Getting it to bloom

Why won't my Giant Montbretia bloom? (and how to make it flower)

Also called Mason's Crocosmia, Giant Crocosmia, Falling Stars (Crocosmia masonorum).

More about giant montbretia

About Giant Montbretia

Crocosmia masonorum · also called Mason's Crocosmia, Giant Crocosmia · flowering

Giant Montbretia is a vigorous South African cormous perennial with bold pleated foliage and arching sprays of vivid orange-red flowers in mid-summer. One of the largest crocosmia species, it makes a striking architectural clump in borders. Grows best in full sun with well-drained soil. Treat as mildly toxic around pets.

Plant type: flowering

Watch for — Overcrowding: Clumps that become too dense lose vigour and flower poorly; divide every 3-4 years in spring.

The reasons giant montbretia isn't blooming

Almost every non-blooming giant montbretia 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 giant montbretia 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 giant montbretia to flower

Maximise sun. Give giant montbretia 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 giant montbretia and get the feeding right with the giant montbretia 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

Giant Montbretia 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 giant montbretia care brief and its watering schedule — a stressed, badly watered plant rarely has the energy to flower at all.

Giant Montbretia blooming — frequently asked questions

Why won't my giant montbretia flower?

Giant Montbretia 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 giant montbretia bloom?

Give giant montbretia 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 giant montbretia normally bloom?