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InsightHorizon Digest

How do you grow giant zinnia seeds in California

Author

Andrew Mccoy

Updated on March 25, 2026

Sowing: Direct sow in spring; this California Giant zinnia flower seed mix germinates best in warm soil. Plant just below the surface and keep the soil lightly moist until germination, which usually occurs within 7-10 days. Seedlings do not transplant well.

Can you grow zinnias in California?

Zinnias tolerate full sun and hot weather very well, and, best of all, they don’t attract insects. … In our mild Southern California climate, zinnias seeds planted directly into the garden germinate quite quickly. Growing from seed is an easy and economical way to get lots of plants at a bargain price.

How long does it take for Zinnia California Giant to grow?

Zinnias generally take 60 to 70 days from seed to flower (though it depends on conditions and variety). They work great in a flower bouquet!

How do you plant a giant zinnia seed?

Growing Zinnias From Seeds Plant the seeds only about ¼-inch deep. You’ll see seedlings sprout in four to seven days. Once the seedlings reach about three inches tall, thin them so that they’re 6 to 18 inches apart to maximize air circulation, a key to keeping zinnias looking good all season.

What month do you plant zinnia seeds?

Planting: Plant zinnias in spring after all danger of frost has passed, around the same time you’d plant tomatoes. Zinnias are easy to grow directly-seeded into the garden. For sooner blooms, start seeds indoors 4 to 6 weeks before your last frost date.

How big do California Giant zinnias get?

Description: Zinnia elegans. California Giants Mix Zinnia seeds form bushy plants that carry masses of huge, 12-15cm (5-6″) wide, double flowers in brilliant hues of red, yellow, orange, lavender, maroon, violet, and white. Growing to a height of up to 102cm (40″), these plants have a very bold visual appeal.

Should I soak zinnia seeds before planting?

It is recommended that you only soak most seeds for 12 to 24 hours and no more than 48 hours. … After soaking your seeds, they can be planted as directed. The benefit of soaking seeds before planting is that your germination time will be reduced, which means you can have happy, growing plants faster.

Will zinnias come back every year?

Zinnias work year after year. It’s easy to save zinnia seeds. Simply let the flowers dry fully on the stem, then collect the seedheads and lightly crush them in your hand to release next year’s seed crop.

How late can you plant zinnia seeds?

I plan succession plantings commencing in late May and continue through about the first week of July. This guarantees showy blooms through late September. It is not too late to plant a few zinnia seeds for late summer color that will last until the first frost.

Do California Giant zinnias reseed?

Zinnias (Zinnia spp.) reseed easily, creating a cut-and-come-again garden each summer, says the University of Wisconsin Extension. Heirloom varieties, cultivated for more than 50 years, are open pollinated and grow into plants identical to their parents.

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Are California Giant zinnias perennials?

Giant zinnias are sun-loving plants that reach heights of 2.5 to 4 feet. Five-inch blooms with layers of rectangular petals are the defining characteristic of these easy-to-grow annuals.

Can zinnias grow in pots?

Zinnias in pots can look just as lovely, if not more so, than those planted in beds. … Zinnias are colorful additions to any flower garden – they’re great for cutting, they are easy to grow and start from seed – so they make a great choice for container gardening.

Do zinnias grow through mulch?

While zinnias can grow well in average soils, Mbofung-Curtis says they’ll perform better with the help of compost, fertilizer, or mulch. … Zinnia seeds can also be sowed directly into one to two inches of organic mulch that will provide nutrients throughout the season as the mulch breaks down to form compost.”

When should I pinch zinnia seedlings?

The secret to getting the longest stems from your zinnias is pinching them when they are young. Here’s how it’s done: When plants are between 8 to 12 inches (20 to 30 cm) tall, take sharp pruners and snip the top 3 to 4 inches (8 to 10 cm) off the plant, just above a set of leaves.

How do you prepare soil for zinnias?

Zinnias like well-fed soil, so some compost worked into the ground early in the season will give the soil an edge before it’s time to get the zinnia seeds or plants in the ground. Moisture is important in the early weeks, but make sure it doesn’t get soggy. Well-drained soil is a must to prevent problems.

How often should I water zinnia seeds?

Cover the seeds with a quarter-inch of potting soil and pat gently. Mist the bed twice daily until the seeds germinate. * Water zinnias at ground level to prevent fungus. Once they are 3 to 4 inches high, water them deeply a couple of times a week, depending on weather.

Can you direct sow zinnia seeds?

When & How to Plant Zinnia Seeds They are classed as tender annuals and can be directly sown into the garden after all danger of frost is over and daytime temps are at least 50F and above. In cooler climates, start seeds indoors 4 to 6 weeks before your area’s average last-frost date.

Are California Giant zinnias heirloom?

Developed in 1926, Heirloom California Giant Zinnias produce stems as tall as 4 feet with huge 5″ blooms, making this variety ideal for cut flowers! … Plant Zinnia California Giant flower seeds in full sun, in beds and borders for a bright and colorful garden. And then, the more you cut, the more they bloom!

What is a California Giant Zinnia?

California Giants is a variety of Zinnia flower seeds that are ideal for beds and borders. California Giant Zinnias have large, dahlia-type flowers that bloom freely in bright shades of red, pink, orange, yellow and white over a long summer season. Remove faded Zinnia blooms in order to extend growing season!

Do zinnias produce seeds?

Zinnias are among the quickest and easiest flowers from which you can harvest and save seeds. And they produce many seeds per plant, so you shouldn’t have to purchase seeds or nursery plants if you want to continue growing zinnias.

Do zinnia seeds need light to germinate?

Zinnias are very low-maintenance and simply need lots of sun, warmth, and well-drained soil in order to thrive and can be enjoyed from summer until the first heavy frost of fall. … Cover zinnia seeds with just ¼ inch of soil because they need light to germinate. • Keep soil moist as the flowers develop.

Why won't my zinnia seeds germinate?

Weather. Planting zinnias at the wrong time of year can cause the seed or seedling considerable trauma and can prevent germination or the establishment of the plant. Make sure the weather is mild and that the ground is not too cold.

Do zinnia seeds need stratification?

The ancestors of our hybrid garden zinnias (Zinnia spp.) are plants native to Mexico, Central America and South America. They grow in hot climates without cold winters, so seeds don’t need cold treatment to germinate. Rather, they need warm temperatures, plenty of moisture and sunshine to germinate and grow well.

Can zinnia seeds be planted in June?

I commonly plant zinnia seeds in late June or early July for fall blooms. Since the plants grow so quickly in the summer heat, they generally begin to bloom about 6 or 7 weeks after being sowed. … With wildflowers, I try to scatter seed on the ground at the same time that the native ones are setting seed.

Why are my zinnia seedlings dying?

The most common cause of early seedling death is “damping-off,” a fungal disease which affects the new plant stem just at soil level. The stem becomes brown, rots and the little plant topples over and dies. Damping-off fungi are more of a problem in cold soils with poor drainage, and in conjunction with overwatering.

What month do zinnias bloom?

One of the easiest annuals to grow, zinnia flowers bring an explosion of color wherever they go. The show lasts from late spring until the first frost in fall. Butterflies and hummingbirds are attracted to the cheery flowers that bloom in nearly every bright color imaginable.

Do hummingbirds like zinnias?

Hummingbirds and butterflies are attracted to its showy blooms. Zinnia, one of the most popular annuals, is easy to grow from seed and thrives in zones 2 to 11. Hummingbirds and other pollinators love the bright blooms, which also make for great cut flowers.

What grows well with zinnias?

  • 1 – Vegetable Garden. The zinnia is by far one of the best companions for your vegetable garden. …
  • 2 – The Purple Fountain Grass. …
  • 3 – Mealy Cup Sage. …
  • 4 – The China Aster. …
  • 5 – The Dahlia. …
  • 6 – The Toothpick Weed.

Do deer eat zinnias?

Deer can eat zinnia flowers if they cannot find other palatable sources. They will also nibble on those flowers on occasion when scouting. To ensure deer do not cause damage to your treasured flowers, use deer deterrents like repellents to keep them out.

How do you know if zinnia seeds are good?

How can you tell if a green zinnia seed is viable? To find out if a green zinnia seed is viable, first pinch the seed between your finger and thumbnail. If it feels hard, you may have a viable seed.

Do zinnias need deep soil?

Ideally, you should be keeping the soil moist to depths of at least 6 inches. This is especially important for young plants. Established zinnias are more tolerant of dry soil. But either way, it’s best to keep the soil moist for continued success.