When to Plant Zinnia Seeds
Zinnias are best started directly outdoors in locations where spring warms up early. Keep in mind that Zinnias are native to Mexico, where they have become accustomed to long, hot summers. 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. Harden off the plants by vacationing trays outside for a few hours per day before planting them in your garden.
Where to Plant Zinnia Seeds
Choose a spot that has full sun. Zinnias can thrive in a wide array of well-draining soil conditions.
How to Plant Zinnia Seeds
Turn over the soil in the area you want to plant your zinnias and work in 2 or 3 inches of compost or peat moss to help improve soil fertility and drainage. Plant the seeds only about ¼” – ½” deep and you should see seedlings sprout in four to seven days. Once the seedlings reach about 3” tall, thin them to maximize air circulation, and prevent powdery mildew. The dwarf varieties, reaching a height of 1 to 1 ½ feet, should be planted or thinned to about 9” apart, while the taller 3-feet varieties should be spaced about 1 foot apart. If starting your zinnias indoors, fill up your pots with organic potting mix. Saturate the potting mix with water and then place two zinnia seeds into each planting cell or pot. Press into the soil for good seed-to-soil contact and then cover with approximately ½” of the potting mix. Place your zinnias in an area that will receive plenty of warmth (65-70F) and light. Keep your zinnia seeds moistened, checking on them every day or two. Expect to see germination in about 7 to 10 days. Once your seedlings reach about 2 ½ – 3” tall, they are ready to be transplanted outdoors. Zinnias may be transplanted with ease, as it is possible to move the plants when they are in full flower! Although they thrive best in full sun, they will also endure partial shade.
How to Care for Zinnias
Water the area of your zinnia plants carefully, do not get the stems or leaves wet since zinnias are prone to mildew. Keep your zinnia garden lightly moistened, and let the area dry out between watering. The beauty of zinnias is that you can spend your attention elsewhere while they bloom profusely summer to autumn.
