Getting it to bloom

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

Also called Lungwort, Common Lungwort, Jerusalem Cowslip, Spotted Dog (Pulmonaria officinalis).

More about lungwort

About Lungwort

Pulmonaria officinalis · also called Lungwort, Common Lungwort · flowering

Pulmonaria officinalis is a shade-loving, semi-evergreen rhizomatous perennial native to damp woodland and scrub across central and southern Europe. It is valued as an early-spring groundcover, producing clusters of funnel-shaped flowers that open pink and mature to blue-violet, followed by large, white-spotted leaves that remain attractive all summer. The most important care principle is consistent shade and moisture — hot sun and dry soil cause the leaves to scorch and collapse by midsummer. Lungwort contains pyrrolizidine alkaloids and saponins and should be considered toxic to cats and dogs.

Plant type: flowering

Watch for — Powdery mildew: The most common problem: white mealy coating develops on leaf surfaces in warm, dry summers or where air circulation is poor; cut back all foliage to the ground after flowering and the fresh summer flush typically emerges clean.

The reasons lungwort isn't blooming

Almost every non-blooming lungwort 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 lungwort 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 lungwort to flower

Maximise sun. Give lungwort 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 lungwort and get the feeding right with the lungwort 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

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

Lungwort blooming — frequently asked questions

Why won't my lungwort flower?

Lungwort 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 lungwort bloom?

Give lungwort 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 lungwort normally bloom?