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How to Plant Zinnia Seeds

By Gertrude Elizabeth Greene ; Updated September 21, 2017

Zinnias are popular garden plants that produce beautiful, brightly colored flowers. They are known to attract butterflies, and many gardeners plant them for this purpose. Zinnias require rich and well-drained soil, at least half a day of sun and regular water. They will bloom from midsummer to the first frost, and should be planted or transplanted after the last frost date in the spring. The seeds will be more likely to sprout in warm soil.

Planting the Zinnias

Use the yardstick to measure the size of the flowerbed. Plant one zinnia every square foot, approximately.

Determine how many zinnias you want to plant. Procure one small pot for every zinnia you intend to plant. Fill them with potting soil.

Early in the spring, plant one zinnia seed per pot. They should be placed 1/8 inch deep in the soil. Water the seeds regularly enough to keep the soil moist, but do not allow it to get soggy.

Keep the pots indoors until it is time to transplant them, making sure that they get plenty of sun. Once the last frost date has passed, transplant them into the garden.

Soil Preparation

Use the shovel to dig up the soil of the flowerbed to a depth of 12 to 18 inches, using the yardstick to periodically check the depth. Remove any grasses or weeds. Make sure that the soil is broken up.

Scatter the manure or peat moss on the soil you have dug up. An ideal ratio is four parts of organic matter (peat moss, compost or manure) to five parts of the natural soil. This will give the soil more nutrients for the zinnias to use, and will help the plants collect more moisture.

Spread the sand out on the flowerbed. Use approximately one part sand for every nine parts combined soil and organic matter. The sand will encourage water to drain down to the level of the roots instead of pooling or draining off the surface.

Use the shovel to mix it all together. Make sure there are no large concentrations of just one soil ingredient.

Transplanting the Zinnias

Dig a small hole in the soil with the trowel. The holes should be large enough to accommodate the young zinnia's root system.

Carefully turn the pot upside down with one hand, holding the soil and the zinnia in place with the other. If the soil does not want to come out, gently loosen it with your fingers.

Hold the soil from the pot with one hand and remove the excess soil with the other. Put this soil back in the pot. The idea is to plant the zinnia and its roots, with as little potting soil as possible. Do not damage the roots of the zinnia.

Place the zinnia into the hole in the flowerbed and cover the potting soil lightly with the flowerbed soil. Make sure that the hole is filled completely. Allow the plant itself to stick up above the soil.

Repeat this process with the other zinnias. When you are done, water the soil thoroughly.

Continue to water the zinnias regularly. Until they have reached six inches tall, keep the soil moist; afterwards, water them when the top 3/8 of the soil is dry.


Things You Will Need

  • Small planting pots
  • Potting soil
  • Zinnia seeds
  • Watering can or hose
  • Round-point shovel
  • Yardstick
  • Coarse sand
  • Peat moss, compost or manure
  • Trowel