Zinnia

When to Start

Spring: Start indoors 6-8 weeks before the last frost. (Mid-Feb – Mid-Mar for Jefferson, GA)

Direct sow: After outdoor temps are above 50 F and all danger of frost has passed. (May 1 for Jefferson, GA)

Start Indoors for Trap Cropping. You need to start soon enough so that the plant is blooming at the time the pests you are trying to contain arrive.

How to Start

For later transplants, start zinnias indoors 6-8 weeks before the last frost. Sow 1/4 to 1/2 inch deep into seed cells and place under grow lights. They are large enough for transplant when they are 2.5 – 3 inches tall. Once they have grown enough, harden the seedlings off. Then transplant them into full sun beds. Or you can direct sow once the danger of frost has passed and outside daytime temperatures are 50 F or higher.

Care

Powdery mildew and other diseases can attack zinnia flowers that are planted too close together or that remain wet from overhead watering. Space the seeds 4-6 inches apart for smaller varieties and 12 inches apart for taller varieties. This allows for adequate air circulation around the plants as they grow. By watering at the base of the plant with soaker hoses, the leaves will stay dry which will also help prevent these fungal problems.

They are heat-loving plants and do very well in areas with long hot summers. Zinnia plants benefit from deadheading and flower removal until you are ready for them to go to seed.

Planting with a purpose

Zinnias are aesthetically pleasing. They attract numerous butterflies and other pollinators. They make both a good trap crop and a companion plant.

Companion Planting

When using zinnias as a companion plant, intermix them with vegetables. Zinnias attract the hoverfly, which will eat aphids. They also attract parasitic wasps, which will eat tomato hornworms (and many other pests) as well as, numerous other predators. For more information watch “Companion Planting” (Link below).

Trap Cropping

When used as a trap crop, these flowers can protect other crops that Japanese beetles will destroy. They may not look as pretty after the beetles get done with them, but that just means they are doing their job! For more information follow the steps in “Trap Cropping” (Link below).

• Edible flowers
• Companion plant
• Trap crop
• Attracts pollinators and hummingbirds
• Good cut flowers
• Deer resistant
• Easy maintenance
• Container friendly

• Burpee’s Big Tetra: Heirloom. Blooms come in a colorful spectrum of 6″ dahlia-flowered blossoms, in bold oranges, yellows, reds, and whites. Glorious as cut flowers. A magnet for pollinators. Heat-loving.
• Bureeana Giants Mix: The 2′ plants are soon massed with 6″ blooms in a wide range of bold colors.
• California Giant: Heirloom. Developed in 1926. Plants produce stems as tall as 4 feet with huge 5″ blooms, making this variety ideal for cut flowers! The shape of the flower is a bit more open than the Dahlia Flowered variety, with petals rounded on the end.
• Candy Cane: It has bright pink, rose, and cherry stripes on white and sometimes gold blossoms flecked orange scarlet. The blooms are 4” across and loved by pollinators. 
• Cut & Come Again: Plants have long-stemmed flowers in a blend of pink, bright scarlet, yellow, salmon, white and more. The more you cut, the more they bloom. They will bloom until frost. Heat-loving and good cut flowers. 
• Envy: This green zinnia has  3″ double and semi-double blooms.
• Forecast Mixed: It is a mildew resistance variety. It bears purple, pink, orange, salmon, yellow, or cream petals that are 2-3″ across. 
• Fruit Smoothie: Blooms are 3” across and come orange and purple. 
• Giant Flowered: Huge, 5″ doubles, on sturdy, bushy plants. 
• Pinwheel Mix: It is mildew-resistant and compact. 
• Pop Art Red & Yellow: Large 2-3″ golden-yellow fully double blooms with radiant red streaks.
• Purple Prince: Heirloom. Radiant fuchsia blossoms. Stunning in mass plantings and mixed with other bright colors like greens and oranges! 
• Queeny Lemon Peach: Heirloom. Lemon-colored petals reverse fade to a soft coral for a stunning transition. Ideal for cut flowers.
• State Fair Mix: Heirloom. Blooms come in many colors on tall, robust stems. They are perfect for cutting or enjoying in a container or garden bed.
• Zinderella Lilac:​ Double flowers. bloom from July through September.
• Zinderella Peach: Heirloom. Flowers come in striking shades; surprising, hard-to-come-by patterns. Blooms are fully-double, semi-double, and single 2-2½ inch crested blooms with creamy centers and soulful dark eyes. 

The petals are edible but slightly bitter and best used as a decoration on cakes or as a garnish on salads.

If you’re having trouble with Japanese beetles, plant zinnias near the problem area. 

Zinnias are a good companion plant that will attract predators to help with pests. 

For more details on using zinnias for pest control see Pest Management. 

Sources:

Edible Flowers: How, Why, and When We Eat Flowers by Monica Nelson

Gardenguides.com

Starting & Saving Seeds by Julie Thompson-Adolf