Getting it to bloom

Why won't my Viper's Bugloss bloom? (and how to make it flower)

Also called Viper's Bugloss, Blueweed, Common Viper's Bugloss (Echium vulgare).

More about viper's bugloss

About Viper's Bugloss

Echium vulgare · also called Viper's Bugloss, Blueweed · flowering

Viper's bugloss is a bristly biennial or short-lived perennial native to dry, chalky grassland, roadsides, and coastal shingle across Europe and the UK. It produces tall spikes of brilliant violet-blue, funnel-shaped flowers from June to August that are irresistible to bumblebees, honeybees, and butterflies. The single most important care fact is that it demands full sun and excellent drainage — rich or waterlogged soil produces floppy, disease-prone plants with fewer flowers. According to the ASPCA, Echium vulgare is classified as toxic to horses via pyrrolizidine alkaloids; its status for cats and dogs is not separately listed, so treat it as mildly-toxic for household pets.

Plant type: flowering

The reasons viper's bugloss isn't blooming

Almost every non-blooming viper's bugloss 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 viper's bugloss 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 viper's bugloss to flower

Maximise sun. Give viper's bugloss 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 viper's bugloss and get the feeding right with the viper's bugloss 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

Viper's Bugloss 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 viper's bugloss care brief and its watering schedule — a stressed, badly watered plant rarely has the energy to flower at all.

Viper's Bugloss blooming — frequently asked questions

Why won't my viper's bugloss flower?

Viper's Bugloss 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 viper's bugloss bloom?

Give viper's bugloss 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 viper's bugloss normally bloom?