A Behind-the-Scenes Peek into Growing Zinnias for Seeds

A Behind-the-Scenes Peek into Growing Zinnias for Seeds

Why Zinnias?

Zinnia flowers growing in an open Greenhouse

Zinnias have to be one of THE easiest flowers to grow. Their perfect disc shape fits into any bouquet, and their heads stand tall and strong in the garden.

Heat-tolerant, resilient, and prolific, these foolproof flowers bloom all summer long.

Zinnias come in every color, size, and shape you can think of—ranging from massive double blooms to charming, petite scabiosa types.

I wanted to share a few details about how we grew the flowers and harvested the seeds.

Growing the Flowers

Although zinnia seeds can be directly planted in the ground, I prefer starting them off in a seed tray. This gives me much more control over how many plants I'll have and how closely together everything can be planted if some of the seeds do not germinate.

When growing flowers for seeds, it is recommended to give the plants a bit more space than if growing for cut flowers. We use 9-inch spacing for cut flowers and choose 12-inch spacing for growing flowers for seeds.

We decided to grow the flowers inside an open hoop house, primarily for a little extra heat and cover from rain. Weather in the Pacific Northwest can be unpredictable, and the extra protection gave us a bigger harvest window. The flowers were grown open-pollinated, meaning we did not isolate them in closed rows or hand-pollinate them. However, we made sure not to grow any other zinnias on our property, and the nearest neighboring garden with zinnias of other types was far enough away. This ensures that the flowers only cross-pollinate with each other, and no random colors are introduced into this mix.

Zinnias and celosia grown together in the hoop house

The hoop house was buzzing with pollinators; they absolutely loved it. The bees even built a hive in there.

This mix originally came from Dawn Creek Farm. The colors include pale peach, blush, rose, ombre raspberry, and a few lilacs. We kept it as a mix to further cross and get more interesting color combinations. We hope to separate some of the more interesting colors and shapes next year for isolation.

close up of rose colored cactus zinnias zinnias in different shades of pink large blush zinnia flower heads

Processing Seeds

Weekly, I would scout the hoop house for ripe seed heads, generally when the blooms turn brown. I would also check for ripeness by pulling some of the base petals apart and looking for dark-colored seeds.

examining seed heads

holding a big bin with ripe flower heads

dry seed heads

We cut the ripe seed heads individually from the plant (our 4yo was a big help 😆) and collected them in a big bin. To avoid the collection of moisture from the petals, we trimmed them with scissors close to the base. Then we laid them out in a single layer in a growing tray and put them in our greenhouse.

Once the seed heads were dry, we removed the seeds from the bloom by rubbing on the seed head. This was quite tedious on a large scale, but easy enough for a 2 yo toddler to do.

We were left with a mix of chaff and seeds. Chaff is dry, scale-like plant material, such as the protective seed casings. Not all of the seeds on the flower will be viable (meaning they have not been pollinated and will not sprout). Those and the chaff need to be separated from the viable “good” seeds.

close up of chaff and seeds

To separate the viable seeds from chaff and non-viable seeds, we used our seed cleaner. Our seed cleaning machine uses a combination of shaking and blowing air to separate the good stuff from the rest. 

seed cleaner

If you are planning on doing this at home, you can sort for the viable seeds by hand. Look for a plump seed when looking from the side. When you gently press on the center of the seed, you should be able to feel a firm spot or firmness. If the seed is flat when you look at it from the side, or if it bends easily, it likely is not viable. You can use a kitchen sieve or screen to remove tiny bits. You can also gently blow on the pile, and the light chaff should blow off.

Our cleaned seeds were then sent off to a lab for germination and noxious weed testing. This ensures that our seeds meet the standards for germination and are clean of any invasive species.

All the seeds are meticulously counted by hand and carefully filled into our reusable seed tubes.

As I pack each order, I find myself pondering the color combinations and the beautiful blooms that will grow in your garden :)

We are so excited to share these beautiful zinnias with you and can’t wait to see them grow!

The cool part about Zinnias is that they can be grown in pretty much any climate because they bloom relatively quickly! Start them in the ground or grow seedlings in seed trays before planting out. Pinch and deadhead the flowers, and you will be rewarded with flowers all season long until frost. They look amazing in bouquets and in your landscape and don’t need much room to grow.

zinnia bouquet with a bee

And collecting your seeds is easy and rewarding!

Let’s Grow!


P.S. Read more about how to grow Zinnias here.


Shop Zinnia Seeds 

Leave a comment