Coleus

May 18, 2024

Move over Impatiens and make way for Coleus.

A decade or two ago, Impatiens were the most widely planted shade loving plant in the annual garden.  But the fungus Downy Mildew quickly caused Impatiens to take a dive bomb.

Today, Coleus has claimed top spot as the plant that is given most space on the display benches of every garden centre.

Coleus is a lush tropical plant known only for its foliage.  Its flowers are practically non-existent while the foliage comes in an array of every colour imaginable.  Foliage can be solid coloured, but is mostly veined or margined in unlimited combinations.

Coleus is a quick and vigorous grower that shows best in containers or mass plantings in the garden.  Plant Coleus 18 inches apart, and they will quickly form a thick blanket over the soil below.

When planting in pots, use 3 Coleus for small containers that are up to 15 inches in diameter.  For larger pots, jump to 5 or 6.  Don’t bother using the thriller, filler and spiller concept when planting Coleus because they are best planted without competition.

Coleus thrives in shade, but readily adapts to locations with full sun.  Their favorite location is the east side of the house where they enjoy morning sun but are shaded from hot afternoon sun.

If Coleus plants are grown in hanging baskets or containers, they will want to be watered daily.  Add more water during hot summer dry spells.  Coleus are not fond of waterlogged soil but would rather be planted in gardens with good drainage.

Fertilizing is hardly necessary, but the plant will reward you with improved vigour and colour if given slow-release plant food at planting time.   Supplement with a balanced water-soluble plant food through summer.

As soon as Coleus is planted, it flourishes quickly, and appears fully mature in a matter of weeks.  By the end of July it begins to lose its luster and will often produce less- than-attractive flower spikes at the top of each plant.  Prune the flowers and a portion of the stem back and the plant will respond with fresh new foliage.

At the end of the year, bring Coleus indoors to be grown as a tropical houseplant.  Prune the plant back and transplant into a pretty container suitable for a windowsill or floor plant.  Place in a south or west facing window that receives ample light.  In spring, once danger of frost is past, put the Coleus back outside for another season of performance.