Coleus has always been one of my favorite houseplants with its brightly-colored foliage. Starting it from seed during the winter produces an abundance of new plants to brighten winter windows, and can even be planted outside when spring finally arrives. I think I like the element of surprise best, as planting a package of mixed seeds produces an assortment of foliage to choose from as your new favorite coleus.
Start coleus seeds at any time, as long as you can provide them with the light they need to thrive inside. A sunny western or southern window works well in the winter – but you may need to move them to a northern or eastern window in the spring when the strength of the sun increases.
Fill a flat with seed starter – or peat moss – and scatter the coleus seeds over the top. Press them into the soil with your fingers so that they are barely covered. Mist the seeds with a spray bottle to moisten the soil and cover with clear plastic wrap.
Place the seeds in a warm location – I prefer to set mine on the top of the water heater to give them gentle bottom heat. Seeds germinate in 5 to 10 days.
Remove the plastic once seedlings have emerged and move them to an area that receives bright filtered light – until they are several inches tall and can withstand direct sunlight. Keep the soil moist.
Begin pinching out the growing tip once the plants are 4 inches tall. This forces new growth along the stem and creates dense compact foliage. Pinch again when new growth has grown several inches, pinching out the centers of all branches.
Apply water-soluble fertilizer mixed to ¼ strength once a week. Use care to water your coleus seedlings before applying fertilizer to avoid damage to young roots.
Gradually move your coleus plants to more light until they can withstand direct sunlight.
Water whenever the soil feels dry to the touch, as coleus wilt quickly from a lack of water. If you notice signs of wilting, water immediate. These plants are forgiving and typically revive quickly when water is applied, but allowing your plants to wilt too many times does cause stress to the plant. Establish a good watering routine for your coleus plants to keep them in optimal health.
Move coleus outside in the spring after all danger of frost has passed and temperatures remain about 50 degrees F at night.
The amount of sunlight required depends on the coleus, but most prefer bright morning light and shelter from afternoon sun. Some coleus prefer full sun, but my experience has been that bright morning light develops deep colors without the drying effects of the afternoon sun.
Pinch out blooms as they appear. This forces energy into the production of new foliage and extends the beauty of your coleus plants. Blooming and setting seed sends the message to the plant that its life cycle is over. By removing the blooms and preventing seeds from forming, you trick the plant into thinking its job is not done.
Starting coleus from seed during the winter allows you to enjoy these cheery plants during the winter and provides you with a host of plants for outside growing in the spring.
Other work by this author:
Winter Houseplant Care
DIY: Leaf Shine for Houseplants – Use Mayonnaise
How to Make a Mini Greenhouse from a Recycled Two-Liter Soda Bottle
