Coleus in Sun

One of the most frequent questions I get from our customers is "Will [fill in the blank] coleus grow in full sun? It is a loaded question and my answer generally does not follow the party line of companies that promote their coleus as "Sun Coleus" or "Sun Lovers". I always use the phrase "Sun Tolerant" and it is my opinion that while some coleus can certainly survive in full sun, most benefit from some protection from the hottest sun of the day. Keep in mind that "survive" does not necessarily mean "thrive", and a coleus grown in sun will look very different than one grown in the shade. For example, the two pictures at the top of this post are both of the coleus "Bronze Pagoda". The picture on top is a specimen that has received a half day of sun. The picture below is the same variety that has gotten very little sun. Both are healthy and attractive, but few people would guess that they are the same coleus. A plant of Bronze Pagoda grown in unrelenting full sun would be even darker with overtones of brown or dark green as the plant produces more chlorophyll to protect itself from the sun. This darker coloration is not as attractive as that of a Bronze Pagoda coleus that has had some protection from the sun, but it would survive. (I'm sorry that I do not have a picture of the darkest phase, but I will try and add one later this summer.) Coleus grown in full sun are also more prone to scorched leaves, especially if they begin to wilt in the heat of the day. Frequent watering is critical when growing coleus in sun.
So, what is full sun? My definition would be a location that at no time during the day receives shade. It could be on your south-facing porch or along your driveway or next to your pool, but there are no trees or buildings that shade the area. Full sun is also a subjective term. Full sun where I live in the Great Lakes region is not as strong as full sun in Texas.
The opposite is full shade. This would be beneath an overhang, under a thick tree canopy, or inside a building. Despite the reputation that coleus have for being shade plants (it was the seed-grown bedding types that gave coleus their reputation for needing shade), full shade can be just as damaging to the health and color of your coleus as full sun. Coleus are not mushrooms!
In an ideal coleus world, coleus would receive morning sun and by noon or shortly thereafter they would be protected by a building or trees. All day dappled shade from a high tree canopy is also acceptable. Of course, we don't all have ideal conditions for our coleus so, in that case, we make do. The alternative would be to live without our favorite plant! Fortunately there are hundreds of varieties of vegetatively-propagated coleus available that are tolerant of a wide range of conditions.

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!