Getting it to bloom

Why won't my Arisaema speciosum bloom? (and how to make it flower)

Also called spectacular cobra lily, Himalayan jack-in-the-pulpit (Arisaema speciosum).

More about arisaema speciosum

About Arisaema speciosum

Arisaema speciosum · also called spectacular cobra lily, Himalayan jack-in-the-pulpit · flowering

Arisaema speciosum is a spectacular Eastern-Himalayan cobra lily with a single large three-parted leaf, often red-margined, atop a marbled stem, and a deep maroon-and-white striped spathe with a remarkably long, thread-like spadix tail. It grows in cool, frost-touched forests and wants humus-rich, moist, well-drained shade, dying back to a dormant tuber.

Plant type: flowering

The reasons arisaema speciosum isn't blooming

Almost every non-blooming arisaema speciosum 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 arisaema speciosum 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 arisaema speciosum to flower

Maximise sun. Give arisaema speciosum 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 arisaema speciosum and get the feeding right with the arisaema speciosum 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

Arisaema speciosum 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 arisaema speciosum care brief and its watering schedule — a stressed, badly watered plant rarely has the energy to flower at all.

Arisaema speciosum blooming — frequently asked questions

Why won't my arisaema speciosum flower?

Arisaema speciosum 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 arisaema speciosum bloom?

Give arisaema speciosum 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 arisaema speciosum normally bloom?