Tips on Germinating Coleus

Obtaining Seeds

• Coleus seeds are widely available anywhere seeds are sold. Buying seeds in packets from more than one source will likely give provide different hybrids as well as a variety of colors. Since coleus can be cloned by rooting a leaf and stem, growing a variety of plants gives gardeners a chance to try out plants, reproducing select specimens. A gardener might, for instance, focus on plants that solve problems in a landscape, perhaps brightening a shaded area or providing a color counterpoint to existing plantings.

Soil

• Coleus seeds need light soil, something that can provide aeration and drainage. Such soil ensures seeds don't "drown" and also encourages the development of good root systems. African violet potting soil is such a soil. Before seeds are sown, the soil should be moistened so that it is damp, not wet.

Containers

• Any flat tray or container will do, but those with drainage -- even if it means you have to poke some holes in the bottom -- will make it easier to water later. Since the seeds will need to be in a constantly moist environment at first, containers that can be slid into a sealable plastic bag are convenient. Larger containers can be covered by glass or by taping plastic wrap to the tops.

Sowing

• Sprinkling the coleus seeds from the packet onto moistened soil will do, but to space seeds evenly, it helps to first mix the seeds with fine sand. Coleus seeds need light to germinate so don't add soil atop the seeds. Instead, just press the seeds down gently. Seal the tray in plastic or cover it with glass to finish the process.

Care

• Sealing the seeds in plastic will take care of water needs until germination. As for light, make sure the container has plenty, but don’t put the seeds in direct sun. Temperatures of 70 to 75 degrees F promote germination. Given the correct light, moisture and temperature conditions, coleus germinates in only about two weeks. After that, remove the plastic or glass and water the sprouts from the bottom of the container.