Sunday, February 15, 2009
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.