Getting it to bloom

Why won't my Korean feather reed grass bloom? (and how to make it flower)

Also called Korean feather reed grass, fall-blooming reed grass, diamond grass (Calamagrostis brachytricha).

More about korean feather reed grass

About Korean feather reed grass

Calamagrostis brachytricha · also called Korean feather reed grass, fall-blooming reed grass · flowering

Korean feather reed grass is a shade-tolerant cool-season perennial grass prized for its late-season pink-tinged, feathery plumes that open in late summer to autumn — much later than other feather reed grasses. Forming upright, arching clumps, it thrives in part shade and moist soil, offering long interest from its airy flower heads that age to buff and persist through winter.

Plant type: flowering

The reasons korean feather reed grass isn't blooming

Almost every non-blooming korean feather reed grass 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 korean feather reed grass 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 korean feather reed grass to flower

Maximise sun. Give korean feather reed grass 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 korean feather reed grass and get the feeding right with the korean feather reed grass 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

Korean feather reed grass 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 korean feather reed grass care brief and its watering schedule — a stressed, badly watered plant rarely has the energy to flower at all.

Korean feather reed grass blooming — frequently asked questions

Why won't my korean feather reed grass flower?

Korean feather reed grass 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 korean feather reed grass bloom?

Give korean feather reed grass 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 korean feather reed grass normally bloom?