Getting it to bloom

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

Also called Douglas Phlox, Tufted Phlox, Mountain Phlox (Phlox douglasii).

More about douglas phlox

About Douglas Phlox

Phlox douglasii · also called Douglas Phlox, Tufted Phlox · flowering

Douglas Phlox is a compact, mat-forming alpine perennial native to the mountain meadows and rocky slopes of western North America. It smothers itself in small, flat-faced flowers in shades of white, pink, lavender, or lilac in late spring. Extremely hardy, drought-tolerant once established, and perfect for rock gardens, walls, and raised beds.

Plant type: flowering

Watch for — Crown rot and short life: Heavy or waterlogged soil is the leading cause of plant decline. Plant in raised beds or slopes with sharply draining compost. Trim back after flowering to keep growth tight and the crown open to air.

The reasons douglas phlox isn't blooming

Almost every non-blooming douglas 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 douglas 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 douglas phlox to flower

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

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

Douglas Phlox blooming — frequently asked questions

Why won't my douglas phlox flower?

Douglas 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 douglas phlox bloom?

Give douglas 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 douglas phlox normally bloom?