Getting it to bloom

Why won't my Purple Paintbrush bloom? (and how to make it flower)

Also called Purple paintbrush, Prairie paintbrush, Purple Indian paintbrush (Castilleja purpurea).

More about purple paintbrush

About Purple Paintbrush

Castilleja purpurea · also called Purple paintbrush, Prairie paintbrush · flowering

Castilleja purpurea is a perennial prairie wildflower native to calcareous grasslands, savannas, and open woodland edges from southern Missouri and Kansas south through Texas, favouring limestone gravels and calcareous clays. Like all paintbrushes it is hemiparasitic, fixing itself to the roots of neighbouring grasses to supplement water and mineral uptake — it cannot sustain itself without a grass host. The showy bracts range from purple and purplish-red to occasional yellow or white and bloom in spring, making it valuable for pollinator meadow plantings. It is a secondary selenium accumulator and is considered mildly toxic to pets.

Plant type: flowering

The reasons purple paintbrush isn't blooming

Almost every non-blooming purple paintbrush 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 purple paintbrush 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 purple paintbrush to flower

Maximise sun. Give purple paintbrush 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 purple paintbrush and get the feeding right with the purple paintbrush 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

Purple Paintbrush 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 purple paintbrush care brief and its watering schedule — a stressed, badly watered plant rarely has the energy to flower at all.

Purple Paintbrush blooming — frequently asked questions

Why won't my purple paintbrush flower?

Purple Paintbrush 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 purple paintbrush bloom?

Give purple paintbrush 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 purple paintbrush normally bloom?