Getting it to bloom

Why won't my Pampas Grass bloom? (and how to make it flower)

Also called pampas grass, common pampas grass (Cortaderia selloana).

More about pampas grass

About Pampas Grass

Cortaderia selloana · also called pampas grass, common pampas grass · flowering

A large South American ornamental grass forming a dense fountain of arching, sharp-edged blades topped in late summer by towering silvery-white feathery plumes that persist into winter. Bold and architectural, it makes a dramatic specimen or screen. Vigorous and drought-tolerant once established, though invasive in mild coastal climates and best sited with care.

Plant type: flowering

Watch for — Few or no plumes: Caused by shade, a male/non-flowering plant, or a juvenile clump. Site in full sun and allow the clump to mature; choose a known female selection for reliable plumes.

The reasons pampas grass isn't blooming

Almost every non-blooming pampas 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 pampas 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 pampas grass to flower

Maximise sun. Give pampas 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 pampas grass and get the feeding right with the pampas 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

Pampas 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 pampas grass care brief and its watering schedule — a stressed, badly watered plant rarely has the energy to flower at all.

Pampas Grass blooming — frequently asked questions

Why won't my pampas grass flower?

Pampas 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 pampas grass bloom?

Give pampas 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 pampas grass normally bloom?