How To Grow Coleus From Seeds

Anyone who has ever tried rooting Coleus blumei from cuttings knows how easy it is to grow them.

Many of us got our first house plant – a coleus that way, but did you ever try growing them from seed for a really plentiful supply and to avoid having to winter over so many?

Growing coleus from seed is easy… it’s almost like growing radishes!

Coleus seeds are a little larger than those of petunias, and although they may be sown at any time of the year when warmth can be furnished, seeds sown during February will produce plants of just the right size for outdoor use in May.

Seedlings exhibit a diversity of color, leaf forms and markings. This makes growing coleus seedlings particularly interesting, you wonder what possible cross or hidden ancestry produced the variations.

By the time most coleus start to bloom, they are determined to bloom, and no amount of pinching out buds will long delay the inevitable sprouting of buds all over the plant. Allow some bloom stalks mature seed, then trim back the whole plant, or start new plants from cuttings.

Some types of coleus bloom quickly; others grow the whole long season of a Florida summer without so much as a bud. Naturally, the more kinds blooming at once, the more possibilities for crosses to produce plants of different appearance.

Related Reading: Coleus Care Questions & Answers

For example, having a plant with plain smooth leaves of green, with tan center marking and pinkish reverse, and others with slender, partially crumpled brightly colored leaves, and others with ruffled leaves.

I’ve had seedlings with slender crumpled leaves showing the green and tan color, and ruffled ones in various combinations of pink and tan.

Video: University Of Florida’s Coleus Breeding Program

Coleus seed shatter easily, and the pods should be removed as soon as they turn slightly yellow. When dry, the seed may be rubbed out between the hands, and freed of chaff by blowing lightly. Seed may be obtained from practically any reputable seed house as well.

Since the seed are fine, they must be planted in well prepared soil, in flats or other containers which may be protected from hot sunshine and dashing rain.

Use a planting medium like one used for african violet care in a pot three or four inches deep or any other type of container with plenty of drainage.

Light rich soil, but not over-fertilized should be used, with the top soil sifted through a piece of screen wire so it is quite fine.

Containers should be filled well, so that seedlings will not become stemmy reaching for the light. After the soil is quite smooth, and wet thoroughly, sprinkle the seed very thinly on top of the moist soil, and sift over them just enough of the finest soil to hide the seed from sight.

An easy method for planting the seed is to mix it with a bit of finely screened peat or clean, dry sand and sprinkle over the seed bed.

Do not cover the seed, but give the top of the bed a gentle firming with the palm of your hand. Set the container in warm water so that moisture comes from the bottom and will not disturb the seed.

When the water has reached the top of the soil, remove the pot from the water and place a piece of glass or cellophane over the top to conserve moisture.

Place the container in a shaded, warm place to await germination. Coleus seed will not come up well if they dry out, or if the temperature drops much below 60 degrees. If seed are fresh, and conditions satisfactory, seed will begin to germinate by the fifth day.

The seedlings have a characteristic appearance, and are easily recognizable, once one has seen them. They should immediately have plenty of light, with direct sunlight when not too hot, but at no time should the soil dry out, as the plants have very shallow roots.

Transplanting will be necessary as soon as they begin to crowd each other in the seed bed.

Coleus are as easy to transplant as anything you’ll ever grow. Put them in individual pots, planters or group them in a flat a few inches apart.

Video: Starting Seeds

Large or small, coleus should never be crowded, and seedlings should be transplanted promptly to prevent crowding. They are easily moved at any age. Plants should be protected from heavy rains, very hot sunlight, and high winds, for some time, and those with crepey foliage are subject to storm damage at any age.

Seedling coleus usually make well shaped plants, with uniform branches. Bright colors do not develop until the plants are some size, though occasionally a distinctive leaf pattern will be unmistakable when the first true leaves appear.

Plants unsatisfactory in leaf form or color should not be permitted to bloom, though they may be kept for a single season.

Even among seedlings from the most showy sorts, some dull or stemmy plants will result, and a few plants will remain pale and spindly with the same treatment under which others become strong and husky.

By the time coleus seedlings are two inches tall, they may receive the same care given any other coleus of their particular type.

Coleus leaves vary in size from fingerprint measure to those almost as broad as a dinner plate. They may be satiny smooth or ruffled, crepey and pebbly, scalloped or picoted, in texture.

Colors range from velvety purple-black, with green edges, to various white and green combinations. There are shades of brown like pansy faces, and all shades of red and pink, combined with green, yellow, and cream.

There is a fascination about coleus which increases as one works with them.

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Uses of Coleus

When seedlings have four to six leaves you’re ready to use coleus like paint from a tray wherever a spot of rich color and velvety texture is needed.

Almost no two seedlings will have the exact same leaf pattern or coloring. At this time pinch out the top two new leaves to encourage branching and a more sturdy, bushy plant.

Coleus are ideal for formal gardens, in a border, or to heighten the effect of some blossoming plant by repeating its flower hue. I’ve seen this done effectively in a garden surrounding the museum at Denver, Colorado.

They cannot be excelled for use in planter boxes, urns, and porch boxes outdoors.

They may be combined with begonias, petunias, wandering jew, or any other plant commonly used in this sort of planting.

In Missouri last summer I saw a most striking planting of assorted coleus seedlings on the east side of a shade garden where they received full sun until early afternoon.

On either side of the garden entrance two white ornamental iron urns were set, planted with coleus whose leaves were of the richest wine velvet with a tiny leaf edge of green.

To take up the reddish-purple of the coleus leaves, this landscaper was smart in using something unusual… achimenes.

When you set seedlings outdoors they may need to be shaded for a few days; but once they are established, they can stand plenty of sunlight, and it seems to make their colors more vivid.

However, the best outdoor use of coleus is to bring color to a spot not reached by sun – for unlike so many plants, coleus tolerates shade.

The best window garden specimens are often those grown against a plate glass shop window or one given sole domain in someone’s bright picture window.

For such individual use, a good variety is one whose leaves are deep, soft red edged delicately in light green. Specimen plants should be turned frequently and judicious pinching of new growth stimulates denseness.

Likes and Dislikes

Coleus like a fertile soil and liberal doses of organic fertilizer such as fish emulsion or liquid food. Care should be taken not to overwater.

While plants do grow quickly and use much moisture, extreme wetness, especially if conditions are cool, will cause rotting.

Coleus have one foe-the cottony mealybug. If your plants get a good case of this gnawing little horror, pull out the whole mess; then buy a packet of seed and grow some new plants.

Try coleus in your busiest living area for they are wonderfully savable. No cause for concern when over zealous pets or youngsters in a fast game of indoor ball devastate your plants.

If they’re coleus you can pick up the pieces, stick them in water in a glass or jar and soon you’ll have rooted coleus cuttings ready for potting. And quite decorative they are in process!

Even a badly battered mature plant will put out new growth, particularly if it can be moved to an outdoor location.

Coleus are ideal for the casual grower who is more interested in creating a pleasing decorative effect than in the plants themselves.

They are a standby as color accent in the all foliage planting and they are encouraging material for children or any beginning gardener. No waiting for blooms; with coleus the color is there from the first!

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