Growing Marigolds from Seed and Cross Pollination



How can I prevent my marigolds from cross pollinating with other marigolds of different varieties?  I want to harvest seeds that will grow and look just like their parents.  My yard is really small, so each of my marigolds (they are planted in containers ) are placed just 30 cm away from each other.  We also have a few bees that like to visit the garden.

My favorite type of marigolds are the signets. The signet varieties I currently have in my garden are lemon gem, red gem, tangerine gem and lemon star. It would be so frustrating if the seeds I saved will not grow into the same variety as their parent, because I really like these vareities and plan to give them to friends.



 A critical issue to consider when deciding if it is worthwhile to save seeds is whether your plants are heirloom, open-pollinated plants (i.e., where pollination occurs by wind or insects, not human intervention) or hybrids..  Although many varieties of marigolds are hybrids, the Gem series are open pollinated.


There are numerous marigold varieties. Many of the commonly grown marigolds are varieties of African marigolds (Tagetes erecta)  and French marigolds (Tagetes patula) . Less known are the triploid hybrids and the signet marigolds.

The triploid hybrids (also known as mule marigolds because they are unable to produce viable seed) are crosses between the tall, vigorous African marigolds and the compact, free-flowering French marigolds.

Signet marigolds are quite different from most marigolds. Botanically classified as Tagetes tenuifolia, Signet marigolds are a lesser-known species of marigold belonging to the Asteraceae family. Signet marigold plants are bushy with fine, lacy foliage. The small, single flowers literally cover the plants in summer. Flower colors range from yellow to orange. They are also edible.

Marigolds in the Gem series are cultivars of Tagetes tenuifolia and these seeds are open pollinated. These marigolds have single flowers that are small, measuring a half an inch to an inch wide, in shades of yellow, red, or orange (with cultivar names like “Lemon”, “Tangerine”, “Golden” and “Paprika”) and frilly foliage. These compact plants grow to be 8 to 12 inches tall and bear flowers that are valued for their citrus scent and flavour, making them some of the best edible marigolds.

Hybrid vs open pollinated:

 Open pollinated plants are more genetically diverse as there are no restrictions on the flow of pollen between individuals. These varieties produce seeds true to type if they are allowed to cross-pollinate only with other plants of the same variety. If they cross with other varieties of the same species, their seed will not come true. Although, even plants grown from heirloom seeds will differ somewhat from the parent plant, as the seeds are obtained from open pollination and are not clones of one another. Interestingly, plants grown from heirloom seeds are generally not as predictably “alike” as “first generation” hybrids.

Hybridization:  A hybrid is the result of pollinating one specific variety of a class of plants with the pollen of another genetically different variety of that class. The plants that grow from these seeds (this is called the “first generation”F1 ) are uniform and include traits from each of the parent plants. While hybridization can occur naturally through random crosses, within the seed industry hybridization is a controlled method of pollination in which the pollen of two species or varieties is crossed; where two carefully chosen “parent” plants that produce “offspring” (seeds) are crossed to create a plant with special characteristics, to breed a certain trait.  So, if you save the seed from a hybrid plant (e.g., one of your Gems), this will grow a “second generation” plant that resembles one of the (original) parent plants, but not the “first generation” plant from which you harvested the seeds. When you plant seeds from a hybrid plant, it is not possible to predict what kind of flowers will result. In addition to this uncertainty, consider also that pollen from neighbouring marigolds (not just those in your garden) will likely be carried to yours by the wind and the bees. This will also be a factor in determining what next year’s plants will look like – again, impossible to predict.

Commercially available seed packets will say if they contain “F1” hybrid seeds.  If the  label does not indicate “F1”, you can assume the seeds come from open-pollinated plants. Original seed packet will tell you if the seeds you started with were from open-pollinated or hybrid plants.

The seed produced by F1 plants is genetically unstable and gardeners who use hybrid plant varieties must purchase new seed every year.

Plant breeding is complex, but in general terms, hybrids are created to combine the best characteristics of two different plants in one plant; while open-pollinated plants are grown to preserve the best characteristics of a single plant over time.

The University of Illinois Extension’s Hybrids & Heirlooms  provides good information about what to consider when growing plants from seed.