When to Plant Zinnia Seeds in Texas for Beautiful Blooms

Written by

William Golder


Dorian Goodwin

when to plant zinnia seeds in texas

Zinnias grow well under hardiness zone 6 to 10 of the Lone Star state, as they’re native to the hot climate of Mexico.

If you’re wondering when to plant zinnia seeds in Texas, March to late September is the general gardening schedule, though variations exist depending on the region you’re in.

Read further below to learn how to cultivate these plants.

Best Time to Plant Zinnia Seeds in Texas

1. Outdoor planting


As zinnias do not grow well under frost, it is essential to sow zinnia seeds under warm weather.

In the spring, wait until temperatures average 50℉ at the minimum before planting these flowers outdoors.

Typically, this would be one to two weeks after the last frost, which falls within March in central Texas, April in northwestern TX, and January to February in southern parts of the state.

You can look up the freeze estimate of your location for accuracy. For example, the final spring frost in Houston is on February 18, so people here can grow zinnia from seeds on February 25 or March 3.

2. Indoor planting


Those who prefer a head start in their planting season can start seeds indoors if they want—four to six weeks before ice and snow disappear. The seedlings in pots will be transplantable once they are 2.5 inches tall and the weather is frost-free.

It’s important to note, however, that zinnias do not like being disturbed, so it’s better if you direct-sow them outdoors or harden the plants off for a week before relocating them.

3. Latest planting time possible

In case you’re wondering how late can you plant zinnias:

  • Look up the first frost where you live and count backward 60 to 70 days from it.
  • The result will be the latest zinnia planting time.

Because Texas welcomes freezing weather around October 16 to December 31, the final month for gardening will be August to October. In very warm regions of the state where frost is rare, one can plant zinnias pretty much all year.

Tips for Successful Zinnia Cultivation in Texas


1. Find these Texas zinnia seeds

Some varieties of zinnias that grow well in Texas are:

  • Benary’s Giants – These have double blossoms in white, pink, yellow, orange, and many more colors.
  • Magellan zinnias – Six inches-wide flowers that come as a seed mix for various colors of blooms
  • Zahara zinnias – Excellent for indoor planting, resistant to mildew and drought
  • Persian Carpet zinnias – Produce both single and double blooms, suitable for garden borders and dry soil

2. Consider the planting location.

Decide whether you want to plant zinnias in containers or in the ground.

If planting in pots, prepare cell packs and potting soil, then sow seeds at a depth of ½ inch. Zinnias germination time will occur within seven to ten days, provided you keep the soil moist and warm at 65 to 84℉.

As for seeding in-ground, the requirements are similar in that the soil should also be warm and exposed to six hours of full sun per day. Aim for a pH of 5.5 to 7.5, and plant seeds at a depth of ¼ inch.

Other essential care tips to keep in mind are:

  • Space the zinnias six to twenty-four inches apart, or follow the recommendations on your seed package.
  • Adequate spacing and watering at the roots (only when the soil is dry) help prevent powdery mildew.
  • Zinnias will develop well if given a slow-release, balanced fertilizer once a month.
  • It’s beneficial to remove the first blooms in addition to spent flower heads so that zinnias blossom more sustainably.

Can I Plant Zinnias in Shade?

Shade is only acceptable in the afternoon when the weather is hot. If you don’t give zinnias enough sunlight, they will produce smaller flowers and be more susceptible to fungal infections.


We hope this article gave you all the details on when to plant zinnia seeds in Texas. Feel free to share this information with others if you find it helpful.

The good thing about zinnias is that they only take about two months to bloom, and they make for stunning bouquets and cut flowers. You can also save the seeds from these plants for resowing instead of buying them from stores.

Other plants you can grow in Texas, click to know the best time:

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