Getting it to bloom

Why won't my tall purple moor grass bloom? (and how to make it flower)

Also called tall purple moor grass, moor grass, purple moor grass (Molinia arundinacea).

More about tall purple moor grass

About tall purple moor grass

Molinia arundinacea · also called tall purple moor grass, moor grass · flowering

Tall purple moor grass is an elegant, clump-forming deciduous grass producing tall, wiry flowering culms that arch and sway gracefully in the lightest breeze. It thrives in moist, acidic to neutral soils in full sun or light shade, offers spectacular golden autumn colour, and naturally sheds its flower stems over winter with minimal maintenance required.

Plant type: flowering

The reasons tall purple moor grass isn't blooming

Almost every non-blooming tall purple moor 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 tall purple moor 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 tall purple moor grass to flower

Maximise sun. Give tall purple moor 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 tall purple moor grass and get the feeding right with the tall purple moor 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

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

tall purple moor grass blooming — frequently asked questions

Why won't my tall purple moor grass flower?

tall purple moor 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 tall purple moor grass bloom?

Give tall purple moor 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 tall purple moor grass normally bloom?