Getting it to bloom

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

Also called Moss phlox, Creeping phlox, Moss pink, Ground pink (Phlox subulata).

More about moss phlox

About Moss Phlox

Phlox subulata · also called Moss phlox, Creeping phlox · flowering

Phlox subulata is a low, evergreen, mat-forming perennial native to rocky outcrops and open woodlands of the eastern United States. It blooms prolifically in mid-spring, smothering itself with small five-petalled flowers in shades of pink, white, lavender, or crimson. Full sun and sharply drained, moderately fertile soil are essential; cutting plants back by about one-third immediately after flowering keeps the mat dense and floriferous. Classified as non-toxic to dogs, cats, and horses by the ASPCA.

Plant type: flowering

Watch for — Powdery mildew: A common fungal problem in humid summers; improve airflow by trimming post-bloom and avoid wetting foliage when watering.

The reasons moss phlox isn't blooming

Almost every non-blooming moss 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 moss 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 moss phlox to flower

Maximise sun. Give moss 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 moss phlox and get the feeding right with the moss 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

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

Moss Phlox blooming — frequently asked questions

Why won't my moss phlox flower?

Moss 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 moss phlox bloom?

Give moss 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 moss phlox normally bloom?