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5 Fascinating California Giant Zinnia Facts

If you’re looking for beautiful, low-maintenance, massive blooms to enjoy, look no further than the California Giant Zinnia!

This plant has been specifically bred over years and years to produce some of the largest, most vibrant flowers out there that are guaranteed to bring a smile to your face.

California Giant Zinnia

Read on to find out everything you need to know about the California Giant Zinnia.

Characteristics of the California Giant Zinnia

California Giant Zinnia


These flowers get their names honestly… these blooms are huge! These massive blooms can grow to be up to five inches wide.

The entirety of the plant itself can be quite large, too. While they average around the three-foot tall range, some plants can grow to be four-feet tall.


California Giant Zinnias almost cover every color of the rainbow. These beauties regularly come in pink, orange, red, yellow, purple, and white!

Sometimes, if you’re lucky, you’ll find yourself with blooms that bridge a couple of the more usual colors, like a lighter lavender or deeper maroon.

How to Have Your Own California Giant Zinnia

Giant Zinnia bloom

Whether you choose to grow your own or buy from someone else, here’s how to get some of the gorgeous California Giant Zinnias in your home.

How to Grow a California Giant Zinnia

Thankfully, these flowers are relatively easy to grow! They don’t require a ton of prep, they’re deer-resistant, and the more you cut off the blooms, the more blooms you’ll get.

Here’s everything you need to know about growing your own California Giant Zinnias.


All zinnia varieties do best with well draining soil that’s high in organic compound. If the soil they’re in is compact or wet for too long, they’re prone to rotting.

If you’re planting directly into the ground in your yard, it would be a good idea to till the area really well and then mix in some natural compost. It could be compost that 

When to Plant

California Giant Zinnias need to be planted in the spring. Make sure that the threat of frost is completely gone because they do the best in warmer soil.

Think about it this way— if you’re getting ready to plant your tomatoes, it’s also time to plant your zinnias!

Where to Plant

Unlike some other flower seeds, California Giant Zinnias do best when they’re sowed directly into the ground.

They don’t transplant well, so it is best to not start them inside in trays and then move them out when frost has passed. Simply wait until all of the frost is absolutely gone and put the seeds straight into the ground.

When you’re ready to plant, sow three seeds directly about a quarter of an inch into the ground with 12″ between them. Once the plants grow to be about two inches tall, thin them out to where there is only one plant every 12″.

If you struggle with patience while you’re waiting for your seeds to germinate, you’re going to love California Giant Zinnias! These seeds will germinate in a short 7-10 days.


Before the seeds have germinated and come above the surface, keep the soil moist, but be careful to not overwater it. 

Once they’ve grown and are mature plants, they need to be watered a couple of times a week. The top 6-8 inches of soil need to stay pretty moist to encourage strong root development, which helps in the overall health of your plant.

What watering your mature California Giant Zinnias, make sure that you’re watering at the base of the plant, not from above. That will help prevent many diseases that come when leaves are moist for too long.

If you live in a really dry environment and would like to ensure the soil stays moist enough, you could add a couple of inches of mulch at the base of your plants. It will not only help hold in moisture, but it will also discourage the growth of pesky weeds.


California Giant Zinnias thrive when they’re pruned! In fact, the most blooms you cut off, the more they’ll produce. 

To get a really good start on a large, bushy, productive Zinnia plant, it’s important to trim it really early on. It may feel counterintuitive, but when your plants are somewhere between 8-12 inches, cut off the top of them, right above a full set of leaves.

This is going to tell your plant to start sending up multiple main branches, instead of just a single one. More branches means more flowers!

If you’re cutting blooms off to use as decoration or to give away, cut them off the plant right after they’ll fully opened to maximize the time you’ll be able to enjoy them.

If you’ve decided to leave all the blooms on the plants to enjoy outdoors, it’s still important to trim off dead or dying blooms to encourage more growth. That’s called “deadheading” and is crucial to bloom production.

Where to Buy California Giant Zinnia

Giant Zinnia, yellow

There are many places from where you can purchase your seeds. True Leaf Market and Botanical Interests are our favorites for Zinnias!

The blooms aren’t readily available to be purchased online, but keep an eye out at your local farmers’ markets! 

How to Use California Giant Zinnia

Zinnia bouquet


These plants are such prolific producers of gorgeous blooms, there will be plenty to cut off and share!

Since they come in such a wide range of colors, you can make an entire bouquet with just California Giant Zinnias.

For a budget-friendly gift, save up your glass containers in the kitchen (think pasta sauce, pickles, and salsa jars), soak the label off of them in your sink, and use those as “vases” to share your garden-fresh creations with your friends and family!


Let the blooms you cut off dry completely, gently hit the dried flower to knock the petals and seeds off, let the seeds dry all the way, and then store them to use the next spring!

Eat Them

Also, if you’re extra brave, you can even eat the zinnia blooms! They’re non-toxic to humans, making them totally edible. They’re a bit on the bitter side, but professionals recommend just using the petals to cut down on the bitterness.

Wrapping up the California Giant Zinnia

California Giant Zinnias are a simple, hassle-free, gorgeous addition to any garden! They’ll bring beauty to your yard and provide you with so many blooms that you’ll have plenty to beauty to share with those you love.

Interested in more zinnia content? Visit my zinnia page for more growing tips, care guides, bouquet suggestions, and more!