Getting it to bloom
Why won't my Black-Headed Fountain Grass bloom? (and how to make it flower)
Also called Black-headed fountain grass, Black fountain grass, Moudry fountain grass (Pennisetum alopecuroides 'Moudry').
More about black-headed fountain grass
About Black-Headed Fountain Grass
Pennisetum alopecuroides 'Moudry' · also called Black-headed fountain grass, Black fountain grass · flowering
A compact, warm-season ornamental grass from eastern Asia, selected for its distinctively dark — nearly black — bottlebrush flower spikes that appear 3–5 weeks later in the season than most other fountain grass cultivars. It forms a tidy, arching mound of glossy green foliage that turns golden in autumn, and thrives in full sun with well-drained soil. The single most critical care point is that 'Moudry' self-seeds prolifically in warmer climates (Zone 7 and above), so removing spent seed heads promptly prevents naturalisation. Fountain grass (Pennisetum alopecuroides) is considered non-toxic to cats and dogs by the ASPCA.
Plant type: flowering
Watch for — Prolific self-seeding: 'Moudry' is a heavy, promiscuous seeder that can naturalise aggressively in Zones 7–9; deadhead flower spikes before seed matures to prevent unwanted spread. Check local invasive plant lists before planting.
The reasons black-headed fountain grass isn't blooming
Almost every non-blooming black-headed fountain 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 black-headed fountain 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 black-headed fountain grass to flower
- Maximise sun. Give black-headed fountain 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 black-headed fountain grass and get the feeding right with the black-headed fountain 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
Black-Headed Fountain 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 black-headed fountain grass care brief and its watering schedule — a stressed, badly watered plant rarely has the energy to flower at all.
Black-Headed Fountain Grass blooming — frequently asked questions
Why won't my black-headed fountain grass flower?
Black-Headed Fountain 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 black-headed fountain grass bloom?
Give black-headed fountain 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 black-headed fountain grass normally bloom?
Black-Headed Fountain Grass flowers across its growing season (mostly summer) and, kept fed and deadheaded, can bloom for many weeks or right up to frost.
What should I do with black-headed fountain grass after it flowers?
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.
What is the single biggest mistake stopping black-headed fountain grass flowering?
Feeding black-headed fountain grass a high-nitrogen general feed and growing it in too little sun — you get a big leafy plant and almost no flowers.
Keep reading
- Black-Headed Fountain Grass care — the full brief (light, water, humidity, problems, pet safety)
- Black-Headed Fountain Grass light needs — usually the first thing to fix for flowers
- Black-Headed Fountain Grass fertilising — the right feed for buds, not just leaves
- Should I water my plant? The simple check
- Why is my plant wilting? Wet vs dry
- Underwatered plant — signs and rehydration
- Why won't my peace lily bloom?
- Why won't my jade plant bloom?
- Why won't my tomato bloom?
- All 4114 bloom guides in the Growli library