It took a few seasons, but we are hooked on coleuses. The colors are stunning, the plants require little care other than watering during dry spells, and so far the deer and rabbits have avoided them. The price of single-use annuals deters many gardeners, but the visual impact of a large stand of multi-colored coleuses in the garden will delight the eye of visitors. And the pollinators love them! Shawn has developed a method for propagating coleuses, and she’d like to share her secrets to anyone who takes time to read through this article.
Why not start with this overview video which outlines the procedures we’ll discuss in detail?
We’ve found flats of coleuses at the farmer’s market for $15-20, but usually the color is uniform. Last season, at a garden shop I frequent, I noticed tables of all-the-same boring coleuses. More expensive single-plant pots can be found for those who want to design with a color palette, but our budget does not support the habit of buying a dozen or so plants for $15 each, enjoying them for a season and composting the remains in early winter. We’ve also attempted to grow coleuses from seed and managed two living plants after months of painstaking care. My hat is off to the greenhouse growers out there. Thank you for your service to the garden community.
Our coleus collection includes several plants ordered from an online vendor, Select Seeds. All the plants (and seeds) shipped to us by Select Seeds have arrived in great shape with healthy roots. We’ve collected coleuses in all colors and shades, and each season we add a couple more with no guilt over the purchase price. Using Shawn’s proven technique these plants return season after season to wow us.
How much are we saving? In spring of 2021 we set out more than 50 plants. Let’s assign a price tag of $8 per plant (the garden shop wanted $8.98 for the uniformly shaded plants in 4 inch pots) and realize that we set out over $400 worth of plants in three large expanses of color.
And Shawn grew them all from the previous year’s crop!
Part 1 – Taking and Starting Cuttings.
Coleuses wither quickly once freezing temperatures arrive so don’t wait too long before gathering next year’s selections. Shawn takes her first cuttings in late August to give time for additional cuttings should any of the plants fail to root, and that does happen.
She carries a canning jar with water and her trusty Felco pruners (which I keep clean and sharp) to the coleus patch. She prefers a clear jar so that root growth can be easily seen but non-breakable containers work as well. She cuts a 10 inch section from either the top of the plant or from the end of a large branch.
Next Shawn snips the lower leaves to give a relatively smooth stem where new roots will form.
The cuttings are placed into the water and the harvesting continues. No chemicals or additives required. Don’t crowd the cuttings. Better to populate a second (or third) jar as needed.
The jar is placed on a south-facing window sill. We have designed and installed a kitchen plant shelf in the open space over the sink which gives a stable platform for starting cuttings. With additional lighting above that spot we can supplement during those periods when skies are cloudy.
Monitor the cuttings to keep the water level above the tender root! If the water turns murky from leaves dropping into the jar simply change the water if you desire.
This cutting showed its first roots in about a week. Shawn usually allows the roots to expand for at least 4 weeks before she attempts to pot up.
The newly potted coleuses are arranged on our indoor plant shelves alongside Shawn’s growing house plant collection. Yes, our house is alive inside and out. We love plants and make room for them in both locations. We also start garden seeds on these indoor shelves as the intense light and constant temperature make an ideal environment.
Part 2 – Winter care
Water the coleuses as needed but avoid over watering. The thirsty leaves will show obvious signs of drooping on those occasions where the gardener has been busy elsewhere. Add some water and be amazed at their rapid recovery.
Shawn prefers pots with drain holes and places them in plastic plant coasters to catch any overflow before it hits the carpet below. We’ve found it too easy to drown plants in solid containers. She has added a moisture meter to her tool collection to assist in watering, and I do not water any indoor plants so that we don’t double dip.
Shawn turns the coleuses and shuffles the collection once in a while to promote consistent growth. On rare occasion she may prune a plant to reduce its height to keep its top away from the scorching heat of the grow lights. Don’t worry if the plant looks unshapely as the goal is to preserve it until spring.
Part 3 – Prepare for the summer bonanza
In mid to late February Shawn takes cuttings from the indoor coleus collection and begins the process of rooting anew. Her goal this time is not over-wintering but preparation for the summer’s display of color. The sections will be shorter than those she snipped in the fall, usually about 4” inches max. The same process is followed to root the plants – cover the stem with water and provide adequate light.
Rooted plants are transplanted into flats under an adjustable-height grow light, and we allow them to reach for the sky. Shawn’s goal at this stage is to establish a healthy root structure that fully occupies the cubical of the flat cell before outdoor planting weather. I often deploy a small fan along with the light to simulate the wind and thereby strengthen stems.
We move our coleuses outside in early May, a couple of weeks after the average last frost date for our zone. This exposure hardens them off and prepares them for the garden. Take care to keep plants watered, and be prepared to protect them should the temperature plunge. I carry the flats into the shop on any cold nights.
Planting occurs after mid-May, when we have the time to get it done. The hard part of planting is deciding how to group the myriad colors. Water the coleuses every other day for the first two weeks then as needed through the summer.
Part 4 – Maintenance and Growing Issues
Use clean containers.
We begin any potting exercise with clean pots and flats. Our desire to economize and reuse where possible means the same containers may be used for years. After each use we wash and rinse containers with the garden hose. I then submerge them in a 5-gallon bucket of water mixed with 1 cup of bleach. Then I rinse and stack the containers to dry. Once dry they can be stored until needed.
Avoid over-watering.
Water on a schedule and/or use a moisture meter. The soil in the top of the pot may appear dry, but moisture may be available in the root area. Additional watering in that state may kill the plant. And decide who will be in charge of watering so that plants are not double-dipped. I killed some viney thing which resided in a pot on the corner of my desk because multiple times each week I dumped the remains of the previous day’s water bottle therein before heading down for breakfast. The plant appeared thirsty and the soil was dry. Or so I thought.
Fungus gnats.
I hate these varmints. Nothing worse than sitting on the couch engrossed in my favorite TV show only to have a gnat buzz up my nose! In talking with other gardeners and reading posts in several garden forums it would seem that Miracle Gro soil products, those readily available at the big box stores, may be susceptible to or more likely to include eggs or larva of these flying pests as those products seem to be a common denominator for major infestations. After our latest battle with an overpowering presence of fungus gnats in our living space we dumped the Miracle Gro and opted to purchase another soil. Time will tell if this improves the situation.
We do insert sticky traps in our indoor plantings and capture gnats that way. We’ve also sprayed the soil with Garden Sense or other organic pesticides repeatedly during outbreaks. And we work hard at watering with the correct dosage. If you are attacked by fungus gnats know that you have the sympathies of experienced gardeners everywhere.
Part 5 – Parting thoughts
Coleuses want to grow. They simply need a loving gardener to provide the proper environment. The plants will do the rest.
Growing coleuses this way implies a commitment of time, space, resources, and vigilance.
If I want the breath-taking beauty in the garden next summer I must do the mundane work behind the scenes this fall and winter.