Coleus under lights

Now that Spring is more than just a wistful thought, gardeners who overwinter their tender perennials indoors will be taking stock of their plants and planning their summer containers. A Coleus that has wintered inside a house may not look like it did when it came in last fall. If it was under bright grow lights and not too far from the light source it may not be the worse for wear, with fairly bright color and stocky growth. After a repotting and a trim it will, with some hardening off, be ready for its summer home. If your coleus plant has spent the winter in a window, too far from the light source, or had to compete with other plants for space under lights, it may be pale, spindly, blooming, or all three. Can this coleus be saved, or should you start over with a new one?
If you make the choice to try and rehabilitate your coleus, you first have to assess the condition of the plant. Look at the roots. White, healthy roots should be netted throughout the root ball. Signs of trouble are brown and/or scarce roots, slime or moss, and a musty or rotten smell. If any of these problems exist, try to remove as much of the spoiled soil as possible and repot the coleus in fresh soil, making sure not to over water the coleus.
Next, check the plant for pests. Look on the undersides of the leaves and in the leaf axils (where the leaves join the stem) for tufts of cotton, tiny webs, sooty and/or sticky substance, or the insects themselves. If you find pests you can remove them with a cotton swab dipped in alcohol. If it is not too large, you can give the whole coleus plant a gentle bath in tepid water with a few drops of dish detergent added. Cover the roots or pot with plastic wrap and only submerge the foliage.
The next step, if neccessary, is to give the coleus a trim, especially if it is blooming or has developed a lanky appearance stretching for light.
Finally, if you haven't already, repot your coleus. Fresh soil, a larger container, and some time-release fertilizer will get your coleus off to a great start.
Now that your coleus has been inspected, cleaned, groomed, repotted, and fertilized it is ready to begin getting gradually accustomed to the outside world again!

Overwintering Coleus: Placement and Light

It is officially the end of summer at Rosy Dawn Gardens. The coleus that were not fortunate enough to make it into the greenhouse are charred by frost and hanging limply over the sides of their pots. Inside the greenhouse, life goes on in colorful splendor, defying shorter days and cooler temperatures. Fall invariably brings a flurry of emails from our customers asking if there is a way to overwinter their coleus. So... What do you do if you do not have a greenhouse but you can't bear the thought of letting your beautiful coleus succumb to the the ravages of winter?
I won't sugarcoat it - keeping coleus in the house can be a tricky proposition. All the things that coleus love in the winter are in short supply inside the average home: good light, humidity, and good air circulation. It can be done, however, and many people do pull it off successfully by creating, in their home, the atmosphere that coleus need. Some people devote a whole spare room or basement area to their tender annuals, and some can only find a single window or corner of a room to spare for the cause. Either way, the goal of keeping the coleus alive until spring can be achieved.
The first consideration has to be light, since window placement is often the primary factor when deciding where your coleus are going to spend the winter. Unfortunately, windows in the average home seldom provide the ideal environment for coleus. If you place the coleus too close to the window they may be subjected to drafts and injured by contact with cold glass. Often there are heat vents in front of windows which can blast the coleus with hot, dry air. Windows often provide inconsistent levels of light. Your coleus could sit in relative darkness during the early part of the day and be blasted by too much direct sun in the afternoon. Plus, the coleus have to be very close to the window. Positioning your coleus a mere 12-18 inches away from the glass may not provide enough light for good health, even at the brightest point in the day. Despite the reputation of coleus as a shade-loving plant, they will not thrive in the low light conditions of the average home and, at best, lean and stretch for the light and become spindly. The simplest answer to this problem is to provide artificial light to supplement or substitute for natural light.
There are a number of options when purchasing artificial light. No-frills, 48" fluorescent shop light fixtures are very inexpensive at hardware and home-improvement stores and are the best buy for the amount of light you get. They can be suspended on chains, affixed to a stand, or set up between two stacks of bricks or other sturdy, non-flammable material. Standard fluorescent bulbs are economical and will do the trick for a few months indoors, or you can use the more costly grow-light bulbs for a full spectrum of light. I would definitely recommend grow-lights if your indoor growing situation is permanent. There are other types of grow-light fixtures available in all sorts of sizes and configurations, ranging from little light strips that can be mounted under a cupboard to stand-alone fixtures like goose neck lamps. Spotlights can be ceiling-mounted, but most grow lights have to be within a few inches of the top of the leaves to be effective. The most deluxe (and costly) option is a ready-to-use indoor gardening center that has one to three levels and all of the bells and whistles for growing coleus and other tender plants inside the house. One could build a similar set-up with minimal carpentry skills and some ingenuity. For many years before erecting our first greenhouse I started seeds and overwintered tender plants under homemade banks of lights in the basement and in other nooks and crannies in the house. I found it preferable to have free-standing fixtures and be independent of our limited windowsill space. Grow lights can also be used to supplement natural light in front of a window or door wall. Suspending or supporting fixtures above your plants will give you the ability to provide your coleus brighter light on cloudy days and extending the short days of mid-winter. There are other types of grow lights on the market as well. The newest type are energy-efficient LED grow lights, and if you want to make the investment it would be a great way to go. I have never used them, so I cannot offer instruction on how to use them. Comments from readers would be welcome!
If a windowsill is your only option, then you have to make do. Coleus have been kept over the winter for generations in a kitchen window, sometimes as nothing more than a cutting in a jar of water. It may not have been the loveliest of creatures come spring, but the coleus survived to see another summer.

Introducing a New Coleus

We occasionally get letters from customers that are excited because they have discovered a new coleus seedling or sport (mutation). I can understand that excitement! We see nifty sports and seedlings from time to time, and of course we always hope that they are something new and unique. However, we have to remember that most new discoveries end up on the compost heap. Appearance is just one of many important factors that we, as gardeners, are looking for. At Rosy Dawn Gardens we are not interested in introducing a plant that is difficult to propagate and cannot be reliably grown in a wide range of conditions. We have to prove to ourselves that any new coleus is a garden-worthy coleus and not just another hot-house beauty that needs to be coddled and protected in order to survive.

At Rosy Dawn Gardens, introducing a new worthwhile variety takes patience and time. First we collect data about the plant so we can create a full description to present to potential buyers. Cuttings of the coleus need to be taken to see how well it propagates. The resulting plants are then grown outdoors during the summer in several different locations: full sun, shade, morning sun, etc. They are grown in the ground and in containers. They are grown both alone and in combination with other coleus and container plants. We take notes about its height at maturity, when and if it blooms, its growing habit (does it grow upright, bushy, or trail?). Then we watch to see how well the plant overwinters. If it does well with the rigors of outdoor life, grows vigorously, resists disease, overwinters well, and propagates easily, then we might have a coleus with more than a pretty face to recommend it! Usually we repeat the process for two to three years before introducing a coleus to commerce.

This year we have introduced a lovely coleus called 'Chloe' (shown), a seedling out of 'Flame Thrower'. She is a bushy coleus with a mounded form and she grows a bit larger than her parent. Her pink color and green edge sparkle just like her namesake: our granddaughter Chloe! We have been evaluating this coleus for two full years and have been very pleased with all facets of her growth habit and vigor. We hope you agree!

Coleus in Hanging Baskets

I often wonder how many people use coleus for hanging baskets? We use hanging baskets a lot here at Rosy Dawn Gardens. All of our trailing and mounding coleus are kept in them and they do marvelously with the good light and air circulation. Of course, we are pinching and cutting on them all the time, but that only makes them more lush and beautiful. Three or four starter plants, depending on how vigorous the variety of coleus, will create a gigantic hanging basket by the end of summer. Some of the trailing coleus, like Trailing Burgundy, will create long ropes, while others like Trailing Garnet Robe, Trailing Rose, and Trailing Plum Brocade will spread horizontally. Mounding coleus, such as Purple Duckfoot, Charlie McCarthy, Black Lace, and Cantigney Royale will create a virtual ball of foliage. Pinching out the growing tips and not allowing the plant to bloom is the key to having a good shape for your hanging coleus basket. (Blooming coleus will be covered in a post coming very soon)
Make sure you hang your coleus basket where it is convenient to water one or more times a day. A hot, breezy summer day, even if the basket is hanging under the eaves of a building, will require you to water more frequently than a cloudy, rainy day. A coleus hanging basket, when boosted lightly from the bottom, should feel appropriately heavy. Too light, and it will need watering. Too heavy, and it is being over watered. Many hanging baskets have a reservoir in the the base and if a basket consistently feels too heavy you should regularly tip it sideways a bit to empty the base if it has become waterlogged.
Coleus hanging baskets do well when they are fertilized with a timed release fertilizer or are regularly treated with a liquid fertilizer at half strength. Too much fertilizer can cause lanky growth and affect the color of your coleus. It is also helpful to use a product to improve the retention of moisture in your hanging basket.
Light is an important consideration when considering where to hang your coleus basket. I can think of no instance where a hanging basket of coleus should be placed in full, unrelenting sun. Hanging baskets, by design, do not have a great deal of soil volume so they will be light enough to hang safely. They do not hold enough potting mix to sustain a coleus through a sunny, breezy day without the coleus becoming damaged. Coleus hanging baskets do well under the eaves of a building, it the dappled shade of large trees, or against a fence or wall where it receives some morning sun but is protected from the sun at high noon and in the afternoon when the sun gets hottest. Too much shade is not good for your coleus basket either. Shade will not encourage good color and the growth can become spindly as the coleus reaches for more light. One good thing about hanging baskets is that if they don't seem happy they are easy to move!