Zinnias (Zinnia elegans) have been around for a long time and for good reason; their large, long-lasting blooms and care-free growing habits. The layers of colorful petals which make up each bloom are long-lasting when left in the garden or when used as a cut flower. Heat resistant and drought tolerant, zinnias make a perfect addition to an organic garden.
Choose a location that is in full sun and has well draining soil. Work some compost or humus into the soil before planting to ensure soil is fertile and drains efficiently.
Zinnias aren’t heavy feeders, but must have well-draining soil to thrive. Prepare soil by tilling or spading it to the depth of 8-10 inches.
Apply 2-4 inches of compost on top of tilled soil, then lightly work the compost into the soil. The compost will improve soil structure, promote good drainage and provide most of the organic food the plants will need throughout the growing season.
After all danger of frost has past, scatter flower seeds directly into prepared soil and cover them with ¼ inch of potting soil. Water in well. Seeds will germinate in 4-6 days.
Seeds can be started indoors 4-6 weeks before predicted date of last frost in spring. These plants love the heat and young plants will grow slowly in early spring, but once the summer temperatures heat up the air and soil, these flowers will take a growth spurt.
Thin seedlings to 6-12 inches apart to allow for proper air circulation.
Zinnias require minimal care and typically sail through the summer heat without wilting or ceasing flower production. Water them during periods of prolonged drought or if the plants begin to wilt. Deadhead spent blooms to encourage constant blooming.
The compost worked into the soil prior to planting will keep the plants fed all summer, so no other food is needed.
Add a 2-4 inch layer of organic mulch around plants once they are 8-10 inches tall.
Attraction and Prevention
Butterflies and hummingbirds are attracted to colorful zinnias. When zinnias are planted around the base of a birdbath or bird feeder, it will help to create a non-stop bird show throughout the summer.
Zinnias are prone to develop powdery mildew when planted too close together. Prevent this disease by select zinnia varieties that are mildew-resistant, plant flowers in full sun and space them 6-12 inches apart to allow air to circulate around each plant.