Getting it to bloom

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

Also called Purple Mullein, Phoenicean Mullein, Rosette Mullein (Verbascum phoeniceum).

More about purple mullein

About Purple Mullein

Verbascum phoeniceum · also called Purple Mullein, Phoenicean Mullein · flowering

Purple Mullein is an elegant, slender-stemmed biennial or short-lived perennial from central and eastern Europe, bearing tall wands of open, saucer-shaped flowers in shades of violet, pink, lilac, or white above a low, smooth-leaved basal rosette. Far more delicate-looking than woolly mulleins, it suits cottage gardens, prairie planting, and the front of sunny mixed borders.

Plant type: flowering

Watch for — Short lifespan (dies after flowering): As a monocarpic biennial or short-lived perennial it dies after setting seed; allow some self-seeding or collect and resow seed annually to maintain the planting — named cultivars will not come true from seed.

The reasons purple mullein isn't blooming

Almost every non-blooming purple mullein 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 purple mullein 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 purple mullein to flower

Maximise sun. Give purple mullein 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 purple mullein and get the feeding right with the purple mullein 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

Purple Mullein 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 purple mullein care brief and its watering schedule — a stressed, badly watered plant rarely has the energy to flower at all.

Purple Mullein blooming — frequently asked questions

Why won't my purple mullein flower?

Purple Mullein 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 purple mullein bloom?

Give purple mullein 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 purple mullein normally bloom?