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Zinnia Seeds

Growing Zinnias 

Zinnias are hands down one of the easiest and prettiest flower crops you can grow, they are both reliable and very prolific as they are a cut and come again flower so the more you cut them the more flowers they will produce. The colourful tapestry of blooms in a dazzling array of hues and shapes, are captivating gardeners, florists and flower farmers across the globe.  Commercially there are many mixed varieties available but home breeders and flowers farmers are slowly managing to change the tide and bring to market lots more subtle hues and pretty pastels.

Growing Zinnias

Choose the Right Location

Zinnias thrive in full sun, so choose a planting location that receives at least 6 to 8 hours of direct sunlight per day.

Prepare the Soil

Before planting, prepare the soil by incorporating organic matter such as compost to improve fertility and drainage. This provides a nutrient-rich foundation for robust zinnia growth and abundant blooms.

Zinnias can tolerate a wide range of soil types but prefer a slightly acidic to neutral pH (around 6.0 to 7.5)

Planting Zinnia Seeds

Zinnias can be grown from seeds in to cell trays and then transplanted later, or if the weather is warm enough directly sown into the ground. If starting seeds indoors, sow them one or two to  cell  tray filled with seed starting mix about 4 to 6 weeks before the last frost date in your area. Prick out once they have developed their first true leaves and pot on as needed. Harden off and planting in final flowering position after the risk of frost has passed.  If planting seeds directly outdoors, wait until after the last frost date and sow the seeds directly into well-prepared soil. Space seeds according to the specific variety, usually about  20cm apart, depending on the mature size of the plants.

Watering and Care

Keep the soil consistently moist but not waterlogged, especially during the germination and seedling stages. Once established, zinnias are relatively drought-tolerant and only require supplemental watering during prolonged dry periods. Avoid overhead watering though , as wet foliage can increase the risk of fungal diseases.


Zinnias are moderate feeders and will benefit from  the addition of a  general-purpose fertilizer with equal amounts of nitrogen, phosphorous, and potassium incorporated into the soil at the time of planting. After planting, zinnias should be fertilized monthly using a fertilizer with a higher phosphorous than nitrogen content to promote new blooms.

Zinnia Seeds
Zinnias Seeds


The secret to a prolific Zinnia grow is  pinching. This need to be done when they are young to encourage branching. Pinch them back to around 10cm  tall just above a set of leaves. This will give enough stem for then to send out shoots for a bushier plant .For garden borders pinch off spent flowers (deadheading) regularly to encourage continuous blooming and prevent seed formation.


Plants may get tall and flop over which means that they have no value for cut flowers.  Stake them well with canes or netting to ensure they grow tall and straight. 


Powderly Milder can be a problem - provide good airflow - space further apart of you have problems with this and avoid any stress such as drought .

Harvesting Zinnias

To harvest, cut the stems just above a set of leaves or lateral branch nodes using clean, sharp scissors or pruners and place straight into water.  Do not put them in the the cooler as they don't like the cold 

Pick them when ripe or they will wilt,  use the "wiggle test"  to see if they are ready. Hold the stem about 20 cm down from the flower head and gently shake. If the stem is droopy or it bends, it is too soon to be cut. If the stem is stiff and remains erect, it is ready for  harvesting.

Zinnias are dirty flowers so they will discolour the water in the vase- add a drop of bleach to the water to prevent this. 

They will last 7- 10 days in the vase 

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