Problems Planting Zinnias

Seeds

• Planting zinnia seeds that have been improperly stored or harvested will diminish your successful germination of the seeds to 50% or less germinating. Planting zinnia seeds that have been harvested properly in the last year, rather than old seeds that have been stored for several years, increases the number of seeds that will successfully germinate. Test your stored zinnia seeds germination ability by thoroughly wetting several layers of paper towels, then place some of the stored zinnia seeds between the wet towels. Check every few days for germination. After seven to 10 days if only 50 to 60% of the seeds have germinated, sow twice the amount of stored zinnia seeds in your garden, then discard the remaining old seeds. Sowing your zinnia seeds too deep will also decrease the level of germination. Plant the seeds less than 1/2 inch deep, in a location with fertile soil that receives full sun all or most of the day, will increase your planting success of any variety of zinnia seeds.

Soil

• Cooler soil temperatures will delay zinnia seed germination and many seeds may not germinate at all. The soil you plant your zinnia seeds in needs to have naturally warmed to around 50 degrees F. Although established zinnia plants can grow in poor soil, planting zinnia seeds and bedding plants in rich, loamy well-draining soil will alleviate problems. Soil that remains water logged will rot newly planted zinnia seeds, while planting the seeds in soil that dries out too quickly will delay or stop germination of zinnia seeds. Supplement the soil with 2 to 4 inches of well-rotted manure, compost or organic material, worked into the soil to a depth of 10 to 12 inches a week or so before planting your zinnia seeds to improve the plants growth, health and alleviate drainage and nutritional problems.

Water

• Mature, established zinnia plants can tolerate periods of drought and limited water, but when you initially plant zinnias, the soil needs to stay evenly moist, but not saturated or soggy, which can impede germination or root development. Over watering causes more problems, like root rot, bacteria infection and disease, than under watering zinnia plants. Newly planted zinnia bedding plants will suffer if under watered before the roots have an opportunity to spread and become established in the soil. If you find your zinnia plant stems or leaves wilting, examine the moisture level of the soil. You will discover the soil has been either too wet or too dry for an extended period of time, thus causing the wilt. Correct the problem by stopping watering the area until the soil has dried several inches below ground for soggy soil, or deeply water the zinnia growing area immediately for dry soil.

Disease

• Planting and growing your zinnia plants too close together, minimizing air circulation around the plants, can quickly cause problems of bacteria infection, fungus and powdery mildew. If you have sown seeds, once the seedlings have grow 3 to 4 inches, thin the plants to space them 6 to 10 inches apart, depending on the size at maturity of the plant. More space between plants is required the larger the mature zinnia plant will be. Overhead watering will also promote these diseases, so it is recommended to bottom water zinnia plants.