Known for their unique foliage, coleus is an annual plant that has a life cycle of one year. Mostly grown for its colorful leaves, coleus has the power to turn any home garden into a visual treat. While this vibrant and leafy plant is usually grown outdoors, coleus can also be easily grown inside your home. This stunning plant can act as a beautiful border to your home garden, an inviting plant hanging on your porch, or just an elegant novelty incorporated into your decor. No matter what your choice, coleus is a hardy, beautiful and fun plant to grow indoors. Here is our guide to growing coleus indoors.
Container and Soil
Coleus needs soil that is loose well draining, but does retain a little bit of moisture. Fortunately, that’s exactly how many commercial potting soils are, most brands will work as-is just fine. Be careful to pick potting soil and not garden soil. Potting soil is specifically made for pots, and will have the right drainage and nutrients for plants to thrive.
Choosing a container is also easy as most will work. I prefer terra-cotta, but plastic, cermaic, and many others will also work. You can start your plant in a container as small as 6”, but you’ll need to upgrade to about 12” as it grows larger. If your chosen container doesn’t have drainage holes it is important to drill them out to prevent root rot.
Sowing Your Seeds
You can start growing coleus indoors by adopting three different methods: with a seed, with a seedling, or using cuttings. The easiest route is probably to start with a seedling, but we’ll cover all three here and let you choose for yourself.
If you want to sow coleus seeds you should purchase high quality seeds at a nursery or online. To stimulate germination, take 2 – 3 seeds and place them on the surface of the soil. Leave even spaces between each seed before covering them with a thin layer of soil. Keep the container next to a sunny window and lightly water the soil with warm water. Keep misting the soil with water for the next 2-3 days and check back to see if the seeds have started germinating. Once the germination process finishes, start watering just enough to wet the soil. During this process it’s best to keep the soil warm to help speed up the process. Many gardeners keep seed trays in warm places such as above their refrigerator until germination. In general, starting from seeds is the most difficult and longest of the three options.
If you wish to start with a coleus seedling, you can buy high quality coleus seedlings at a nursery or other store. Trim unhealthy roots and dig 3-4 inches in the center of the container to carefully place the seedling. Ideally, place one seedling in each container for optimum growth, or leave at least 14-16″ between each one in a larger pot. Cover the roots with soil and water just enough to wet the soil.
The third method is to use coleus cuttings. Choose a healthy coleus stem that is 2 – 6 inches long and contains nodes. Cut the bottom half and coat the lower end in rooting hormone. To help in propagation, place the stem in a container filled with water in a way that ensures the nodes are submerged. Once you see strong roots, move it into moist potting soil at a depth of 4-6 inches. Gently pat the soil over it and spray water to moisten the soil. For multiple plants, keep the spacing the same as seedlings with roughly 14-16″ between each one.
Sunlight and Temperature
Coleus thrives in warm climates and needs a minimum of 6-8 hours of sunlight to achieve lush growth. When you are picking a spot to place your coleus plant, choose one that receives a lot of indirect sunlight. You can also use artificial lighting if you do not find a place that receives a lot of sunlight. Keep grow lights at a distance of 5-6 inches, and use a low heat bulb to prevent burning your coleus plants. Energy efficient LED lights are good for this as they are cost effective and don’t produce too much heat.
Coleus plants are also very susceptible to cold and frost damage. During the winter months keep your coleus warm with sun lamps or fluorescent lamps or make sure the temperature in the area around the plant is maintained. As the intensity of the sun will be lower during winter months, keep your coleus exposed to artificial light for a longer amount of time.
Also, make sure to keep them away from any sort of drafty windows or places they might be exposed to the cold. This also goes for air conditioning vents in the summer which can have a similar negative effect on your plant.
While coleus is a hardy plant, it is not very drought tolerant. It also cannot grow in wet soil as the roots tend to rot. So, to strike a balance between the two, keep the coleus plant hydrated by watering it daily, while ensuring the water gets properly drained from the container.
As water needs to be drained frequently, which can wash away soil nutrients, you can add a liquid water-soluble fertilizer every other month to keep the plant nourished.
While the lifespan of an average coleus plant is one year, you can prolong its life by pruning. Watch out for any small flower buds and prune it before the flower buds bloom. This is because once the plant starts producing flowers and seeds it will soon die. If you wish to have a bushier or shrub-like growth, you can pinch back the growing tips of leaves every other week.
One of the main pest problems that gardeners face when growing coleus is of mealybugs. A good way to combat the mealybug pest problem is to take a brush and scrub the plant gently with water. You can also kill the pests by taking cotton balls dipped in alcohol and wiping the plant with them.
Lastly, coleus grows best in humid environments. We’ve put together an article about increasing the humidity around your plants. Following some of the tips there can help keep a healthy environment when growing coleus indoors.
Growing Coleus Indoors
Coleus is a vividly breathtaking plant that adds beauty, no matter where it grows. Apart from its attractive foliage, coleus is a tough plant that can easily grow into a lush shrub inside your home. Available in a wide variety of colors and patterns, you can easily bring any dull corner of your home to life with a potted coleus plant.
What color should coleus seedlings have?
It is good practice to check the seedlings and reject any green ones. This is because coleus is grown mainly for its colors and green seedlings will not grow up to have colorful foliage. If you’re okay with less color then green seedlings are perfectly fine to grow.
How do I know if my coleus plant has been over-watered or under-watered?
A good indicator of over-watering a plant is when the leaves turn yellow. Alternatively, if you have under-watered a plant, the leaves will start to droop.
Why are the colors on my coleus plant looking faded?
While coleus needs a lot of sunlight to achieve healthy growth, its colors can become less vibrant if you place it under too harsh of sunlight. Keep it in a spot that gets 6-8 hours of indirect light.
What’s the best tip for growing coleus indoors?
An often overlooked aspect of coleus care is the humidity. Coleus love warm, humid environments, so make sure that they retain moisture. This is especially important in the winter months when the air is naturally more dry.