Growli

Getting it to bloom

Why won't my Coleus bloom? (and how to make it flower)

Also called painted nettle, flame nettle, Plectranthus scutellarioides (Coleus scutellarioides).

About Coleus

Coleus scutellarioides · also called painted nettle, flame nettle · flowering

Coleus is a tender perennial grown as a bedding annual or houseplant for its boldly patterned leaves in lime, burgundy, pink, and chocolate. Pinching keeps it bushy; flowering should be removed to extend foliage life. Mildly toxic to pets through essential oils.

Coleus scutellarioides (also placed in Plectranthus/Solenostemon), a mint-family (Lamiaceae) plant native to tropical and subtropical Asia through to northern Australia.

Plant type: flowering

Watch for — Leggy stems: Pinch flowers and growing tips every 1-2 weeks.

Sources: plants.ces.ncsu.edu, missouribotanicalgarden.org, aspca.org

The reasons coleus isn't blooming

Almost every non-blooming coleus traces back to one of these, roughly in order of how common they are:

  1. Too little sun — most of these need full sun (or very bright light) to flower well; shade gives leaves, not blooms.
  2. Too much nitrogen feed, driving lush foliage at the expense of flowers (very common with general or lawn feeds).
  3. The plant has not been deadheaded, so it stops flowering once it sets seed.
  4. Irregular watering — drought or waterlogging at the budding stage makes buds abort.
  5. It is still too young or was checked by a transplant and is rebuilding before flowering.

Feeding coleus a high-nitrogen general feed and growing it in too little sun — you get a big leafy plant and almost no flowers.

The fix — how to get coleus to flower

  1. Maximise sun. Give coleus the sunniest spot you have — for most bedding and fruiting plants, more direct light directly means more flowers.
  2. Switch the feed. Move off high-nitrogen feeds and use a higher-potassium "bloom" or tomato-type feed as it comes into flower.
  3. Deadhead regularly. Remove spent flowers often to keep it producing more rather than stopping to set seed.
  4. Water consistently. Keep moisture even through budding and flowering — drought-then-flood swings make buds drop.

Light and feeding do most of the heavy lifting here. Dial in the spot with the light guide for coleus and get the feeding right with the coleus fertilising schedule — the wrong feed (too much nitrogen) is one of the most common silent reasons a healthy plant makes leaves instead of flowers.

Bloom season and what to expect

Coleus flowers across its growing season (mostly summer) and, kept fed and deadheaded, can bloom for many weeks or right up to frost.

Post-bloom care so it flowers again

Deadhead, keep feeding lightly, and many will rebloom; collect seed from the best plants at the end of the season if you want to grow them again.

For everything else this plant needs day to day, see the full coleus care brief and its watering schedule — a stressed, badly watered plant rarely has the energy to flower at all.

Coleus blooming — frequently asked questions

Why won't my coleus flower?

Coleus blooms on the season's growth given enough sun, warmth and the right feed — there is no cold or photoperiod trick, just good growing conditions and a bloom-leaning feed. The most common reason it is not happening: Too little sun — most of these need full sun (or very bright light) to flower well; shade gives leaves, not blooms.

How do I make coleus bloom?

Give coleus the sunniest spot you have — for most bedding and fruiting plants, more direct light directly means more flowers. Move off high-nitrogen feeds and use a higher-potassium "bloom" or tomato-type feed as it comes into flower.

When does coleus normally bloom?

Coleus flowers across its growing season (mostly summer) and, kept fed and deadheaded, can bloom for many weeks or right up to frost.

What should I do with coleus after it flowers?

Deadhead, keep feeding lightly, and many will rebloom; collect seed from the best plants at the end of the season if you want to grow them again.

What is the single biggest mistake stopping coleus flowering?

Feeding coleus a high-nitrogen general feed and growing it in too little sun — you get a big leafy plant and almost no flowers.

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