Updated at: 27-03-2023 - By: Sienna Lewis

If you’re wondering, “When can I start growing marigold seeds in a greenhouse?” you should probably start with the fundamentals. These plant-growing seeds are a great addition to anyone’s garden or greenhouse.

What Are American Marigold Seeds?

The American marigold is a tall plant, reaching a maximum height of 36 inches, though selective breeding has resulted in shorter varieties. In spite of their origin in Mexico, these annuals can be found all over the world, including in Africa and the Americas. The most audacious and voluminous of these marigolds are the flashy annuals.

However, the breeding of American marigolds might be required to achieve this height. However, their orange, gold, and yellow flowers are enormous and fully double.

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The American marigold prefers full sun and well-drained, moist soil, but can thrive in drier environments if necessary. Having them planted outside as soon as the threat of frost has passed is essential. The recommended distance between each seedling is 10 to 18 inches.

How Soon Can You Start Seeds In A Greenhouse?

If you start these seeds indoors before it’s time to transplant them outside, your seedlings may be too tall for their containers when you’re ready to plant them. If it’s too late, harvesting could be postponed. Be sure to sow heat-loving seeds, and get your transplants outside before the weather gets too chilly.

Seeds should be started in moist peat pots or flower pots. Many gardening manuals recommend following the planting instructions on the back of the seed packets. Only two or three seeds should be planted at a depth of half an inch. Make sure the seeds are buried and misted with water.

When Should I Start Seeds In Massachusetts?

Massachusetts, known as “The Bay State,” has plenty of fertile soil, but there are also many places to buy greenhouse seeds within the state. The last day of frost typically occurs in various parts of the state around May 15th.

Determine how many weeks have passed since you planted each vegetable in your garden. You can use this information to determine when you should start the seeds indoors. The seeds for the root vegetables need to be planted outside.

This timeframe is relative to the seeds you have available. The following are the steps you need to take to start growing American marigold seeds.

  • Wet the potting soil down a little bit. Soak the potting soil in a large bucket of water. Shake it up.
  • Fill the containers about halfway before leveling them off with soil. Try not to cram this in there.
  • Put larger seeds, like those for a cucumber or muskmelon, into the container.
  • Then, bury three seeds beneath a quarter-inch of potting soil.
  • Peppers and lettuce, both of which start from relatively small seeds, need to be planted in rows and then transplanted or thinned.
  • Soak it lightly with warm water. Keep the plants alive and well-watered.

How Do You Start Seeds In A Small Greenhouse?

Then, as part of the discussion on “When can I start growing American marigold seeds in Massachusetts in a greenhouse?,” it is also important to learn how you can start seeds in a small greenhouse.

Let’s back up a bit; what exactly is a miniature greenhouse? In comparison to other greenhouses on the market, these are quite compact. Mini greenhouses, which can range in size from two to eight square meters, are incredibly useful if you have a small yard or balcony and want to start a garden.

Growing seasons can be prolonged with the help of greenhouses of this type. In most cases, it will shield your seedling from dangerously low temperatures. The greenhouse’s ability to retain heat could also help your soil retain moisture, which would make it less inviting to pests and other animals.

It also moderates the weed’s growth so it doesn’t take over the garden. Greenhouses offer numerous advantages that more than justify their high initial cost.

  • Fill your greenhouse planting tray or pots in accordance with the instructions listed on the potting mix, and then get to work planting your seeds in the small greenhouse, such as your American marigold seeds in Massachusetts. After that, place the tray inside a larger container and fill it with a single inch of lukewarm water.
  • Drain the drip tray’s excess water after 30 minutes, or when the soil’s surface is damp.
  • Following this, plant seeds should be sown in a potting soil mixture at the depth recommended by the manufacturer. Then, scatter your seeds about an inch apart in your flats and trays, planting two seeds in each pot or planting cell. After planting, if the soil is too dry, mist it with water.
  • Cover the tray with the greenhouse’s top. Rotate the greenhouse to a spot that gets between 65 and 75 degrees Fahrenheit of indirect and direct sunlight. The cover needs to be water-repellent so that it can go without being watered until after the seeds have germinated.
  • At this point, once your seeds have begun to sprout, you should prop open your greenhouse cover to allow condensation to dissipate. Your small stick or pencil will come in handy for holding one end of the cover.
  • Once the soil has dried out around your seedlings, you should water them. To prevent fungal disease in your seedlings, water should be poured into the drip tray rather than directly onto the soil. If you want to avoid damaging your seedlings by touching them with plastic, you should take the greenhouse cover off completely before they reach full height.

Time Of The Year To Plant Marigolds

Growing seeds of American marigolds should require knowledge of the appropriate timing. After the last chance of frost in the spring has passed in your area, or when the seeds started indoors begin to grow about eight weeks after the final frost, the farmer may be able to plant marigold seeds directly outdoors.

In soil temperatures as high as 75 degrees Fahrenheit, the seeds could germinate in as little as four to fourteen days. The risk of frost has passed, so you can start transplanting your seedlings. Depending on the temperature, marigolds can bloom anywhere from 45 to 50 days after planting, and they will continue to do so right up until the first frost.

If you liked this post, we have plenty more information on greenhouse gardening basics and advanced techniques. The answer to the question “when can I start growing marigold seeds in a greenhouse?” should be easier to arrive at now.

When Can I Start Growing American Marigold Seeds In Massachusetts In A Greenhouse: Calendar For Planting

Before the last frost date in Massachusetts, you can start your marigold seeds indoors. Timeframes of eight weeks or fifty days are acceptable. The University of Massachusetts at Amherst reports that the last frost date across the majority of the state is typically May 15.

Eight weeks before the last frost date

Earlier, we established that starting American marigold seeds in a greenhouse eight weeks before the last frost is optimal. You can find out when this is by looking up the hardiness zone map for your specific part of Massachusetts. If you plan on planting outdoors, though, you’ll need to wait until after the last frost, which is typically in the spring.

The last frost date for your area should be subtracted from the current date to determine when you should start your seeds indoors. Growing marigolds from seed indoors will allow you to enjoy their bright blooms sooner. The danger of frost has passed, but the seed can be planted outside because the plants only take a short time to go from sprouting to flowering.

It is more prudent for gardeners to use the greenhouse because flowers can be started inside in relative safety. You should keep in mind that the last frost in most of the state of Massachusetts occurs around the 15th of May. For reference, let’s say you want to put marigolds in a greenhouse in a few weeks from now.

Fifty days before the last frost date

Mid-spring planting will go smoothly if you started your marigolds about 50 days before the last frost date. By doing so, you can ensure that your plants reach the proper size without worrying about the effects of the weather in the open. The germination time for seeds is very short.

To prevent this from happening, make sure the plants get at least 6 hours of light every day. Once a second set of leaves has emerged, the seedlings can be thinned. While waiting for the last frost date in the greenhouse, you can plant them in their pot.

Other Considerations For Growing American Marigold In A Greenhouse

The success of your flowers will depend on a number of factors after you’ve figured out when you can plant America marigold seeds in a greenhouse in Massachusetts. The time it takes for seeds to germinate, for instance, can be as short as 14 days. However, indoor temperatures should be between 65 and 75 degrees Fahrenheit, and soil temperatures should be between 70 and 75 degrees Fahrenheit.

A warm and damp flower bed inside the greenhouse is ideal for planting the seeds. The marigolds will bloom 50 days after planting and will continue to do so until frost. Check the pH of the soil and see if it needs any organic amendments before planting. Marigolds should be spaced at 24-inch intervals if they are large, 15-inch intervals if they are medium, and 6-inch intervals if they are small.

When and How to Plant Marigold Seeds | Gardener's Path

What Makes American Marigolds Different From Other Marigolds?

If you compare the planting requirements of American marigolds to those of other varieties, you’ll find that spring is the ideal time to get them in the ground. This is because they take longer to reach full maturity than, say, French marigolds. You can use these tall blooms as planting pockets or to bring color to the garden in front of shrubs.

If you want your beds and borders to stand out, plant some American marigolds in them. In addition, some green thumbs plant American marigolds as a boundary hedge for their herb garden. However, which types of plants are most successful in a garden?

These are some of the most well-liked: Antigua Series, Jubilee Series, and Vanilla. American marigolds from the Gold Coin Series make fantastic hedge plants.

Why Sow Outdoors

Planting seeds outside is less of a hassle than getting them going in a greenhouse. Transplant shock is avoided, fewer resources are used, and fewer steps are required.

Seeds of marigolds can be sown directly into the garden without the need for an indoor seed starting project:

  • Most cultivars of the French marigold (T. patula) and the signet marigold (T. tenuifolia) are among the fastest maturing varieties available.
  • If you can wait for the flowers to bloom, that is.
  • So long as your growing season is sufficiently lengthy.

We should elaborate on that last point. How can you tell if your growing season is lengthy?

A long growing season can be assumed if it is possible to cultivate warm-season crops such as tomatoes, squash, eggplant, and peppers without worrying about early frosts.

If, on the other hand, you have experienced problems with these crops being affected by early frosts in the past, you are probably like me and many other northern and high elevation gardeners who must face the challenges of a short growing season.

Whether or not you have time to sow these annuals outdoors can be determined with more accuracy as follows:

Consider the plant’s required maturation time and the number of days without frost in your region.

Using this tool from the National Gardening Association, you can quickly determine the number of frost-free days you have.

Inputting your zip code will give you the regional average.

Get the number of days to harvest for the plant type you’ve settled on. Typically, this data can be found on the seed packet.

French marigolds (Tagetes patula) typically take 50-60 days to bloom, while Mexican marigolds (T. erecta) take 70-100 days.

Evaluate the time it takes for your plant to mature in relation to the number of days that frost is not expected.

Flowers from a marigold plant that takes 100 days or more to bloom could potentially last you three months, given a growing season of 190 days. To my mind, this is a fantastic offer!

But if your growing season is shorter than mine (about 104 days), you might not see any flowers at all if you plant them outside.

Possibly, at most, you’ll get some buds.

Therefore, the slower maturing varieties should be started indoors if you have a short growing season, and the faster maturing varieties should be considered for direct sowing.

Read this guide to find out when it’s best to plant seeds indoors and when it’s best to plant them outside.

When to Sow Outdoors

Since marigolds are annuals, they are not at all frost hardy and will be severely damaged or killed if frost hits them.

For that reason, these plants exude a scent more associated with summer than spring.

While full-grown marigolds may be able to withstand a light frost, the tender seedlings should not be exposed to the cold.

Direct seeding into garden soil should be done no sooner than two weeks after the average date of the last frost in your area.

That way, the danger of late frosts will have passed by the time your marigold seeds germinate.

How to Sow Outdoors

Pick a spot in the garden that gets at least eight hours of sunlight each day before you start planting.

It’s okay to give these annual flowers a little bit of shade, especially if your summers get very warm. In contrast, flowers grown in full sun will bloom with more vibrant hues.

Keep in mind that marigolds require well-drained soil when deciding where to plant them.

Compost can be used to improve drainage in situations where heavy clay is present. Plant seeds in raised beds instead.

A light soaking with the hose before planting is recommended. This is something I like to do a few hours before planting seeds so that the ground is damp but not soaked.

Gently remove a small amount of soil and use it to conceal the seeds. Gentle patting will firm the soil and help it to settle into a uniform level.

If you don’t want to scatter the entire contents of your seed packet on the ground, pour some into the palm of your dry hand first. These seeds are feathery and delicate, making them simple to plant.

Groups of three or four seeds should be planted in the prepared soil at a distance of 6 to 12 inches apart, depending on the expected spread of the mature plants.

If you’re growing larger varieties, you’ll need to give them more space between themselves. It is recommended to space smaller cultivars 6-8 inches apart and larger ones 10-12 inches.

To plant seeds, press them gently into the soil and then cover them with the soil you pushed to one side, burying them about half an inch deep.

Pat the soil down gently and smooth it out, then water it lightly with a watering can or the gentlest setting on your watering wand.

You must water the seeds every day until they sprout. Watering should be gradually reduced until established plants are receiving about an inch of water per week.

Why Start Indoors

Is it possible that you might be better off not planting the seeds in the ground?

The following are some arguments in favor of starting marigolds indoors:

  • If your growing season is on the short side.
  • To get flowers before the heat of summer sets in.
  • If your region experiences fatal frosts in late spring or early summer.
  • If you are growing a T. erecta cultivar, or any other variety that takes longer to mature.

When to Start Indoors

When starting seeds indoors, you should do so roughly 6-8 weeks before your average last frost date.

If you sow marigold seeds indoors and give them 6-8 weeks to develop, you’ll be rewarded with blooms sooner than if you planted them directly in the garden.

Early maturing varieties will be ready to bloom soon after being transplanted into your garden at the start of your local warm season.

How to Start Indoors

There are only a few things you’ll need to get started growing marigolds from seed indoors.

If you’ve never grown annuals from seed before, you may want to read through our comprehensive guide to starting annuals from seed indoors.

To help you get going, here are some pointers:

  • It’s best to use sterile potting soil or soilless starting mix.
  • Just a couple of seeds should be planted in each cell of the starter tray.
  • As soon as the seedlings reach about 2 inches in height, remove all but the healthiest plant from each cell.
  • Avoid waterlogging and damping off by watering regularly with a spray bottle.
  • If a south-facing window is being used in place of grow lights, the seedlings will need to be turned daily to keep them from leaning in the direction of the light.

Hardening off seedlings outdoors will help them adjust to their new environment before you transplant them.

A protected, wind-free outdoor spot in the shade is the first step.

Over the course of a week, leave them out in the sun and wind for an extra hour or so each day until they are spending the entire day outside in their final planting location.

Put the transplants in a spot that gets full sun and has soil that drains well and water them thoroughly.

For this reason, I prefer to perform transplants in the evening or on overcast days so that the transplants can adjust to their new environment with less stress from the heat. As a bonus, it shields me from the sun.

How To Grow Marigold Flowers For Your Summer Flower Garden

The first week, water it every day. Once plants have become established, water deeply once per week. To prevent your flowers from looking wilted and lifeless, water only at the base of the plant and never directly spray them.

Need some more advice on how to maintain your annual flowers? Check out our full marigold growing manual for more information.

Though I’ve yet to meet a marigold I didn’t like, there are a few varieties that have really piqued my interest, and I’d like to tell you about them.

Each of these suggestions is a variety of the French marigold (T. patula), which matures quickly and is a popular garden plant.

Beautiful flowers can be enjoyed early in the growing season whether you start your seeds indoors in flats or outdoors in the garden.

Queen Sophia

The fiery petals of the All-America Selections Winner ‘Queen Sophia’ are both inviting and captivating.

This French variety has double blooms that are between 2 and 3 inches in diameter, and the petals are a deep orange with yellow edges.

Plants reach a height of 10-12 inches and a width of 8 inches.

In 60 days, “Queen Sophia” will be fully grown.

Seeds of the variety known as “Queen Sophia” are available at Eden Brothers in multiple quantity packs.

Strawberry Blonde

Since most varieties of marigolds come in the standard yellow, red, and orange, it is exciting to come across a rare pink cultivar like ‘Strawberry Blonde.

This variety’s flowers open a deep red, but they gradually change to a warm yellow.

At maturity, the plants will have grown to a height of 8-10 inches and a spread of 6-8 inches.

Between 55 and 70 days, ‘Strawberry Blonde’ can be harvested.

Strawberry Blonde is sold only by Burpee, and only in packs of 50 seeds.


If you can’t make up your mind which kind of marigolds to plant, try a variety.

Double blooms of 2 to 2 1/2 inches in diameter come in a variety of attractive bicolor and solid yellow, orange, and burgundy colors in the ‘Durango’ mix.

A mature plant can grow to a height of 10-12 inches and a width of 9 inches.

The ‘Durango’ mixture of flowers blooms at maturity in 50-60 days.

The ‘Durango’ mix, as well as a wide variety of other ‘Durango’ colors, can be purchased in packs of 1,000 seeds at True Leaf Market.

Turn Seed into ‘Golds

You should now have a good idea of the best way to turn seed into ‘golds, given consideration to the length of your growing season, your chosen varieties, and how quickly you want to enjoy the blooms.

So, gardener, what have you decided? Which comes first, starting seeds indoors or sowing them outside? Perhaps both? What wonderful plants are you cultivating? Post your thoughts in the section below.

And why not check out the next guides to learn more about gardening flowers:


Flowers thrive in the climate and soil of Massachusetts. American marigolds are one of the more common varieties, and seeing them may make you wonder, “When can I start growing American marigold seeds in a greenhouse in Massachusetts?” Either eight weeks or fifty days prior to the last frost date is fine for planting the seeds.

Your ability to predict when frost is likely will be greatly enhanced by your familiarity with the hardiness zone of your region. Despite the fact that the last frost date for the majority of the state is on May 15th, Massachusetts is split between hardiness zones 5 and 7. As a result, double-check your seasons to avoid problems.