should emerge and you can transplant them into your container. While using additional rooting hormones won’t hurt, it’s not necessary with Marigold plants. 

  1. Cut 6” section of new growth
  2. Remove leaves halfway and place them in the water on a sunny window sill 
  3. Wait 7 days for a few ½ inch roots to form and carefully transplant into their final container

How to Transplant Marigold

Live starter plants give you a big jump start on your first harvest. When you’re in a garden center – pick the bushiest plant available (tall and lanky ones will be weak growers) and give it a good inspection for pests. Leaves should be dark green without holes, spots, or curled edges. A best practice is to actually “quarantine” your plant for about a week after bringing it home to make sure it’s free and clear of ride-on pests. 

Ensuring it’s pest and disease-free it’s time to transplant your seedling into its final home.

  1. Remove some soil from its final planter – leaving enough space for the bottom of the seedling to be just higher than the soil surface.
  2. Hold on to the base of the stem with one hand, and turn the pot over while gently pulling the seedling. Giving the pot a few squeezes can help dislodge it.  
  3. Place in its final container and fill around it with soil so that it’s tight, but not compacted.  

Where to grow your Marigold plants

Like all edible plants, Marigold plants need lots of light to grow and develop good flavor. Sunlight is excellent for plant growth (and free!) and you might be lucky enough to have a spot that’s got the 5+ hours of direct sun they need. Even with a bright window, it’s unlikely that you’ll have enough natural light in the winter so we recommend a grow light for anyone who wants a constant supply of flavorful produce. For an introduction to grow lights, head over to our post on grow lights for indoor gardeners. We’ve also got a buying guide for screw in types, but to keep things simple in this guide, we’ll just provide directions for the 24W Screw in Bulb by Sansi, which we think is a good middle-of-the-road option.

How bright should your grow light be? 

Marigold plants need the equivalent of 5+ hours of direct sunlight [DLI of 15+ mol/m²/day] to grow their best. In order to provide an equivalent amount with a grow light, it needs to be pretty bright! The 24W Sansi bulb should be placed 6 inches away from the top of the plant. This will give your PPFD (the standard measure of brightness) of 500 μmol/m²/s.

How many hours per day do your Marigold plants need under a grow light?

Marigold plants are known as “short-day,” meaning they’ll develop faster if they sense over 12 hours of darkness. We want them to progress into flowering as soon as possible, so we recommend setting up a timer to leave it on for only 10 hours per day. This also makes it easy for you to have your own marigold plant indoors.

Marigold Plants Grow Faster in Warmer Temps

Marigold plants are called “warm-weather crops” and will speed up their metabolism when temperatures are warmer. On the other hand, if things get too hot they’ll wilt and become prone to disease. Ideal temperatures are around 65°F but anything between 50 and 70°F grows well.

Week 1-2: Check for Sprouts

You could see seedlings in as little as 5 days (though 7 days is more typical). If it’s been 10 days and you still don’t have any sprouts, it’s likely that your setup is too cold.

Week 3: Thin Your Seedlings

Thin your planter to only have 1 seedling per site –  leaving the largest plant. If you are using the reccomended planter (at least 4″ / 1 pint) this will mean you’ve got 1 plant after thinning.  By getting rid of the smaller seedlings, you’re allowing the biggest and strongest one to flourish by reducing its competition for water, food, and space. 

If your seedlings are under 1 inch, stretching out, or folding over, it’s likely that they don’t have quite enough light.

Month 2+: How to Harvest Marigold

Pick flowers right as they open to encourage more flowers to grow. If you let flowers go to seed on the plant it will start to end their life cycle so you should “deadhead” (remove the old flowers) to prolong the flowering season. If you fall behind, you can cut the plant by one-third which produces a second flush of leaves and flowers.

Year 1: End of Life

You can prolong your marigold’s life by pruning it and removing flowers before they have a chance to go to seed, but eventually, it will die. At this time is best to clear the plant and start over.

Shop This Blog

The right supplies can take the guesswork out of caring for your plants – and turn care from a daily to weekly routine. Through our grow tests, we’ve found these products to produce the best indoor Marigold (and also have simple maintenance).  Plants are adaptable and can grow in many different conditions, so they are by no means necessary if you already have other supplies.

Best Containers for Marigold: Ceramic Self Watering Planters

Plants thrive on consistent moisture but can suffer if they’re waterlogged. A semi-porous ceramic self regulates ideal conditions. Our favorite is the COSWIP planter. Runner up is XS Self Watering Planter by Wet Pot.

Best Soil for Marigold: Standard Potting Mix

Marigold likes a rich and moist root zone – so you are best off with a standard potting mix – we like this Organic Mix by Espoma

Best Nutrients for Marigold: Balanced Blend followed by Vegetable Blend

Marigold likes to start with nutrients that are equal parts nitrogen, phosphorus, and potassium (with NPK numbers like 10-10-10). For this Balanced Blend we recommend: Dr Earth All Purpose

Once they are growing, it’s better to use plant food that is high in phosphorus and low in nitrogen (with NPK numbers like 4-10-6). For this Vegetable Blend, we recommend: Joyful Dirt Tomato & Herb

Best Light for Marigold: DIY or Soltech

There is a very small chance that you have the bright windows needed to grow these without a grow light. If you are looking for a higher-end option – we love the Aspect Light by Soltech. For a more affordable option, a DIY setup using a 24W Screw-in Bulb by Sansi with a Clamp Light and Mechanical Timer works well too.  Check out our complete guide on a DIY setup for less than $40 or our buying guide for screw in bulbs.



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