Depending on your USDA growing zone, coleus can be grown outdoors as an annual or a perennial. You can also grow it as a houseplant or get the best of both worlds by planting in a container. Keep yours outside for part of the year and bring it indoors during harsh weather.
Coleus is in the Lamiaceae family, which is the same family as edible herb plants like mint, rosemary, basil, and lavender. However, some varieties are mildly toxic to people and pets alike. For this reason, it’s best to treat this plant as an ornamental and not as an edible.
If you’d like more coleus plants with beautiful foliage, you can propagate them easily. In this article, I’ll show you how! First, let’s learn a bit about coleus.
Coleus Plant Overview
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Option 1: Grow from Seed
Growing from seed is a cost-effective way to get a variety of coleus plants.
Your first option is to purchase coleus seeds. For half the cost of one coleus plant, you can obtain over 400 coleus seeds! This can provide you with potentially 400 coleus plants for less than the price of one.
You can also find coleus seeds as a part of a seed mix. Since many species grow well in the shade, they make a great companion to sprinkle in amongst other shade-loving plants. This is a perfect option for gardeners who may have a large tree, building, or other structure that creates a shady area where not much else can grow.
When growing coleus plants from seeds, you’ll have the option to either start your seeds indoors and transplant them or directly seed your plants outdoors. With so many varieties available, this method allows you to grow a wide range of plants with beautiful colors and forms.
How to Grow from Seed
Growing coleus from seeds offers the choice of indoor or outdoor cultivation.
Coleus seeds are very tiny, and they benefit from a light surface sowing. Sprinkle the seeds over your growing medium and lightly cover with a dusting of soil. They need light to germinate, so just barely cover them or press them into the soil.
Coleus seeds require temperatures between 70-75 degrees Fahrenheit (21-24 degrees Celsius) to germinate. If you’re seed starting indoors, you can achieve this using a heat mat. If you’re seed starting outdoors, then wait until all danger of frost has passed. This method is only worth it in areas with a longer growing season. Otherwise, it’s best to start them indoors at least 8-12 weeks before your last frost.
When starting coleus seeds, use a sterile seed starting mix or a soilless mix. The seeds don’t need any nutrition until after they’ve germinated, so a soilless mix works well. If this is unavailable, use high-quality potting soil, as this won’t cause any harm.
Aside from purchasing seeds, you can also obtain seeds by letting your coleus plant flower. When the flowers form, allow them to bloom fully and then die back. After the flowers die back and dry up, the seeds form. Break open the dried flower head to reveal the small coleus seeds.
Option 2: Propagation By Cuttings
The most popular and quickest way to propagate a coleus plant is by taking a cutting from an already existing plant. This is in part because coleus seeds don’t always produce true-to-type offspring. A cutting guarantees that you have an exact copy of the parent plant.
Rooting In Water
Coleus cuttings easily root in water without needing soil.
Take a cutting just below a leaf node, remove the lower leaves, and place it into a glass of water. The cutting will root in water. This plant can survive in water alone and doesn’t require soil.
If you want to eventually move your plant into soil, transplant it before very large roots develop. It can be hard to transplant into the soil once the plant has become used to growing in water.
Let a few small roots develop, dip them into rooting hormone, then place the cutting into evenly moist potting soil. Keep the soil evenly moist until new growth appears. This indicates that your rooting has been successful.
Rooting In Soil
Inserting cuttings directly into the soil to root them.
Rooting coleus in the soil is like rooting in water, except you’ll place your cutting directly into the soil. Root hormone can be used here, although it’s not necessary since plants in the Lamiaceae family are well known for their ability to root easily.
Provide a well-balanced potting mix, not a sterile seed starting mix, since cuttings benefit from the nutrients. This helps them avoid shock and put out new growth. As mentioned above, once new growth appears, you know you have successfully propagated your coleus plant.
Frequently Asked Questions
Some varieties of coleus are edible, while others are mildly toxic. For this reason, it’s best to treat these plants as ornamentals and not as an edible plant.
The short answer is, yes! They can be grown both indoors and outdoors.
Yes, in the right conditions coleus produces tiny spires of flowers.
They are tender perennials in USDA growing zone 11+ and are grown as annuals or houseplants in most of the United States.
Final Thoughts
Coleus are beautiful ornamental plants with unique foliage that add interest to your annual garden or houseplant collection. There are almost endless varieties to choose from! Now that you know how to propagate coleus plants, you’ll have an limitless supply.
