Getting it to bloom

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

Also called edging lobelia, trailing lobelia, bedding lobelia (Lobelia erinus).

More about edging lobelia

About Edging lobelia

Lobelia erinus · also called edging lobelia, trailing lobelia · flowering

A compact, profusely flowering half-hardy annual producing masses of small, vivid blue, violet, white, or red flowers from late spring until autumn frost. Ideal for edging, hanging baskets, and containers. Prefers cool, moist conditions and partial shade in hot climates. Regular watering and cool temperatures sustain its long flowering season.

Plant type: flowering

Watch for — Flowering halt in summer heat: Above 27 °C (80 °F), lobelia commonly stops blooming and may look exhausted. Move containers to a shadier spot, water consistently, and shear plants back lightly. Flowering resumes when cooler temperatures return in late summer or autumn.

The reasons edging lobelia isn't blooming

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

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

Feeding edging lobelia 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 edging lobelia to flower

Maximise sun. Give edging lobelia the sunniest spot you have — for most bedding and fruiting plants, more direct light directly means more flowers.
Switch the feed. Move off high-nitrogen feeds and use a higher-potassium "bloom" or tomato-type feed as it comes into flower.
Deadhead regularly. Remove spent flowers often to keep it producing more rather than stopping to set seed.
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 edging lobelia and get the feeding right with the edging lobelia 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

Edging lobelia 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 edging lobelia care brief and its watering schedule — a stressed, badly watered plant rarely has the energy to flower at all.

Edging lobelia blooming — frequently asked questions

Why won't my edging lobelia flower?

Edging lobelia 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 edging lobelia bloom?

Give edging lobelia 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 edging lobelia normally bloom?