Getting it to bloom

Why won't my Wild Blue Phlox bloom? (and how to make it flower)

Also called Wild Blue Phlox, Wild Sweet William, Louisiana Phlox, Woodland Phlox (Phlox divaricata).

More about wild blue phlox

About Wild Blue Phlox

Phlox divaricata · also called Wild Blue Phlox, Wild Sweet William · flowering

Phlox divaricata is a delicate native woodland phlox of eastern North America, producing loose clusters of fragrant, pale blue to lavender flowers in mid-spring above semi-evergreen foliage. It thrives in dappled shade under deciduous trees, making it ideal for naturalising in woodland gardens. An excellent companion to spring bulbs and ferns.

Plant type: flowering

Watch for — Summer dormancy or foliage decline: In hot, dry summers P. divaricata may go partially dormant after flowering, with foliage yellowing or dying back. This is normal behaviour. Maintain soil moisture and the plant will typically re-flush in cooler autumn conditions.

The reasons wild blue phlox isn't blooming

Almost every non-blooming wild blue phlox 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 wild blue phlox 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 wild blue phlox to flower

Maximise sun. Give wild blue phlox 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 wild blue phlox and get the feeding right with the wild blue phlox 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

Wild Blue Phlox 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 wild blue phlox care brief and its watering schedule — a stressed, badly watered plant rarely has the energy to flower at all.

Wild Blue Phlox blooming — frequently asked questions

Why won't my wild blue phlox flower?

Wild Blue Phlox 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 wild blue phlox bloom?

Give wild blue phlox 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 wild blue phlox normally bloom?