Getting it to bloom

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

Also called Sand phlox, Cleft phlox, Prairie phlox (Phlox bifida).

More about sand phlox

About Sand Phlox

Phlox bifida · also called Sand phlox, Cleft phlox · flowering

Phlox bifida is a low mat-forming perennial native to dry, sandy prairies, open limestone glades, and rocky bluffs from Indiana and Illinois south to Tennessee and Missouri. Each pale-lavender to white flower has five deeply notched ('bifid') petals that give the species its name, and blooms carpet the 8–15 cm mats from mid-spring to early summer. Unlike taller garden phlox, sand phlox shows excellent resistance to powdery mildew and root rot, making it one of the most trouble-free creeping phlox for hot, dry sunny gardens. The genus Phlox is listed by the ASPCA (Moss Phlox, P. subulata) as non-toxic to dogs, cats, and horses.

Plant type: flowering

The reasons sand phlox isn't blooming

Almost every non-blooming sand 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 sand 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 sand phlox to flower

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

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

Sand Phlox blooming — frequently asked questions

Why won't my sand phlox flower?

Sand 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 sand phlox bloom?

Give sand 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 sand phlox normally bloom?