How To Grow Zinnia Flowers From Seed

Gardeners across the world have fallen in love with Zinnia flowers and the good news is they are really easy to grow from seed!

Sowing + Germination Tips:

• Zinnias are very frost sensitive, so wait until the last frost has passed before planting. 

• Zinnias don't like being transplanted, so if you live in a warmer climate sow zinnia seeds direct where they will grow. The seeds are very quick to germinate and should germinate in 3 - 7 days when the soil temp is around 21 - 29 degrees. If direct sowing the seeds, make sure the area if protected from wildlife, birds and unwanted slugs that may dig up the seeds or eat the baby seedlings.  

• If you live in a cooler climate, you will need to start seeds in a greenhouse environment. Raising the seedlings in single celled trays at around 21-29 degrees (a heat mat can help maintain an accurate temp) may help prevent the roots becoming root bound, reducing transplant shock when transferring the seedlings into the garden. A stressful event for the seedling can cause double-flowering varieties to produce single blooms.

Planting + Harvesting Tips:

• After six weeks of growth in the greenhouse, the seedlings are ready to venture into the outside world. Start by letting them spend 1 hour a day outside and work up to 5 hours over a week. This is called 'hardening off'.

• Pinch out your zinnia seedlings when they are 30cm tall (3 true sets of leaves). Pinching out means taking the top 10cm off your seedling to remove the first centre bud. This will encourage stronger, taller stems, branching and more flowers!

• Zinnias are heat lovers, so plant in full sun with good air circulation. This will prevent them from getting powdery mildew. 

• Space between 15 - 30cm apart (depending on the variety) and rows 30 - 45cm apart. 

• Taller Zinnia varieties will require support. Use flower netting staked 30cm above the ground to give them the support they need. More on supporting your flowers here

• When established, water the base of the plant and try not to water the leaves, a drip irrigation system would be ideal. They don't like to be water logged.

• Zinnias are annuals, so when flowering, deadheading any flowers that have died will encourage more to grow! 

• Harvest your Zinnia blooms when the stems are stiff. You can do the "wiggle" test, if you hold the stem about 20cm below the flower and give it a little wiggle, if the stem is floppy it's not ready to harvest. If it is stiff then it's ready!

• Zinnias take around 90 days from seed to bloom.

• The blooms will last around 7 days in a vase, zinnias are known as a "dirty" flower, so to extend the vase life change the water often.

• Please note that in warmer climates, Zinnias are more likely to produce more single rather than double blooms.  

Our most loved varieties:

We are absolutely over the moon to offer Australian gardeners the very special Floret Original Zinnia seeds. We have have worked alongside Floret to bring these magical seeds into Australia. Erin Benzakein spent 7 long years breeding these unique varieties, and these stunning blooms are truly unique to Floret. 

Queeny Series including the gorgeous Queeny Lime with Blush, Queeny Red with Lime, and Queeny Lemon Peach. The Zinnia Queeny series are mostly double and semi double blooms with a small percentage of singles.

Zinderella/Cresto crested double, semi double, and some single flowers.

Oklahoma are a smaller bloom with a very high percent of fully doubles, perfect for weddings and event work. Oklahoma have a high disease resistance. 

Benary's Giant as the name suggests, large fully double blooms make premium cut flower.

Shop our Zinnia Flower Seed collection here.

Frequently asked questions about growing Zinnia flowers: